Pub Date : 2024-10-28DOI: 10.1007/s00269-024-01299-0
Alexander F. Redkin, Andrey M. Ionov, Alexey N. Nekrasov, Andrey D. Podobrazhnykh, Rais N. Mozhchil
Studies conducted in NaF-containing hydrothermal fluids have shown that the oxide compounds Sb5+ are unstable at 800 °C, Рtotal = 200 MPa and fO2 (fH2) specified by Co–CoO and Ni–NiO buffers interact with the Pt material of the ampoule, forming antimony intermetallics with platinum on the inner surface of the ampoule. The formation of the following intermetallics was established through the analysis of data obtained from studies conducted on an electronic microscope: Pt90.3±0.8Sb9.7 (~ Pt10Sb), Pt82.8±1.3Sb17.2 (~ Pt5Sb) and Pt69.2±4.4Sb30.8. Pt10Sb compound which was obtained on the inner surface of the Pt ampoule is the limiting solid solution of antimony in platinum at 800 °C. It exhibits a cubic crystal system (Fmoverline{3}m) with a lattice constant of a = 3.943(3) Å and forms an underdeveloped surface < 111>. Pt5Sb compound, presumably hexagonal P6/mmm crystal system with unit cell parameters a = b = 4.56(4), c = 4.229(2) Å, α = β = 90°, γ = 120°, forms a thin film (≤ 10 μm) on the Pt surface and appears to be a metastable phase. The intermetallic compound of Pt69Sb31 is a rapidly cooled melt of appropriate composition.
A mechanism for deep penetration of Sb into the walls of the Pt ampoule is proposed.
在含 NaF 的热液中进行的研究表明,氧化物 Sb5+ 在 800 ℃、Рtotal = 200 MPa 和 Co-CoO 和 Ni-NiO 缓冲剂规定的 fO2(fH2)条件下不稳定,会与安瓿的铂材料相互作用,在安瓿内表面与铂形成锑金属间化合物。通过分析电子显微镜研究获得的数据,确定形成了以下金属间化合物:Pt90.3±0.8Sb9.7(~ Pt10Sb)、Pt82.8±1.3Sb17.2(~ Pt5Sb)和 Pt69.2±4.4Sb30.8。在铂安瓿内表面获得的 Pt10Sb 化合物是铂中锑在 800 °C 时的极限固溶体。它呈现出晶格常数为 a = 3.943(3) Å 的立方晶系(Fm/overline{3}m/),并形成一个不发达的表面 <111>。Pt5Sb 化合物推测为六方 P6/mmm 晶系,单胞参数 a = b = 4.56(4),c = 4.229(2)埃,α = β = 90°,γ = 120°,在铂表面形成一层薄膜(≤ 10 μm),似乎是一种可转移相。Pt69Sb31 金属间化合物是一种具有适当成分的快速冷却熔体。
{"title":"Interaction of platinum with antimony-bearing compounds in NaF fluids at 800 °C and 200 MPA","authors":"Alexander F. Redkin, Andrey M. Ionov, Alexey N. Nekrasov, Andrey D. Podobrazhnykh, Rais N. Mozhchil","doi":"10.1007/s00269-024-01299-0","DOIUrl":"10.1007/s00269-024-01299-0","url":null,"abstract":"<div><p>Studies conducted in NaF-containing hydrothermal fluids have shown that the oxide compounds Sb<sup>5+</sup> are unstable at 800 °C, <i>Р</i><sub>total</sub> = 200 MPa and <i>f</i>O<sub>2</sub> (<i>f</i>H<sub>2</sub>) specified by Co–CoO and Ni–NiO buffers interact with the Pt material of the ampoule, forming antimony intermetallics with platinum on the inner surface of the ampoule. The formation of the following intermetallics was established through the analysis of data obtained from studies conducted on an electronic microscope: Pt<sub>90.3±0.8</sub>Sb<sub>9.7</sub> (~ Pt<sub>10</sub>Sb), Pt<sub>82.8±1.3</sub>Sb<sub>17.2</sub> (~ Pt<sub>5</sub>Sb) and Pt<sub>69.2±4.4</sub>Sb<sub>30.8</sub>. Pt<sub>10</sub>Sb compound which was obtained on the inner surface of the Pt ampoule is the limiting solid solution of antimony in platinum at 800 °C. It exhibits a cubic crystal system <span>(Fmoverline{3}m)</span> with a lattice constant of <i>a</i> = 3.943(3) Å and forms an underdeveloped surface < 111>. Pt<sub>5</sub>Sb compound, presumably hexagonal <i>P</i>6/<i>mmm</i> crystal system with unit cell parameters <i>a</i> = <i>b</i> = 4.56(4), <i>c</i> = 4.229(2) Å, <i>α</i> = <i>β</i> = 90°, <i>γ</i> = 120°, forms a thin film (≤ 10 μm) on the Pt surface and appears to be a metastable phase. The intermetallic compound of Pt<sub>69</sub>Sb<sub>31</sub> is a rapidly cooled melt of appropriate composition.</p><p>A mechanism for deep penetration of Sb into the walls of the Pt ampoule is proposed.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142524480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-26DOI: 10.1007/s00269-024-01300-w
Yuqing Yin, Leonid Dubrovinsky, Andrey Aslandukov, Alena Aslandukova, Timofey Fedotenko, Konstantin Glazyrin, Gaston Garbarino, Igor A. Abrikosov, Natalia Dubrovinskaia
The rhenium carbide Re3C was predicted to be stable under high pressure and expected to have high hardness and low compressibility. In this study, we realise the synthesis of Re3C at megabar pressures of 105(3) and 140(5) GPa in laser-heated diamond anvil cells and characterise its structure using synchrotron single-crystal X-ray diffraction. The structure of Re3C has the monoclinic space group C2/m and is built of CRe7 capped octahedra. Our combined ab initio calculations and quantitative topological analysis support experimental structural data and further deepen the understanding of the chemical bonding in the newly synthesized compound.
据预测,碳化铼 Re3C 在高压下是稳定的,并且具有高硬度和低可压缩性。在本研究中,我们实现了在 105(3) 和 140(5) GPa 的兆帕压力下,在激光加热的金刚石砧单元中合成 Re3C,并利用同步辐射单晶 X 射线衍射对其结构进行了表征。Re3C 的结构具有单斜空间群 C2/m,由 CRe7 冠八面体构成。我们的综合 ab initio 计算和定量拓扑分析为实验结构数据提供了支持,并进一步加深了对新合成化合物化学键的理解。
{"title":"High-pressure synthesis of rhenium carbide Re3C under megabar compression","authors":"Yuqing Yin, Leonid Dubrovinsky, Andrey Aslandukov, Alena Aslandukova, Timofey Fedotenko, Konstantin Glazyrin, Gaston Garbarino, Igor A. Abrikosov, Natalia Dubrovinskaia","doi":"10.1007/s00269-024-01300-w","DOIUrl":"10.1007/s00269-024-01300-w","url":null,"abstract":"<div><p>The rhenium carbide Re<sub>3</sub>C was predicted to be stable under high pressure and expected to have high hardness and low compressibility. In this study, we realise the synthesis of Re<sub>3</sub>C at megabar pressures of 105(3) and 140(5) GPa in laser-heated diamond anvil cells and characterise its structure using synchrotron single-crystal X-ray diffraction. The structure of Re<sub>3</sub>C has the monoclinic space group <i>C</i>2/<i>m</i> and is built of CRe<sub>7</sub> capped octahedra. Our combined ab initio calculations and quantitative topological analysis support experimental structural data and further deepen the understanding of the chemical bonding in the newly synthesized compound.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-024-01300-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142518958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1007/s00269-024-01297-2
A. Kurnosov, G. Criniti, T. Boffa Ballaran, H. Marquardt, D. J. Frost
Single-crystal Brillouin scattering measurements are important for interpreting seismic velocities within the Earth and other planetary interiors. These measurements are rare, however, at temperatures above 1000 K, due to the fact that the transparent samples cannot be heated by common laser heating systems operating at a wavelength on the order of 1 μm. Here we present Brillouin scattering data on pyrope collected at pressures up to 23.8 GPa and temperatures between 850 and 1900 K using a novel CO2 laser heating system confined in either a flexible hollow silica waveguide or an articulated arm with mirrors mounted in each junction to direct the laser to the exit point. Pyrope has been chosen because it has been extensively studied at high pressures and moderate temperatures and therefore it is an excellent sample for bench-marking the CO2 laser heating system. The new high-temperature velocity data collected in this study allow the room pressure thermal parameters of pyrope to be constrained more tightly, resulting in values that reproduce the temperature dependence of the unit-cell volume of pyrope measured in recent studies at ambient pressure. Aggregate wave velocities of pyrope calculated along an adiabat using the thermoelastic parameters determined in this study are larger than those obtained using published values, implying that velocities for many mantle components may be underestimated at mantle temperatures because high temperature experimental data are lacking.
单晶布里渊散射测量对于解释地球和其他行星内部的地震速度非常重要。然而,在 1000 K 以上的温度条件下,这种测量非常罕见,原因是波长为 1 μm 的普通激光加热系统无法对透明样品进行加热。在这里,我们展示了在压力高达 23.8 GPa、温度介于 850 至 1900 K 之间的条件下,使用新型 CO2 激光加热系统收集到的焦红的布里渊散射数据,该系统被限制在一个灵活的空心硅波导或一个铰接臂中,铰接臂的每个结点都安装了反射镜,以便将激光引导到出口点。之所以选择焦岩,是因为对它进行了大量的高压和中温研究,因此它是二氧化碳激光加热系统的绝佳样品。本研究中收集的新高温速度数据可以更严格地限制火绳草的室压热参数,从而得出的数值再现了最近的研究中在环境压力下测得的火绳草单位晶胞体积的温度依赖性。利用本研究确定的热弹性参数沿绝热线计算出的辉绿岩总波速大于利用已公布值计算出的波速,这意味着由于缺乏高温实验数据,许多地幔成分在地幔温度下的波速可能被低估了。
{"title":"High pressure and high temperature Brillouin scattering measurements of pyrope single crystals using flexible CO2 laser heating systems","authors":"A. Kurnosov, G. Criniti, T. Boffa Ballaran, H. Marquardt, D. J. Frost","doi":"10.1007/s00269-024-01297-2","DOIUrl":"10.1007/s00269-024-01297-2","url":null,"abstract":"<div><p>Single-crystal Brillouin scattering measurements are important for interpreting seismic velocities within the Earth and other planetary interiors. These measurements are rare, however, at temperatures above 1000 K, due to the fact that the transparent samples cannot be heated by common laser heating systems operating at a wavelength on the order of 1 μm. Here we present Brillouin scattering data on pyrope collected at pressures up to 23.8 GPa and temperatures between 850 and 1900 K using a novel CO<sub>2</sub> laser heating system confined in either a flexible hollow silica waveguide or an articulated arm with mirrors mounted in each junction to direct the laser to the exit point. Pyrope has been chosen because it has been extensively studied at high pressures and moderate temperatures and therefore it is an excellent sample for bench-marking the CO<sub>2</sub> laser heating system. The new high-temperature velocity data collected in this study allow the room pressure thermal parameters of pyrope to be constrained more tightly, resulting in values that reproduce the temperature dependence of the unit-cell volume of pyrope measured in recent studies at ambient pressure. Aggregate wave velocities of pyrope calculated along an adiabat using the thermoelastic parameters determined in this study are larger than those obtained using published values, implying that velocities for many mantle components may be underestimated at mantle temperatures because high temperature experimental data are lacking.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-024-01297-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1007/s00269-024-01298-1
Juraj Majzlan
Scandium (Sc) is a rare element that finds uses in modern technologies. Thermodynamic properties of Sc phases could help in the development of innovative technologies to extract Sc from mining waste. In this work, we investigated the FeOOH–ScOOH solid solution with the goethite structure. The end members and five intermediate compositions were synthesized and characterized. The lattice parameters show that the solid solution is non-ideal, with complex behavior induced by the Fe–Sc substitution. The excess unit-cell volume deviates negatively for the Sc-rich region, and positively for the Fe-rich region from the ideal behavior (Vegard’s law). Enthalpies of dissolution were determined by acid-solution calorimetry in 5 mol(cdot hbox {dm}^{-3}) HCl at T = 343.15 K. Enthalpies of mixing ((Delta _{mix}H)), calculated from the experimental data, are small and positive. The available data allow for fitting the data as (Delta _{mix}H = W x (1-x)), with the mixing parameter (W = 15.2pm)1.0 kJ(cdot hbox {mol}^{-1}). Using (Delta _fG^o) of ScOOH from earlier literature, we calculated a Lippmann diagram that shows that Sc should strongly partition into the aqueous phase upon goethite precipitation. The field observations from lateritic profiles show that Sc is primarily harbored by goethite via adsorption. It seems that under weathering conditions, thermodynamically driven partitioning of (hbox {Sc}^{3+}) into the aqueous phases and its subsequent adsorption onto goethite surfaces controls the mobility of Sc in the weathering profiles.
{"title":"Thermodynamics of the α-FeOOH (goethite)-ScOOH solid solution","authors":"Juraj Majzlan","doi":"10.1007/s00269-024-01298-1","DOIUrl":"10.1007/s00269-024-01298-1","url":null,"abstract":"<div><p>Scandium (Sc) is a rare element that finds uses in modern technologies. Thermodynamic properties of Sc phases could help in the development of innovative technologies to extract Sc from mining waste. In this work, we investigated the FeOOH–ScOOH solid solution with the goethite structure. The end members and five intermediate compositions were synthesized and characterized. The lattice parameters show that the solid solution is non-ideal, with complex behavior induced by the Fe–Sc substitution. The excess unit-cell volume deviates negatively for the Sc-rich region, and positively for the Fe-rich region from the ideal behavior (Vegard’s law). Enthalpies of dissolution were determined by acid-solution calorimetry in 5 mol<span>(cdot hbox {dm}^{-3})</span> HCl at <i>T</i> = 343.15 K. Enthalpies of mixing (<span>(Delta _{mix}H)</span>), calculated from the experimental data, are small and positive. The available data allow for fitting the data as <span>(Delta _{mix}H = W x (1-x))</span>, with the mixing parameter <span>(W = 15.2pm)</span>1.0 kJ<span>(cdot hbox {mol}^{-1})</span>. Using <span>(Delta _fG^o)</span> of ScOOH from earlier literature, we calculated a Lippmann diagram that shows that Sc should strongly partition into the aqueous phase upon goethite precipitation. The field observations from lateritic profiles show that Sc is primarily harbored by goethite <i>via</i> adsorption. It seems that under weathering conditions, thermodynamically driven partitioning of <span>(hbox {Sc}^{3+})</span> into the aqueous phases and its subsequent adsorption onto goethite surfaces controls the mobility of Sc in the weathering profiles.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-024-01298-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142409473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1007/s00269-024-01296-3
Alexandr V. Romanenko, Sergey V. Rashchenko, Andrey V. Korsakov, Alexander G. Sokol
Compressibility and structural evolution of K-cymrite, hexagonal high-pressure KAlSi3O8·H2O, has been studied up to 18 GPa using synchrotron single crystal X-ray diffraction in Ne pressure medium. K-cymrite retains its original symmetry P6/mmm up to a pressure of 7.3 GPa. As the pressure increases from 7.3 to 8.5 GPa, the weak satellite reflections appear on diffraction patterns and remain up to maximum applied pressure of 18 GPa indicating incommensurate modulation. However, main reflections can be still indexed in hexagonal cell and structure successfully solved in initial P6/mmm group. After pressure release, K-cymrite reverts to initial non-modulated single-crystal state. The parameters of third-order Birch-Murnaghan equation of state for K-cymrite are V0 = 190.45(12) ų, K0 = 56.5(7) GPa and K0’ = 3.2(12), with bulk modulus notably deviating from earlier result (K0 = 45(2) GPa and K0’ = 1.3(10)) obtained in vaseline media.
{"title":"High pressure behavior of K-cymrite (KAlSi3O8·H2O) crystal structure","authors":"Alexandr V. Romanenko, Sergey V. Rashchenko, Andrey V. Korsakov, Alexander G. Sokol","doi":"10.1007/s00269-024-01296-3","DOIUrl":"10.1007/s00269-024-01296-3","url":null,"abstract":"<div><p>Compressibility and structural evolution of K-cymrite, hexagonal high-pressure KAlSi<sub>3</sub>O<sub>8</sub>·H<sub>2</sub>O, has been studied up to 18 GPa using synchrotron single crystal X-ray diffraction in Ne pressure medium. K-cymrite retains its original symmetry <i>P</i>6/<i>mmm</i> up to a pressure of 7.3 GPa. As the pressure increases from 7.3 to 8.5 GPa, the weak satellite reflections appear on diffraction patterns and remain up to maximum applied pressure of 18 GPa indicating incommensurate modulation. However, main reflections can be still indexed in hexagonal cell and structure successfully solved in initial <i>P</i>6/<i>mmm</i> group. After pressure release, K-cymrite reverts to initial non-modulated single-crystal state. The parameters of third-order Birch-Murnaghan equation of state for K-cymrite are <i>V</i><sub>0</sub> = 190.45(12) ų, <i>K</i><sub>0</sub> = 56.5(7) GPa and <i>K</i><sub><i>0</i></sub>’ = 3.2(12), with bulk modulus notably deviating from earlier result (<i>K</i><sub>0</sub> = 45(2) GPa and <i>K</i><sub>0</sub>’ = 1.3(10)) obtained in vaseline media.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1007/s00269-024-01295-4
Shuchang Gao, Jinpu Liu, Hang Cheng, Li Zhang, Yanhao Lin, Xiaoguang Li, Xueqing Qin
High-pressure and high-temperature Raman spectroscopic measurements of synthetic liebenbergite and Ni2SiO4 spinel have been conducted up to 22 GPa and 700 ℃, respectively. Isothermal and isobaric mode Grüneisen parameters were calculated based on the observed Raman modes. The intrinsic anharmonicities of liebenbergite and Ni2SiO4 spinel were also evaluated. The changes of the asymmetric SiO4 stretching band of Ni2SiO4 spinel in frequency are irreversible under decompression, indicating a potential pressure-induced modification in the crystal structure at elevated pressures. The values of isothermal mode Grüneisen parameters show that the SiO4 internal vibrations in Ni-rich olivines are more sensitive to the variations of pressure. For spinel-group minerals, the SiO4 internal vibrations can be less sensitive to the pressure change due to nickel incorporation. In contrast, according to the values of isobaric mode Grüneisen parameters, nickel increases the sensitivity of these vibrations to the variations of temperature. In addition, nickel has distinctive effects on the intrinsic anharmonicities of different vibration modes in both olivine and spinel-group minerals, and therefore alter the thermodynamic properties of their crystal structures.
{"title":"Raman spectroscopic study of liebenbergite and Ni2SiO4 spinel at high pressure and high temperature: nickel effects on the vibration properties of olivine and spinel structures","authors":"Shuchang Gao, Jinpu Liu, Hang Cheng, Li Zhang, Yanhao Lin, Xiaoguang Li, Xueqing Qin","doi":"10.1007/s00269-024-01295-4","DOIUrl":"10.1007/s00269-024-01295-4","url":null,"abstract":"<div><p>High-pressure and high-temperature Raman spectroscopic measurements of synthetic liebenbergite and Ni<sub>2</sub>SiO<sub>4</sub> spinel have been conducted up to 22 GPa and 700 ℃, respectively. Isothermal and isobaric mode Grüneisen parameters were calculated based on the observed Raman modes. The intrinsic anharmonicities of liebenbergite and Ni<sub>2</sub>SiO<sub>4</sub> spinel were also evaluated. The changes of the asymmetric SiO<sub>4</sub> stretching band of Ni<sub>2</sub>SiO<sub>4</sub> spinel in frequency are irreversible under decompression, indicating a potential pressure-induced modification in the crystal structure at elevated pressures. The values of isothermal mode Grüneisen parameters show that the SiO<sub>4</sub> internal vibrations in Ni-rich olivines are more sensitive to the variations of pressure. For spinel-group minerals, the SiO<sub>4</sub> internal vibrations can be less sensitive to the pressure change due to nickel incorporation. In contrast, according to the values of isobaric mode Grüneisen parameters, nickel increases the sensitivity of these vibrations to the variations of temperature. In addition, nickel has distinctive effects on the intrinsic anharmonicities of different vibration modes in both olivine and spinel-group minerals, and therefore alter the thermodynamic properties of their crystal structures.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1007/s00269-024-01287-4
Sha Chen, Udo Becker
Due to experimental challenges and computational complexities, limited research has explored high-temperature and high-pressure conditions on mineral vibrations. This study employs the quasi-harmonic approximation (QHA) and density functional theory (DFT) to investigate the impact of temperature and pressure on the structural properties and infrared and Raman vibrational modes of forsterite. The computational process involves determining lattice parameters, optimizing the internal crystal structure, and calculating IR and Raman spectra at various temperature and pressure values, both separately and combined. Results highlight significant anisotropy in forsterite, with the b-axis being most sensitive to temperature and pressure, followed by the c-axis, while the a-axis exhibits greater stiffness. The positions of vibrational modes typically shift to higher frequencies with increasing pressure (average shift of 2.70 ± 1.30 cm−1/GPa) or to lower frequencies with increasing temperature (average shift of − 0.017 ± 0.018 cm−1/K). Modes associated with SiO4 stretching and bending are less affected by temperature or pressure than translational and rotational modes. A brief investigation into isotope and chemical substitution, as well as cation distribution, in the solid solution (Mg, Fe)2SiO4 reveals lower wavenumbers in fayalite modes compared to forsterite modes, attributed to the heavier Fe mass and larger cell parameters. This study establishes a methodology for computing vibrational frequencies under simultaneous temperature and pressure and emphasizes the significant impact of various factors on vibrational modes. Caution is advised when using vibrational modes for identifying compositions within solid solutions.
由于实验挑战和计算复杂性,探索高温高压条件下矿物振动的研究十分有限。本研究采用准谐波近似(QHA)和密度泛函理论(DFT)来研究温度和压力对绿柱石结构特性以及红外和拉曼振动模式的影响。计算过程包括确定晶格参数、优化内部晶体结构,以及在不同温度和压力值下分别和合并计算红外光谱和拉曼光谱。结果表明,绿柱石具有明显的各向异性,其中 b 轴对温度和压力最为敏感,其次是 c 轴,而 a 轴则表现出更大的刚性。振动模式的位置通常会随着压力的增加而向高频移动(平均移动量为 2.70 ± 1.30 cm-1/GPa),或随着温度的增加而向低频移动(平均移动量为 - 0.017 ± 0.018 cm-1/K)。与平移和旋转模式相比,与 SiO4 拉伸和弯曲相关的模式受温度或压力的影响较小。对固溶体 (Mg,Fe)2SiO4 中同位素和化学取代以及阳离子分布的简要调查显示,与绿柱石模式相比,辉绿岩模式的文数较低,这归因于较重的铁质量和较大的晶胞参数。这项研究确立了在温度和压力同时作用下计算振动频率的方法,并强调了各种因素对振动模式的重要影响。建议在使用振动模式确定固体溶液中的成分时要谨慎。
{"title":"Temperature and pressure effects on the structural and vibrational properties of forsterite from density functional theory studies","authors":"Sha Chen, Udo Becker","doi":"10.1007/s00269-024-01287-4","DOIUrl":"10.1007/s00269-024-01287-4","url":null,"abstract":"<div><p>Due to experimental challenges and computational complexities, limited research has explored high-temperature and high-pressure conditions on mineral vibrations. This study employs the quasi-harmonic approximation (QHA) and density functional theory (DFT) to investigate the impact of temperature and pressure on the structural properties and infrared and Raman vibrational modes of forsterite. The computational process involves determining lattice parameters, optimizing the internal crystal structure, and calculating IR and Raman spectra at various temperature and pressure values, both separately and combined. Results highlight significant anisotropy in forsterite, with the b-axis being most sensitive to temperature and pressure, followed by the c-axis, while the a-axis exhibits greater stiffness. The positions of vibrational modes typically shift to higher frequencies with increasing pressure (average shift of 2.70 ± 1.30 cm<sup>−1</sup>/GPa) or to lower frequencies with increasing temperature (average shift of − 0.017 ± 0.018 cm<sup>−1</sup>/K). Modes associated with SiO<sub>4</sub> stretching and bending are less affected by temperature or pressure than translational and rotational modes. A brief investigation into isotope and chemical substitution, as well as cation distribution, in the solid solution (Mg, Fe)<sub>2</sub>SiO<sub>4</sub> reveals lower wavenumbers in fayalite modes compared to forsterite modes, attributed to the heavier Fe mass and larger cell parameters. This study establishes a methodology for computing vibrational frequencies under simultaneous temperature and pressure and emphasizes the significant impact of various factors on vibrational modes. Caution is advised when using vibrational modes for identifying compositions within solid solutions.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141929260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-05DOI: 10.1007/s00269-024-01293-6
Yohan Park, Tatsuya Wakamatsu, Shintaro Azuma, Yu Nishihara, Kenji Ohta
Studying the anisotropic physical properties of hexagonal closed-packed (hcp) iron is essential for understanding the properties of the Earth’s inner core related to the preferred orientation of the inner core materials suggested by seismic observations. Investigating the anisotropic physical properties of hcp iron requires (1) the synthesis of hcp iron samples that exhibit several distinctive types of strong lattice preferred orientation (LPO) and (2) the quantitative LPO analysis of the samples. Here, we report the distinctive LPO of hcp iron produced from single-crystal body-centered cubic (bcc) iron compressed along three different crystallographic orientations ([100], [110], and [111]) in a diamond anvil cell based on synchrotron multiangle X-ray diffraction measurements up to 80 GPa and 300 K. The orientation relationships between hcp iron and bcc iron are consistent with the Burgers orientation relationship with variant selection. We show that the present method is a way to synthesize hcp iron with strong and characteristic LPO, which is beneficial for experimentally evaluating the anisotropic physical properties of hcp iron.
{"title":"Characterization of the lattice preferred orientation of hcp iron transformed from the single-crystal bcc phase in situ at high pressures up to 80 GPa","authors":"Yohan Park, Tatsuya Wakamatsu, Shintaro Azuma, Yu Nishihara, Kenji Ohta","doi":"10.1007/s00269-024-01293-6","DOIUrl":"10.1007/s00269-024-01293-6","url":null,"abstract":"<div><p>Studying the anisotropic physical properties of hexagonal closed-packed (hcp) iron is essential for understanding the properties of the Earth’s inner core related to the preferred orientation of the inner core materials suggested by seismic observations. Investigating the anisotropic physical properties of hcp iron requires (1) the synthesis of hcp iron samples that exhibit several distinctive types of strong lattice preferred orientation (LPO) and (2) the quantitative LPO analysis of the samples. Here, we report the distinctive LPO of hcp iron produced from single-crystal body-centered cubic (bcc) iron compressed along three different crystallographic orientations ([100], [110], and [111]) in a diamond anvil cell based on synchrotron multiangle X-ray diffraction measurements up to 80 GPa and 300 K. The orientation relationships between hcp iron and bcc iron are consistent with the Burgers orientation relationship with variant selection. We show that the present method is a way to synthesize hcp iron with strong and characteristic LPO, which is beneficial for experimentally evaluating the anisotropic physical properties of hcp iron.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-024-01293-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-05DOI: 10.1007/s00269-024-01286-5
Paul F. Schofield, Andrew J. Berry, Patricia M. Doyle, Kevin S. Knight
CaAl12O19, which can incorporate Ti as both Ti3+ and Ti4+ (charge coupled substitution with Mg2+), is one of the first minerals to condense from a gas of solar composition and is used as a ceramic. It is variously known as hibonite, calcium hexaluminate (CaO.6Al2O3), and CA6. The lattice parameters and unit cell volumes of Ti-substituted hibonite (P63/mmc) with the formulae CaAl11.8Ti3+0.2O19 and CaAl9.8Ti3+0.54Mg0.83Ti4+0.83O19 were determined as a function of temperature from ~ 10 to 275 K by neutron powder diffraction. The thermal expansion is highly anisotropic with the expansion in c a factor of ~ 5 greater than that in a. The change in a is approximately equal for the two compounds whereas the change in c is almost 50% larger for CaAl11.8Ti3+0.2O19. CaAl11.8Ti3+0.2O19 also exhibits negative thermal expansion between 10 and 70 K. The change in unit cell volume with temperature of both compositions is well described by a two term Einstein expression. The large change in c is consistent with substitution of Ti onto the M2 and M4 sites of the R-block structural unit.
CaAl12O19 能以 Ti3+ 和 Ti4+ 的形式结合 Ti(与 Mg2+ 电荷耦合置换),是最早从太阳成分气体中凝结出来的矿物之一,可用作陶瓷。它有不同的名称,如希波石、六铝酸钙(CaO.6Al2O3)和 CA6。通过中子粉末衍射法测定了 CaAl11.8Ti3+0.2O19 和 CaAl9.8Ti3+0.54Mg0.83Ti4+0.83O19 式中 Ti 取代的希波石(P63/mmc)的晶格参数和单胞体积与 ~ 10 至 275 K 温度的函数关系。两种化合物的 a 变化大致相等,而 CaAl11.8Ti3+0.2O19 的 c 变化几乎大 50%。CaAl11.8Ti3+0.2O19 在 10 至 70 K 之间也表现出负热膨胀。两种成分的单位晶胞体积随温度的变化可以用爱因斯坦的两式表达式很好地描述。c 的巨大变化与 Ti 被置换到 R 块结构单元的 M2 和 M4 位点是一致的。
{"title":"The thermal expansion of Ti-substituted CaAl12O19","authors":"Paul F. Schofield, Andrew J. Berry, Patricia M. Doyle, Kevin S. Knight","doi":"10.1007/s00269-024-01286-5","DOIUrl":"10.1007/s00269-024-01286-5","url":null,"abstract":"<div><p>CaAl<sub>12</sub>O<sub>19</sub>, which can incorporate Ti as both Ti<sup>3+</sup> and Ti<sup>4+</sup> (charge coupled substitution with Mg<sup>2+</sup>), is one of the first minerals to condense from a gas of solar composition and is used as a ceramic. It is variously known as hibonite, calcium hexaluminate (CaO.6Al<sub>2</sub>O<sub>3</sub>), and CA<sub>6</sub>. The lattice parameters and unit cell volumes of Ti-substituted hibonite (<i>P</i>6<sub>3</sub>/<i>mmc</i>) with the formulae CaAl<sub>11.8</sub>Ti<sup>3+</sup><sub>0.2</sub>O<sub>19</sub> and CaAl<sub>9.8</sub>Ti<sup>3+</sup><sub>0.54</sub>Mg<sub>0.83</sub>Ti<sup>4+</sup><sub>0.83</sub>O<sub>19</sub> were determined as a function of temperature from ~ 10 to 275 K by neutron powder diffraction. The thermal expansion is highly anisotropic with the expansion in <i>c</i> a factor of ~ 5 greater than that in <i>a</i>. The change in <i>a</i> is approximately equal for the two compounds whereas the change in <i>c</i> is almost 50% larger for CaAl<sub>11.8</sub>Ti<sup>3+</sup><sub>0.2</sub>O<sub>19</sub>. CaAl<sub>11.8</sub>Ti<sup>3+</sup><sub>0.2</sub>O<sub>19</sub> also exhibits negative thermal expansion between 10 and 70 K. The change in unit cell volume with temperature of both compositions is well described by a two term Einstein expression. The large change in <i>c</i> is consistent with substitution of Ti onto the M2 and M4 sites of the R-block structural unit.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-024-01286-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141944977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-05DOI: 10.1007/s00269-024-01294-5
Miki Tasaka, Maya Iwago
Enstatite (Mg2Si2O6) is a member of the pyroxene group and an important mineral in the lower crust and upper mantle. Enstatite has three phases at ambient pressure: protoenstatite, orthoenstatite, and clinoenstatite. Previously, the polymorphic transformation of pyroxene has been characterized using bulk techniques such as X-ray diffraction of powders. Given that rocks are crystal aggregates, it is important to use aggregates to understand phase transformations. We therefore conducted grain growth and deformation experiments using aggregates of enstatite to investigate phase transformations. Grain growth experiments were conducted at temperatures (T) of 1345 and 1360 °C under a vacuum of ≈ 10 Pa using an alumina tube furnace. Deformation experiments were conducted at T = 1310 °C and room pressure, a strain rate of ≈ 10–4 s–1, and a resulting stress of ≈ 150 MPa. The samples were analyzed using a scanning electron microscope, electron backscatter diffraction (EBSD), and X-ray diffraction. The results indicate that the grain size affects the transformation from protoenstatite to clinoenstatite, whereas deformation by diffusion creep does not. The EBSD analyses show that the volume fraction of clinoenstatite increases with increasing grain size. The samples underwent diffusion creep during the deformation experiments, and there were no distinct microstructural differences between deformed and undeformed samples. The EBSD analyses show that the transformed clinoenstatite has a characteristic twin structure with a misorientation angle of 180° and a rotation axis of [100] or [001]. Grain sizes become smaller during the phase transformation, even if the mechanism can be characterized as a second-order transformation.
黝帘石(Mg2Si2O6)是辉石类的一种,也是下地壳和上地幔中的一种重要矿物。在常压下,恩氏闪长岩有三相:原恩氏闪长岩、正恩氏闪长岩和克利诺恩氏闪长岩。以前,人们使用粉末的 X 射线衍射等大块技术来描述辉石的多晶体转变。鉴于岩石是晶体聚集体,利用聚集体来了解相变非常重要。因此,我们利用辉石聚集体进行了晶粒生长和变形实验,以研究相变。晶粒生长实验是在 1345 和 1360 °C 的温度(T)下,利用氧化铝管式炉在≈ 10 Pa 的真空条件下进行的。变形实验是在 T = 1310 °C 和室压下进行的,应变速率为 ≈ 10-4 s-1,产生的应力为 ≈ 150 MPa。使用扫描电子显微镜、电子反向散射衍射(EBSD)和 X 射线衍射对样品进行了分析。结果表明,晶粒尺寸会影响原芒硝向克氏芒硝的转变,而扩散蠕变变形则不会。EBSD 分析表明,随着晶粒尺寸的增大,闪长岩的体积分数也随之增大。样品在变形实验过程中发生了扩散蠕变,变形样品和未变形样品之间没有明显的微观结构差异。EBSD 分析表明,转变后的闪长岩具有特征性的孪晶结构,错向角为 180°,旋转轴为 [100] 或 [001]。在相变过程中,晶粒尺寸变小,即使其机理可定性为二阶转变。
{"title":"Influence of grain size and plastic deformation on the phase transformation of enstatite: insights from microstructures produced during the back-transformation of protoenstatite to clinoenstatite","authors":"Miki Tasaka, Maya Iwago","doi":"10.1007/s00269-024-01294-5","DOIUrl":"10.1007/s00269-024-01294-5","url":null,"abstract":"<div><p>Enstatite (Mg<sub>2</sub>Si<sub>2</sub>O<sub>6</sub>) is a member of the pyroxene group and an important mineral in the lower crust and upper mantle. Enstatite has three phases at ambient pressure: protoenstatite, orthoenstatite, and clinoenstatite. Previously, the polymorphic transformation of pyroxene has been characterized using bulk techniques such as X-ray diffraction of powders. Given that rocks are crystal aggregates, it is important to use aggregates to understand phase transformations. We therefore conducted grain growth and deformation experiments using aggregates of enstatite to investigate phase transformations. Grain growth experiments were conducted at temperatures (<i>T</i>) of 1345 and 1360 °C under a vacuum of ≈ 10 Pa using an alumina tube furnace. Deformation experiments were conducted at <i>T</i> = 1310 °C and room pressure, a strain rate of ≈ 10<sup>–4</sup> s<sup>–1</sup>, and a resulting stress of ≈ 150 MPa. The samples were analyzed using a scanning electron microscope, electron backscatter diffraction (EBSD), and X-ray diffraction. The results indicate that the grain size affects the transformation from protoenstatite to clinoenstatite, whereas deformation by diffusion creep does not. The EBSD analyses show that the volume fraction of clinoenstatite increases with increasing grain size. The samples underwent diffusion creep during the deformation experiments, and there were no distinct microstructural differences between deformed and undeformed samples. The EBSD analyses show that the transformed clinoenstatite has a characteristic twin structure with a misorientation angle of 180° and a rotation axis of [100] or [001]. Grain sizes become smaller during the phase transformation, even if the mechanism can be characterized as a second-order transformation.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-024-01294-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}