Pub Date : 2024-11-12DOI: 10.1021/acs.chemmater.4c02148
Arjun Nain, Lukas Millahn, Markus Gebauer, Linda Schmidt, Holger Kohlmann
Metal hydrides are interesting hosts for activator ions, as they provide opportunities for the tuning of emission wavelengths in luminescent materials. The strong nephelauxetic effect of the hydride ion lowers the barycenter of the d levels and thus also the energy difference from the electronic ground state. General rules on this influence are lacking, however, due to the multitude of variables. Alkaline earth metal hydride halogenides MHX (M = Ca, Sr, Ba; X = Cl, Br, I) are ideally suited for examining the influence of crystal chemical parameters on luminescence properties because they crystallize isotypically in the tetragonal PbFCl type, a relatively simple crystal structure. MHX and Eu(II)-activated samples M0.99Eu0.01HX were synthesized by solid-state reactions and structurally characterized by X-ray and neutron powder diffraction, providing evidence of hydrogen positions. Refined crystal structure data for all nine compounds allow for elucidation of detailed crystal chemical systematics. From BaHCl to CaHI, the coordination of the cations changes from nine to eight, the crystal structure acquires a more pronounced layer character, and the bonding properties show a decreasing ionicity. These changes are also reflected in the luminescence spectra. For a given M, increasing the size of X has almost no influence on M–H distances but increases the emission wavelength considerably. The increasing nephelauxetic effect of halogen X is the most likely cause. Increasing the size of M for a constant X moderately increases M–H distances but strongly decreases the emission wavelength. Eu(II) luminescence in metal hydrides thus seems to be dominated by the M–H distances. The nephelauxetic effect of the halogen atoms is a secondary effect. Combining these effects with partial substitution of fluorine for hydrogen or one M for another offers ample opportunities for fine-tuning the luminescence properties of Eu(II) in metal hydride host compounds.
金属氢化物是活化剂离子的有趣宿主,因为它们为调整发光材料的发射波长提供了机会。氢化物离子的强新负电效应降低了 d 级的原心,从而也降低了与电子基态的能量差。然而,由于变量众多,目前还没有关于这种影响的一般规则。碱土金属氢化物卤化物 MHX(M = Ca、Sr、Ba;X = Cl、Br、I)非常适合研究晶体化学参数对发光特性的影响,因为它们的结晶类型为四方 PbFCl 型,晶体结构相对简单。通过固态反应合成了 MHX 和 Eu(II)-activated 样品 M0.99Eu0.01HX,并通过 X 射线和中子粉末衍射进行了结构表征,提供了氢位置的证据。所有九种化合物的精制晶体结构数据有助于阐明详细的晶体化学系统学。从 BaHCl 到 CaHI,阳离子的配位从 9 个变为 8 个,晶体结构具有更明显的层状特征,键合性质显示出离子性的下降。这些变化也反映在发光光谱中。对于给定的 M,X 的增大对 M-H 间距几乎没有影响,但会大大增加发射波长。最可能的原因是卤素 X 的霓虹灯效应不断增强。在 X 不变的情况下,增大 M 的大小会适度地增加 M-H 间距,但会强烈地减小发射波长。因此,Eu(II)在金属氢化物中的发光似乎主要受 M-H 间距的影响。卤素原子的氖光效应是次要效应。将这些效应与部分氟取代氢或一种 M 取代另一种 M 结合起来,为微调 Eu(II) 在金属氢化物宿主化合物中的发光特性提供了大量机会。
{"title":"Crystal Chemical Parameters for the Eu(II) Luminescence in Solid-State Metal Hydrides","authors":"Arjun Nain, Lukas Millahn, Markus Gebauer, Linda Schmidt, Holger Kohlmann","doi":"10.1021/acs.chemmater.4c02148","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02148","url":null,"abstract":"Metal hydrides are interesting hosts for activator ions, as they provide opportunities for the tuning of emission wavelengths in luminescent materials. The strong nephelauxetic effect of the hydride ion lowers the barycenter of the d levels and thus also the energy difference from the electronic ground state. General rules on this influence are lacking, however, due to the multitude of variables. Alkaline earth metal hydride halogenides <i>M</i>H<i>X</i> (<i>M</i> = Ca, Sr, Ba; <i>X</i> = Cl, Br, I) are ideally suited for examining the influence of crystal chemical parameters on luminescence properties because they crystallize isotypically in the tetragonal PbFCl type, a relatively simple crystal structure. <i>M</i>H<i>X</i> and Eu(II)-activated samples <i>M</i><sub>0.99</sub>Eu<sub>0.01</sub>H<i>X</i> were synthesized by solid-state reactions and structurally characterized by X-ray and neutron powder diffraction, providing evidence of hydrogen positions. Refined crystal structure data for all nine compounds allow for elucidation of detailed crystal chemical systematics. From BaHCl to CaHI, the coordination of the cations changes from nine to eight, the crystal structure acquires a more pronounced layer character, and the bonding properties show a decreasing ionicity. These changes are also reflected in the luminescence spectra. For a given <i>M</i>, increasing the size of <i>X</i> has almost no influence on <i>M</i>–H distances but increases the emission wavelength considerably. The increasing nephelauxetic effect of halogen <i>X</i> is the most likely cause. Increasing the size of <i>M</i> for a constant <i>X</i> moderately increases <i>M</i>–H distances but strongly decreases the emission wavelength. Eu(II) luminescence in metal hydrides thus seems to be dominated by the <i>M</i>–H distances. The nephelauxetic effect of the halogen atoms is a secondary effect. Combining these effects with partial substitution of fluorine for hydrogen or one <i>M</i> for another offers ample opportunities for fine-tuning the luminescence properties of Eu(II) in metal hydride host compounds.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":8.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142599722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-11DOI: 10.1021/acs.chemmater.4c01879
Mu Geun Son, Hyeonji Shin, Hoje Chun, Joonhee Kang
With the growing demand for high-capacity rechargeable batteries, continuous advancements in cathode materials are imperative. Among the candidate materials, Li-excess Mn-rich (LMR) cathodes, known for their superior capacity compared to traditional cathodes, are gaining attention for commercialization. However, Li2MnO3, predominantly used in LMR cathodes, undergoes structural degradation in the voltage plateau region, and its atomic-level mechanisms have not yet been precisely elucidated. Herein, we use first-principles density functional theory calculations to investigate the process of structural change and redox mechanisms of Li2MnO3 induced by local strain. Our studies suggest that local intrinsic strain significantly influences changes in redox mechanisms, Mn migration, and the formation of O–O dimers. Furthermore, the process of structural collapse due to strain was further confirmed through ab initio molecular dynamics calculations. As a final step, we observed the collapse process until all of the Li ions were completely removed from the structure. Our results, considering the effects of local strain, integrate existing degradation mechanisms of Li2MnO3 and provide advanced understanding and new insights for its improvement.
{"title":"Unveiling the Local Strain-Induced Structural Degradation Mechanisms in Li Excess Manganese Cathodes","authors":"Mu Geun Son, Hyeonji Shin, Hoje Chun, Joonhee Kang","doi":"10.1021/acs.chemmater.4c01879","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c01879","url":null,"abstract":"With the growing demand for high-capacity rechargeable batteries, continuous advancements in cathode materials are imperative. Among the candidate materials, Li-excess Mn-rich (LMR) cathodes, known for their superior capacity compared to traditional cathodes, are gaining attention for commercialization. However, Li<sub>2</sub>MnO<sub>3</sub>, predominantly used in LMR cathodes, undergoes structural degradation in the voltage plateau region, and its atomic-level mechanisms have not yet been precisely elucidated. Herein, we use first-principles density functional theory calculations to investigate the process of structural change and redox mechanisms of Li<sub>2</sub>MnO<sub>3</sub> induced by local strain. Our studies suggest that local intrinsic strain significantly influences changes in redox mechanisms, Mn migration, and the formation of O–O dimers. Furthermore, the process of structural collapse due to strain was further confirmed through ab initio molecular dynamics calculations. As a final step, we observed the collapse process until all of the Li ions were completely removed from the structure. Our results, considering the effects of local strain, integrate existing degradation mechanisms of Li<sub>2</sub>MnO<sub>3</sub> and provide advanced understanding and new insights for its improvement.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":8.6,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-11DOI: 10.1021/acs.chemmater.4c01821
Chaitali Sow, Gangaiah Mettela, Suchithra Puliyassery, Giridhar U. Kulkarni
Identification of the crystal phase domain in a given crystallite requires high-resolution electron microscopy and selected area diffraction techniques. However, it is an immense challenge to prepare the samples and identify the polymorphic domains in a crystallite, specifically when the size of the domains is in the μm regime. Here, the well-known Cu electroless process has been used to map the fcc lattice domains from a group of mixed phases in Au crystallites. The Cu growth was selective on the fcc domains, while the noncubic lattice regions (i.e., body-centered orthorhombic and body-centered tetragonal, together called bc(o,t) lattices) remained free of Cu. In spite of the similar lattice mismatches, the Cu deposition is mainly governed by the isotropic geometry of the fcc surfaces, irrespective of the crystal morphology. The obtained Au–Cu structures have served as seeds to grow bimetals (Au–Ag, Au–Pd, and Au–Pt) and metal–semiconductors/heterostructures (Au–CuS and Au–Cu2O) with anisotropic geometry.
{"title":"Deciphering NonCubic Phases in Au Microcrystallites via Under Potential Cu Deposition and Selective Growth of Noble Metal and Sulfide Overlayers","authors":"Chaitali Sow, Gangaiah Mettela, Suchithra Puliyassery, Giridhar U. Kulkarni","doi":"10.1021/acs.chemmater.4c01821","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c01821","url":null,"abstract":"Identification of the crystal phase domain in a given crystallite requires high-resolution electron microscopy and selected area diffraction techniques. However, it is an immense challenge to prepare the samples and identify the polymorphic domains in a crystallite, specifically when the size of the domains is in the μm regime. Here, the well-known Cu electroless process has been used to map the <i>fcc</i> lattice domains from a group of mixed phases in Au crystallites. The Cu growth was selective on the <i>fcc</i> domains, while the <i>noncubic</i> lattice regions (i.e., body-centered orthorhombic and body-centered tetragonal, together called <i>bc(o,t)</i> lattices) remained free of Cu. In spite of the similar lattice mismatches, the Cu deposition is mainly governed by the isotropic geometry of the <i>fcc</i> surfaces, irrespective of the crystal morphology. The obtained Au–Cu structures have served as seeds to grow bimetals (Au–Ag, Au–Pd, and Au–Pt) and metal–semiconductors/heterostructures (Au–CuS and Au–Cu<sub>2</sub>O) with anisotropic geometry.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":8.6,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Achieving efficient selective visible light-induced oxidation of benzyl C(sp3)–H to more valuable double-bonded compounds holds significant promise for organic synthesis. In this work, we fabricated an example of Ir metalloligand-modified POMOF crystalline material, CI-SiW, which is noteworthy as the first example of POM immobilized in a metalloligand-modified MOF via coordination bonding. Under the excitation of visible light (10 W, λ = 410 nm), CI-SiW can catalyze the efficient oxidation of benzyl C(sp3)–H of isochromane with a turnover number and turnover frequency of 954 and 1740 h–1, respectively. Excitingly, CI-SiW displays the best TOF compared with previous photocatalysts under the same conditions, realizing the maximum yield with the minimum amount of photocatalyst. Furthermore, CI-SiW had good cyclic and structural stability, and a 90.4% yield was still obtained after three reaction cycles.
{"title":"Enhanced C(sp3)–H Selective Oxidation Using Efficient Polyoxometalate-Based Metal–Organic Framework Photocatalysts Synergized with Ir Metalloligands and Polyoxometalates","authors":"Jing Wang, Luoning Li, Yanan Liu, Zelong Yuan, Pengtao Ma, Jingping Wang, Jingyang Niu","doi":"10.1021/acs.chemmater.4c02040","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02040","url":null,"abstract":"Achieving efficient selective visible light-induced oxidation of benzyl C(sp<sup>3</sup>)–H to more valuable double-bonded compounds holds significant promise for organic synthesis. In this work, we fabricated an example of Ir metalloligand-modified POMOF crystalline material, <b>CI-SiW</b>, which is noteworthy as the first example of POM immobilized in a metalloligand-modified MOF via coordination bonding. Under the excitation of visible light (10 W, λ = 410 nm), <b>CI-SiW</b> can catalyze the efficient oxidation of benzyl C(sp<sup>3</sup>)–H of isochromane with a turnover number and turnover frequency of 954 and 1740 h<sup>–1</sup>, respectively. Excitingly, <b>CI-SiW</b> displays the best TOF compared with previous photocatalysts under the same conditions, realizing the maximum yield with the minimum amount of photocatalyst. Furthermore, <b>CI-SiW</b> had good cyclic and structural stability, and a 90.4% yield was still obtained after three reaction cycles.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":8.6,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1021/acs.chemmater.4c01446
Prabhanjan Pradhan, Prabhat Kumar, Ravi Kumar Bandaru, Rambabu Dandela, Rupak Banerjee, Biplab K. Patra
Organic–inorganic halide perovskites (OIHPs) have attracted tremendous attention from researchers because of their diverse applications in optoelectronics, sensing, catalysis, memory, photodetectors, and medical diagnostics. The presence of inherent ferroelectricity in these perovskite materials facilitates the separation of photogenerated electron–hole pairs. Here, we report a large phosphonium cation-based methyl triphenyl phosphonium lead bromide (MTPLB) perovskite-like semiconductor with a direct band gap of 3.49 eV, which shows ferroelectricity in both nanoscale and bulk at room temperature. The material exhibits a phase transition temperature of 477 K, a polarization saturation of 0.26 μC/cm2, and a d33 of 5.2 pC/N. MTPLB displays a robust piezoelectric response, as confirmed via advanced piezoresponse force microscopy (PFM). Further, we have fabricated nanogenerator devices with varying ratios of MTPLB and poly(vinylidene fluoride) (PVDF) composites for mechanical and biomechanical energy harvesting. We report an enhanced piezoresponse in all devices with the best response in the device with a 2% MTPLB loading in the PVDF matrix due to the triggering of the electroactive phases in PVDF. The improved output response, operational durability, and flexibility of the composite-based devices underscore their potential for advanced technological applications in electronics, actuators, sensors, and mechanical energy-harvesting processes.
{"title":"Phosphonium Cation-Based Ferroelectric 1D Halide Perovskite-Like Semiconductor for Mechanical Energy Harvesting","authors":"Prabhanjan Pradhan, Prabhat Kumar, Ravi Kumar Bandaru, Rambabu Dandela, Rupak Banerjee, Biplab K. Patra","doi":"10.1021/acs.chemmater.4c01446","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c01446","url":null,"abstract":"Organic–inorganic halide perovskites (OIHPs) have attracted tremendous attention from researchers because of their diverse applications in optoelectronics, sensing, catalysis, memory, photodetectors, and medical diagnostics. The presence of inherent ferroelectricity in these perovskite materials facilitates the separation of photogenerated electron–hole pairs. Here, we report a large phosphonium cation-based methyl triphenyl phosphonium lead bromide (MTPLB) perovskite-like semiconductor with a direct band gap of 3.49 eV, which shows ferroelectricity in both nanoscale and bulk at room temperature. The material exhibits a phase transition temperature of 477 K, a polarization saturation of 0.26 μC/cm<sup>2</sup>, and a <i>d</i><sub>33</sub> of 5.2 pC/N. MTPLB displays a robust piezoelectric response, as confirmed via advanced piezoresponse force microscopy (PFM). Further, we have fabricated nanogenerator devices with varying ratios of MTPLB and poly(vinylidene fluoride) (PVDF) composites for mechanical and biomechanical energy harvesting. We report an enhanced piezoresponse in all devices with the best response in the device with a 2% MTPLB loading in the PVDF matrix due to the triggering of the electroactive phases in PVDF. The improved output response, operational durability, and flexibility of the composite-based devices underscore their potential for advanced technological applications in electronics, actuators, sensors, and mechanical energy-harvesting processes.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":8.6,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1021/acs.chemmater.4c02003
Harry M. Schrickx, Caleb Moore, Abdullah Al Shafe, Alireza Samadani, Nrup Balar, Doan Vu, Jeromy J. Rech, Wei You, Brendan T. O’Connor
The thermomechanical properties of conjugated polymers (CPs) play a crucial role in device morphological, mechanical, and thermal stability and influence device processing parameters. However, the thermal transition behavior of CPs can be difficult to characterize, particularly as the molecular complexity increases. Here, we introduce a characterization technique that is an effective and sensitive approach to observing and defining thermal transitions in CPs. Our approach combines strain alignment with in situ polarized ultraviolet–visible absorption spectroscopy, which we name AFIPS. By monitoring changes in the absorption spectra and dichroism, we demonstrate the ability to effectively identify and characterize thermal transitions undetected using calorimetry. We use this in situ characterization method along with dynamic mechanical analysis (DMA) to probe the thermal transitions of various CPs, including F8T2, P3HT, PCDTBT, PTB7-Th, PM6, and PBnDT-FTAZ. We show that the measurement has a unique response to glass transitions (Tg), cold crystallization (Tcc), liquid crystal transitions, and melting. In this investigation, we uncover signatures of a Tg in PTB7-Th and a Tcc in PCDTBT. Using the AFIPS technique complements other thermomechanical measurements, such as DMA, while being simple and effective to implement, providing a valuable tool for polymer thin film characterization.
{"title":"Discerning Thermal Transition Behavior of Conjugated Polymers through In Situ Optical Characterization of Oriented Films","authors":"Harry M. Schrickx, Caleb Moore, Abdullah Al Shafe, Alireza Samadani, Nrup Balar, Doan Vu, Jeromy J. Rech, Wei You, Brendan T. O’Connor","doi":"10.1021/acs.chemmater.4c02003","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02003","url":null,"abstract":"The thermomechanical properties of conjugated polymers (CPs) play a crucial role in device morphological, mechanical, and thermal stability and influence device processing parameters. However, the thermal transition behavior of CPs can be difficult to characterize, particularly as the molecular complexity increases. Here, we introduce a characterization technique that is an effective and sensitive approach to observing and defining thermal transitions in CPs. Our approach combines strain alignment with in situ polarized ultraviolet–visible absorption spectroscopy, which we name AFIPS. By monitoring changes in the absorption spectra and dichroism, we demonstrate the ability to effectively identify and characterize thermal transitions undetected using calorimetry. We use this in situ characterization method along with dynamic mechanical analysis (DMA) to probe the thermal transitions of various CPs, including F8T2, P3HT, PCDTBT, PTB7-Th, PM6, and PBnDT-FTAZ. We show that the measurement has a unique response to glass transitions (<i>T</i><sub>g</sub>), cold crystallization (<i>T</i><sub>cc</sub>), liquid crystal transitions, and melting. In this investigation, we uncover signatures of a <i>T</i><sub>g</sub> in PTB7-Th and a <i>T</i><sub>cc</sub> in PCDTBT. Using the AFIPS technique complements other thermomechanical measurements, such as DMA, while being simple and effective to implement, providing a valuable tool for polymer thin film characterization.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":8.6,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1021/acs.chemmater.4c01757
Huan Tran, Hieu-Chi Dam, Christopher Kuenneth, Vu Ngoc Tuoc, Hiori Kino
The past two decades have witnessed a tremendous number of computational predictions of hydride-based (phonon-mediated) superconductors, mostly at extremely high pressures, i.e., hundreds of gigapascals. These discoveries were strongly driven by Migdal–Éliashberg theory (and its first-principles computational implementations) for electron–phonon interactions, the key concept of phonon-mediated superconductivity. Dozens of predictions were experimentally synthesized and characterized, triggering not only enormous excitement in the community but also some debates. In this work, we review the computationally driven discoveries and the recent developments in the field from various essential aspects, including the theoretically based, computationally based, and, specifically, artificial intelligence/machine learning (AI/ML)-based approaches emerging within the paradigm of materials informatics. While challenges and critical gaps can be found in all of these approaches, AI/ML efforts specifically remain in their infancy for good reasons. However, there are opportunities in which these approaches can be further developed and integrated in concerted efforts, in which AI/ML approaches could play more important roles.
{"title":"Superconductor Discovery in the Emerging Paradigm of Materials Informatics","authors":"Huan Tran, Hieu-Chi Dam, Christopher Kuenneth, Vu Ngoc Tuoc, Hiori Kino","doi":"10.1021/acs.chemmater.4c01757","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c01757","url":null,"abstract":"The past two decades have witnessed a tremendous number of computational predictions of hydride-based (phonon-mediated) superconductors, mostly at extremely high pressures, i.e., hundreds of gigapascals. These discoveries were strongly driven by Migdal–Éliashberg theory (and its first-principles computational implementations) for electron–phonon interactions, the key concept of phonon-mediated superconductivity. Dozens of predictions were experimentally synthesized and characterized, triggering not only enormous excitement in the community but also some debates. In this work, we review the computationally driven discoveries and the recent developments in the field from various essential aspects, including the theoretically based, computationally based, and, specifically, artificial intelligence/machine learning (AI/ML)-based approaches emerging within the paradigm of materials informatics. While challenges and critical gaps can be found in all of these approaches, AI/ML efforts specifically remain in their infancy for good reasons. However, there are opportunities in which these approaches can be further developed and integrated in concerted efforts, in which AI/ML approaches could play more important roles.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":8.6,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1021/acs.chemmater.4c02058
Rouzbeh Aghaei Hakkak, Thomas Schleid
Two new tetrahydrazinium dihalide dodecahydro-closo-dodecaborates (N2H5)4X2[B12H12] (X– = Cl– and Br–) were successfully synthesized via the direct reaction of dihydrazinium dodecahydro-closo-dodecaborate (N2H4)2[B12H12] with hydrazinium halides (N2H5)Cl and (N2H5)Br in aqueous media. The resulting isotypic compounds crystallize monoclinically in the space group P21/c with similar unit-cell parameters (a = 681.98(4) pm, b = 1025.38(6) pm, c = 1325.38(8) pm, and β = 98.393(3)° for the chloride and a = 686.05(4) pm, b = 1032.51(6) pm, c = 1316.04(8), and β = 97.449(3)° for the bromide). Their crystal structure was elucidated using single-crystal X-ray diffraction techniques, unveiling a new unique arrangement for the composition A4B2C (A = hydrazinium, B = halide, and C = dodecahydro-closo-dodecaborate). This distinctive structural configuration sets it apart from compounds exhibiting other A4B2C arrangements, such as the spinel or double-perovskite structure type. In this new structure, the halide anions are coordinated by five hydrazinium cations, creating triangular bipyramidal polyhedra. These are interconnected via edge- and corner-sharing, resulting in the formation of hexagonal tunnels along the [100] direction. Within each of these tunnels, the [B12H12]2– clusters reside centrally located. Differential scanning calorimetry analyses demonstrate that these compounds contain a substantial amount of energy that is released during their thermal decomposition.
{"title":"New Energetic Dodecahydro-closo-Dodecaborates (N2H5)4X2[B12H12] (X = Cl and Br) with a Novel Hexagonal A4B2C Tunnel Structure","authors":"Rouzbeh Aghaei Hakkak, Thomas Schleid","doi":"10.1021/acs.chemmater.4c02058","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02058","url":null,"abstract":"Two new tetrahydrazinium dihalide dodecahydro-<i>closo</i>-dodecaborates (N<sub>2</sub>H<sub>5</sub>)<sub>4</sub><i>X</i><sub>2</sub>[B<sub>12</sub>H<sub>12</sub>] (<i>X</i><sup>–</sup> = Cl<sup>–</sup> and Br<sup>–</sup>) were successfully synthesized via the direct reaction of dihydrazinium dodecahydro-<i>closo</i>-dodecaborate (N<sub>2</sub>H<sub>4</sub>)<sub>2</sub>[B<sub>12</sub>H<sub>12</sub>] with hydrazinium halides (N<sub>2</sub>H<sub>5</sub>)Cl and (N<sub>2</sub>H<sub>5</sub>)Br in aqueous media. The resulting isotypic compounds crystallize monoclinically in the space group <i>P</i>2<sub>1</sub>/<i>c</i> with similar unit-cell parameters (<i>a</i> = 681.98(4) pm, <i>b</i> = 1025.38(6) pm, <i>c</i> = 1325.38(8) pm, and β = 98.393(3)° for the chloride and <i>a</i> = 686.05(4) pm, <i>b</i> = 1032.51(6) pm, <i>c</i> = 1316.04(8), and β = 97.449(3)° for the bromide). Their crystal structure was elucidated using single-crystal X-ray diffraction techniques, unveiling a new unique arrangement for the composition <i>A</i><sub>4</sub><i>B</i><sub>2</sub><i>C</i> (<i>A</i> = hydrazinium, <i>B</i> = halide, and <i>C</i> = dodecahydro-<i>closo</i>-dodecaborate). This distinctive structural configuration sets it apart from compounds exhibiting other <i>A</i><sub>4</sub><i>B</i><sub>2</sub><i>C</i> arrangements, such as the spinel or double-perovskite structure type. In this new structure, the halide anions are coordinated by five hydrazinium cations, creating triangular bipyramidal polyhedra. These are interconnected via edge- and corner-sharing, resulting in the formation of hexagonal tunnels along the [100] direction. Within each of these tunnels, the [B<sub>12</sub>H<sub>12</sub>]<sup>2–</sup> clusters reside centrally located. Differential scanning calorimetry analyses demonstrate that these compounds contain a substantial amount of energy that is released during their thermal decomposition.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":8.6,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1021/acs.chemmater.4c02057
Meng Cao, Jisheng Song, Haonan Ren, Fan Yang, Rong Chen
With the development of integrated circuit miniaturization, the RC delay caused by the interconnect resistance of metal wires and the capacitance of interlayer dielectric materials limits the high integration and miniaturization of electronic devices. As a promising low-k dielectric material, metal–organic frameworks (MOFs) can effectively alleviate this problem. In this work, we report an atomic regulation strategy of ultralow k MIL-53 film, achieved by converting an Al2O3 seed layer deposited via atomic layer deposition (ALD) and subsequently modifying through atomic layer infiltration (ALI). Thanks to the linear relationship between the thickness of the MIL-53 film and the Al2O3 seed layer prepared by ALD, precise nanoscale control of the MIL-53 films was realized. To meet both mechanical and dielectric property requirements, ALI modification is introduced, effectively regulating Young’s modulus and hardness of MIL-53 films from 19.5 and 0.17 GPa to 29.1 and 0.36 GPa, respectively, while the dielectric constant can be tuned from 1.93 to 2.59. The reconciliation of these properties is achieved by regulating the porosity of the MIL-53 framework through the additional Al–O clusters during the ALI. Furthermore, the superhydrophobic properties (140.7°) and the nearly constant dielectric constant after 9 months of aging reflect its potential as a dielectric insulating material. The proposed preparation and modification strategy of MOF films based on atomic regulation has broad potential for application in low-k interconnect integrated circuits.
{"title":"Atomic Regulation of Metal–Organic Framework Thin Film for Low-k Dielectric","authors":"Meng Cao, Jisheng Song, Haonan Ren, Fan Yang, Rong Chen","doi":"10.1021/acs.chemmater.4c02057","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02057","url":null,"abstract":"With the development of integrated circuit miniaturization, the RC delay caused by the interconnect resistance of metal wires and the capacitance of interlayer dielectric materials limits the high integration and miniaturization of electronic devices. As a promising low-<i>k</i> dielectric material, metal–organic frameworks (MOFs) can effectively alleviate this problem. In this work, we report an atomic regulation strategy of ultralow <i>k</i> MIL-53 film, achieved by converting an Al<sub>2</sub>O<sub>3</sub> seed layer deposited via atomic layer deposition (ALD) and subsequently modifying through atomic layer infiltration (ALI). Thanks to the linear relationship between the thickness of the MIL-53 film and the Al<sub>2</sub>O<sub>3</sub> seed layer prepared by ALD, precise nanoscale control of the MIL-53 films was realized. To meet both mechanical and dielectric property requirements, ALI modification is introduced, effectively regulating Young’s modulus and hardness of MIL-53 films from 19.5 and 0.17 GPa to 29.1 and 0.36 GPa, respectively, while the dielectric constant can be tuned from 1.93 to 2.59. The reconciliation of these properties is achieved by regulating the porosity of the MIL-53 framework through the additional Al–O clusters during the ALI. Furthermore, the superhydrophobic properties (140.7°) and the nearly constant dielectric constant after 9 months of aging reflect its potential as a dielectric insulating material. The proposed preparation and modification strategy of MOF films based on atomic regulation has broad potential for application in low-<i>k</i> interconnect integrated circuits.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":8.6,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1021/acs.chemmater.4c01835
Shih-Nan Hsiao, Makoto Sekine, Yuki Iijima, Masaru Hori
Cryogenic atomic layer etching (ALE) represents a promising technique for achieving subnanoscale material removal in semiconductor processes, owing to its unique self-limiting surface-adsorbing reactions. This paper presents a cryogenic ALE method for SiN, utilizing surface modification with a hydrogen fluoride (HF) dose and an Ar etch step for removing the modification layer. The surface reactions and etching mechanism were examined using in situ monitoring techniques, including spectroscopic ellipsometry and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Our observations reveal a self-limiting etching behavior for SiN and a reduction in the etch amount per cycle (EPC) with a decreasing substrate temperature. During the HF dose step, in situ ATR-FTIR spectra indicate the formation of a surface-adsorbed layer containing ammonium fluorosilicate (AFS) on the SiN surface. Subsequently, during the Ar plasma etching step, both the AFS layer and the surface-adsorbed species were removed. At lower substrate temperatures, the stability of the AFS layer and surface-absorbed species increased, resulting in a reduction in EPC. Through the control of Ar ion energy and substrate temperature, the manipulation of EPC ranging from several nanometers to a few angstroms in atomic layer etching is achieved, offering potential utility in nanoscale device applications utilizing silicon nitride.
{"title":"In Situ Monitoring Surface Reactions in Cryogenic Atomic Layer Etching of Silicon Nitride by Alternating Surface Modification with Hydrogen Fluoride Dose and Ar Plasmas","authors":"Shih-Nan Hsiao, Makoto Sekine, Yuki Iijima, Masaru Hori","doi":"10.1021/acs.chemmater.4c01835","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c01835","url":null,"abstract":"Cryogenic atomic layer etching (ALE) represents a promising technique for achieving subnanoscale material removal in semiconductor processes, owing to its unique self-limiting surface-adsorbing reactions. This paper presents a cryogenic ALE method for SiN, utilizing surface modification with a hydrogen fluoride (HF) dose and an Ar etch step for removing the modification layer. The surface reactions and etching mechanism were examined using <i>in situ</i> monitoring techniques, including spectroscopic ellipsometry and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Our observations reveal a self-limiting etching behavior for SiN and a reduction in the etch amount per cycle (EPC) with a decreasing substrate temperature. During the HF dose step, in situ ATR-FTIR spectra indicate the formation of a surface-adsorbed layer containing ammonium fluorosilicate (AFS) on the SiN surface. Subsequently, during the Ar plasma etching step, both the AFS layer and the surface-adsorbed species were removed. At lower substrate temperatures, the stability of the AFS layer and surface-absorbed species increased, resulting in a reduction in EPC. Through the control of Ar ion energy and substrate temperature, the manipulation of EPC ranging from several nanometers to a few angstroms in atomic layer etching is achieved, offering potential utility in nanoscale device applications utilizing silicon nitride.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":8.6,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}