Chinese Journal of Physics最新文献_第6页

Investigation of the Structural, Dielectric, Optical, and Electronic Properties of Hydrothermally Synthesized Bi2Fe4O9 Multiferroic Materials 水热合成Bi2Fe4O9多铁性材料的结构、介电、光学和电子性能研究

IF 4.6 2区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Chinese Journal of Physics

Pub Date : 2026-02-01 Epub Date: 2025-11-29 DOI: 10.1016/j.cjph.2025.11.033

I. Mallek-Zouari , A.E. Maayoufi , R. Bez , A. Kouki , N. Thabet-Mliki

Bi₂Fe₄O₉ (BFO) was synthesized using a hydrothermal method to achieve controlled phase purity and morphology. Rietveld refinement of the X-ray diffraction (XRD) pattern confirmed the formation of a single orthorhombic phase with the Pbam space group. Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) analyses revealed plate-like particles with dimensions ranging from 140 to 170 nm along their edge. The dielectric properties were evaluated by analyzing the frequency dependence of the dielectric constant, loss tangent, and electrical conductivity. The results indicated that the optimization of synthesis parameters significantly enhanced the dielectric response of Bi₂Fe₄O₉, resulting in improved high-frequency performance. The correlation between microstructural characteristics and dielectric properties is discussed, with an emphasis on the roles of grain boundaries, phase purity, and conductivity in determining dielectric behavior. The UV-Vis absorption spectra recorded at room temperature revealed substantial absorption within the ultraviolet range (200–400 nm). Tauc plot analysis yielded an estimated band gap value of approximately 1.97 eV. Density functional theory (DFT) calculations, performed using the generalized gradient approximation (GGA+U) with the Wien2k code, provided insights into the electronic band structure and density of states (DOS). The calculated results are in good agreement with the experimental findings. This study highlights Bi₂Fe₄O₉ as a promising material for advanced dielectric and environmental applications.

采用水热法合成了Bi2Fe4O9 (BFO)，实现了相纯度和形貌的控制。x射线衍射（XRD）图的Rietveld细化证实了与pham空间基团形成的单一正交相。透射电子显微镜（TEM）和高分辨率透射电子显微镜（HRTEM）分析显示，沿边缘的片状颗粒尺寸在140 ~ 170 nm之间。通过分析介电常数、损耗正切和电导率的频率依赖性来评估介电性能。结果表明，优化合成参数可显著提高Bi2Fe4O9的介电响应，从而提高其高频性能。讨论了微观结构特征与介电性能之间的关系，重点讨论了晶界、相纯度和电导率在决定介电性能中的作用。在室温下记录的紫外-可见吸收光谱显示在200-400 nm紫外范围内有大量吸收。Tauc图分析估计带隙值约为1.97 eV。密度泛函理论（DFT）计算，使用广义梯度近似（GGA+U）和Wien2k代码进行，提供了对电子能带结构和态密度（DOS）的见解。计算结果与实验结果吻合较好。这项研究强调了Bi2Fe4O9作为一种有前途的材料用于先进的介电和环境应用。

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引用次数: 0

Fractional mode charges in acoustic non-Hermitian topological Anderson insulator 声学非厄米拓扑安德森绝缘子中的分数模式电荷

IF 4.6 2区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Chinese Journal of Physics

Pub Date : 2026-02-01 Epub Date: 2025-11-26 DOI: 10.1016/j.cjph.2025.11.032

Wenbin Lv , Jinyang He , Han Cao , Chudong Xu , Ming-Hui Lu

The investigation of non-Hermitian topological systems has attracted significant attention across diverse fields, including photonics and acoustics. Recent studies have demonstrated that disorder can induce topological states in otherwise trivial systems, leading to the discovery of Non-Hermitian topological Anderson insulator (NH-TAI). This study explores the effects of non-Hermitian disorder on acoustic systems through numerical simulations and theoretical calculation. Coupled acoustic cavity arrays with non-Hermitian disorder profiles in one- and two-dimensional configurations are investigated. The findings reveal that tuning the disorder strength can induce a transition from a trivial to a nontrivial topological phase. More importantly, by calculating the fractional mode charges through integration of the local density of states (LDOS) within the band gap, it is demonstrated that non-Hermitian disorder alone can induce a topological Anderson phase characterized via fractional mode charges. Additionally, the robustness of the system is confirmed by simulating structural defects. These findings are applicable to other physical platforms, such as optics, and pave a pathway for future research in non-Hermitian acoustics.

对非厄米拓扑系统的研究已经引起了包括光子学和声学在内的各个领域的极大关注。最近的研究表明，无序可以在其他平凡系统中诱导拓扑状态，从而发现了非厄米拓扑安德森绝缘子（NH-TAI）。本文通过数值模拟和理论计算，探讨了非厄米无序对声学系统的影响。研究了具有一维和二维非厄米无序分布的耦合声腔阵列。研究结果表明，调整无序强度可以诱导从平凡到非平凡拓扑阶段的转变。更重要的是，通过积分带隙内的局域态密度（LDOS）计算分数模式电荷，证明了非厄米无序可以单独诱导出以分数模式电荷为特征的拓扑Anderson相。此外，通过对结构缺陷的仿真验证了系统的鲁棒性。这些发现适用于其他物理平台，如光学，并为未来的非厄米声学研究铺平了道路。

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引用次数: 0

The impact of coherence in non-equilibrium reservoirs on the functionality and performance of quantum thermal machines 非平衡储层中相干性对量子热机功能和性能的影响

IF 4.6 2区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Chinese Journal of Physics

Pub Date : 2026-02-01 Epub Date: 2025-12-27 DOI: 10.1016/j.cjph.2025.12.031

Zhi-Chu Chen, Qingyu Cai, Ji-Yong Fu, Zhong-Xiao Man

We investigate the functionality and performance of quantum thermal machines (QTMs) implemented using multipartite open quantum systems coupled to independent non-equilibrium reservoirs. We focus on two distinct types of work in QTMs, namely, the work arising from the coherence of reservoirs and that supplied by an external source. With two- and three-body interactions within the working substance, we demonstrate that QTMs in the presence of reservoir coherence can attain unique operational modes unattainable in purely thermal reservoirs. Furthermore, the QTMs can perform both single tasks driven by multiple inputs and hybrid operations driven by a single input. We define a non-equilibrium free-energy-based efficiency to assess the performance of this class of QTMs. Within specific parameter ranges, reservoir coherence can be harnessed to enhance the efficiency of QTMs. Our findings offer valuable insights for designing QTMs with customized functions and for optimizing their performance by leveraging coherence in non-equilibrium reservoirs.

我们研究了量子热机（QTMs）的功能和性能，量子热机是由耦合到独立非平衡热源的多部开放量子系统实现的。我们专注于QTMs中的两种不同类型的工作，即由储层一致性引起的工作和由外部来源提供的工作。通过工作物质内的二体和三体相互作用，我们证明了在储层相干性存在的情况下，qtm可以获得在纯热储层中无法实现的独特操作模式。此外，qtm既可以执行由多个输入驱动的单一任务，也可以执行由单个输入驱动的混合操作。我们定义了一个非平衡的基于自由能量的效率来评估这类qtm的性能。在特定的参数范围内，可以利用储层相干性来提高qtm的效率。我们的研究结果为设计具有定制功能的qtm提供了有价值的见解，并通过利用非平衡油藏的相干性来优化其性能。

引用次数: 0

Influence of bleb formation on intracranial aneurysm hemodynamics: a patient-specific CFD study 气泡形成对颅内动脉瘤血流动力学的影响：一项针对患者的CFD研究

IF 4.6 2区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Chinese Journal of Physics

Pub Date : 2026-02-01 Epub Date: 2025-12-10 DOI: 10.1016/j.cjph.2025.12.011

Li Song , Peng Du , Erhao Bao

Intracranial aneurysms with secondary bleb formation are considered to have an elevated risk of rupture due to localized geometric and hemodynamic instabilities. In this study, we perform a comparative computational fluid dynamics (CFD) analysis on five patient-specific aneurysm geometries, examining pre- and post-bleb configurations to evaluate hemodynamic changes associated with bleb development. Key metrics including wall shear stress (WSS), sac wall pressure, and intra-aneurysmal velocity were analyzed at peak systolic time points while oscillatory shear index (OSI) is obtained vial whole cardiac cycle. Results indicate that bleb formation introduces localized flow disturbances and hemodynamic variability, with case-dependent effects. Quantitatively, bleb regions exhibited up to a 36% reduction in mean WSS (e.g., Case E: 13.3 Pa → 9.8 Pa) and up to a 4-fold increase in minimum WSS (e.g., Case C: 0.21 Pa → 0.72 Pa in the bleb), reflecting strong spatial heterogeneity in shear loading. Despite these hemodynamic changes, the vessel wall in bleb regions becomes thinner and structurally weaker, reducing its resistance to blood pressure and thereby increasing rupture susceptibility. These findings emphasize the importance of multi-parametric hemodynamic evaluation—particularly WSS magnitude, OSI distribution, and flow patterns—in understanding bleb-induced changes in aneurysm stability. The study underscores the need for individualized risk assessment strategies that go beyond morphological classification alone.

由于局部几何和血流动力学不稳定，颅内动脉瘤伴继发性气泡形成被认为具有较高的破裂风险。在这项研究中，我们对五种患者特定的动脉瘤几何形状进行了比较计算流体动力学（CFD）分析，检查了起泡前和起泡后的配置，以评估与气泡发展相关的血流动力学变化。主要指标包括收缩峰值时的壁剪切应力（WSS）、囊壁压力和动脉瘤内速度，并获得整个心脏周期内的振荡剪切指数（OSI）。结果表明，气泡的形成会引起局部的血流紊乱和血流动力学变异性，并具有病例依赖性。从数量上看，气泡区域的平均WSS减少了36%（例如，病例E: 13.3 Pa→9.8 Pa），最小WSS增加了4倍（例如，病例C: 0.21 Pa→0.72 Pa），反映了剪切载荷的强烈空间异质性。尽管有这些血流动力学变化，但水泡区域的血管壁变薄，结构变弱，降低了其对血压的抵抗力，从而增加了破裂的易感性。这些发现强调了多参数血流动力学评估的重要性，特别是WSS大小、OSI分布和血流模式，以了解气泡引起的动脉瘤稳定性变化。该研究强调需要个性化的风险评估策略，而不仅仅是形态学分类。

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引用次数: 0

Simulation study of reversible random sequential adsorption of lattice animals on a three-dimensional cubic lattice 格子动物在三维立方晶格上可逆随机顺序吸附的模拟研究

IF 4.6 2区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Chinese Journal of Physics

Pub Date : 2026-02-01 Epub Date: 2025-12-11 DOI: 10.1016/j.cjph.2025.12.010

Julija R. Šćepanović , Danica Stojiljković , Zorica M. Jakšić , Ljuba Budinski-Petković , Slobodan B. Vrhovac

The properties of the reversible Random Sequential Adsorption (RSA) of objects of various shapes on a simple three-dimensional (3D) cubic lattice are studied numerically using Monte Carlo simulations. Depositing objects are “lattice animals” made of a certain number of nearest-neighbor sites on a lattice. This work aims to investigate the impact of the geometrical properties of shapes on the temporal evolution of the density θ(t). We analyzed all lattice animals of size

n = 1, 2, 3,

and 4. The approach of the density θ(t) to the equilibrium density θ_∞ is found to be stretched exponential,

θ_{\infty} - θ (t) \sim \exp (- {(t / τ)}^{β})

, for all lattice animals. The characteristic time scale τ was found to decrease with the probability of desorption

P_{des}

according to the power law,

τ = A {(P_{des})}^{- γ}

. The exponent γ remains unchanged in all shapes of the same size. The parameter A changes depending on the number of different orientations m that the lattice animals can take when placed on a cubic lattice. Orientations of the lattice animal deposited in two randomly chosen places on the lattice are different if one of them cannot be translated into the other. Our findings indicate that the deposition dynamics slows significantly as m decreases. Furthermore, for objects of the same size, the value of parameter β increases with the number of possible orientations m of the shape. The structural heterogeneity in the local relaxation dynamics gives rise to a stretched exponential behavior of the density θ(t) with a lower value of β.

采用蒙特卡罗模拟方法研究了不同形状物体在简单三维（3D）立方晶格上的可逆随机顺序吸附特性。沉积对象是由晶格上一定数量的近邻点组成的“晶格动物”。本工作旨在研究形状的几何性质对密度θ(t)的时间演化的影响。我们分析了所有大小为n=1、2、3和4的格子动物。对于所有晶格动物，密度θ(t)到平衡密度θ∞的方法被发现是指数拉伸的，θ∞−θ(t) ~ exp（−(t/τ)β）。根据幂律，特征时间尺度τ=A(Pdes)−γ随Pdes解吸概率的减小而减小。在相同大小的所有形状中，指数γ保持不变。参数A的变化取决于放置在立方晶格上的晶格动物可以采取的不同方向m的数量。在晶格上随机选择的两个位置上沉积的晶格动物的方向是不同的，如果其中一个不能转化为另一个。我们的研究结果表明，随着m的减小，沉积动力学显著减慢。此外，对于相同尺寸的物体，参数β的值随着形状可能的方向m的数量而增加。局部弛豫动力学中的结构非均质性导致密度θ(t)呈拉伸指数行为，β值较低。

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引用次数: 0

Global stability analysis on the onset of convection in an inclined porous layer with Casson fluid under the effect of viscous dissipation and along-slope buoyancy induced throughflow 粘性耗散和顺坡浮力诱导的通流作用下卡森流体倾斜多孔层对流开始的全局稳定性分析

IF 4.6 2区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Chinese Journal of Physics

Pub Date : 2026-02-01 Epub Date: 2025-12-03 DOI: 10.1016/j.cjph.2025.12.001

Jacqueline Do Rosario e Souza , Bhagya Mathapati , Ravi Ragoju , Dhananjay Yadav

This study investigates the onset of thermal convection within a Casson fluid-saturated, inclined porous layer and accounting for the effect of viscous dissipation and along-slope buoyancy induced throughflow. The system consists of two parallel plates with an angle of inclination, ϕ from the horizontal and is analyzed using linear and nonlinear stability characteristics. Darcy law is used to describe the flow. The governing equations, including continuity, momentum, and energy balances, are first non-dimensionalized to introduce key parameters such as the Darcy–Rayleigh number, the Gebhart number, inclination angle, and the Casson fluid index. Linear stability analysis of disturbances is conducted by applying a normal mode technique. To complement the linear analysis, nonlinear stability is examined using the energy method, where an energy functional is constructed to determine thresholds for global nonlinear stability. The boundary eigenvalue problem in the two analyses are solved using the boundary value problem solver bvp4c routine in MATLAB. Comparisons between linear and nonlinear analyses are presented, supported by graphical representations of stability boundaries. The results reveal that longitudinal rolls are the most unstable modes and that inclination has a stabilizing effect, while the non-Newtonian nature of the Casson fluid tends to reduce the stability threshold. Increasing Gebhart number (stronger viscous dissipation) promotes instability, and along-slope buoyancy induced throughflow directionally shifts neutral curves-either amplifying or offsetting dissipation-induced destabilization depending on its direction. These findings provide insights into the complex interplay between fluid rheology, thermal dissipation, and system geometry, contributing to the understanding of thermal convection in porous media filled with non-Newtonian fluids.

本文研究了卡森流体饱和的倾斜多孔层内热对流的开始，并考虑了粘性耗散和沿坡浮力诱导的通流的影响。该系统由两个具有倾角的平行板组成，其中φ来自水平，并使用线性和非线性稳定性特性进行分析。达西定律用于描述流动。首先对控制方程（包括连续性、动量和能量平衡）进行无量纲化，以引入关键参数，如Darcy-Rayleigh数、Gebhart数、倾角和Casson流体指数。采用正态模态技术对扰动进行线性稳定性分析。为了补充线性分析，使用能量方法检查非线性稳定性，其中构造能量泛函以确定全局非线性稳定性的阈值。利用MATLAB中的边值问题求解器bvp4c例程对两种分析中的边值问题进行求解。给出了线性分析和非线性分析的比较，并用稳定性边界的图形表示加以支持。结果表明，纵向滚动是最不稳定的模式，而倾角具有稳定作用，而卡森流体的非牛顿性质倾向于降低稳定阈值。增加格哈特数（更强的粘性耗散）促进了不稳定性，沿坡浮力诱导的通流定向移动中性曲线——根据其方向放大或抵消耗散诱导的不稳定性。这些发现为流体流变学、热耗散和系统几何之间复杂的相互作用提供了见解，有助于理解充满非牛顿流体的多孔介质中的热对流。

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引用次数: 0

Polarization -multiplexing response based on Quasi-BIC in Quasi-flatband 基于准平坦带准bic的偏振复用响应

IF 4.6 2区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Chinese Journal of Physics

Pub Date : 2026-02-01 Epub Date: 2025-12-15 DOI: 10.1016/j.cjph.2025.12.018

Ren Guo , Miaofang Zhou , Guangtao Cao , Fan He , Jingfeng Tian , Shuyu Qiao , Hui Yang , Hairong He , Zhiying Zhu , Shaobo Liu , Tao Yu , Min Pan , Hongchao Yi , Gengbiao Lu , Yan Deng , Enduo Gao

Plasmon-induced transparency (PIT) faces limitations in integrated photonics due to low Q factors (<50) and restricted polarization control. This work integrates quasi-bound states in the continuum (QBIC) with guided-mode resonance (GMR), effectively utilizing the material advantages of silicon and silver to achieve the like-plasmon-induced absorption (like-PIA) phenomenon. This approach significantly reduces the losses associated with traditional plasmon-induced absorption (PIA) and overcomes the limitations related to performance and polarization sensitivity. Through symmetry breaking, the structure realizes dual-peak perfect absorption (98.1%/98.2%) and ultra-high Q factors (1076/816) in the near-infrared band, enhancing performance two orders over traditional devices. Band structure analysis reveals a quasi-flat band effect, rendering QBIC-controlled peaks insensitive to multi-parameter dispersion. Crucially, the dual peaks exhibit multiplexing polarization: the polarization-insensitive QBIC peak enables stable self-calibrating sensing, while the GMR-driven peak supports dynamic polarization encoding and band switching, enabling multi-parameter sensing and communication multiplexing. Additionally, the system achieves a 15.1 ps group delay, surpassing existing slow light devices. This breakthrough paves the way for polarization-multiplexed communication, environmental sensing, and multifunctional on-chip photonics.

由于低Q因子（<50）和偏振控制受限，等离子体诱导透明（PIT）在集成光子学中面临限制。本研究将连续介质中的准束缚态（QBIC）与导模共振（GMR）相结合，有效利用硅和银的材料优势，实现了类等离子体诱导吸收（like-PIA）现象。该方法显著降低了传统等离子体诱导吸收（PIA）的损耗，克服了性能和极化灵敏度方面的限制。该结构通过破对称实现了双峰完美吸收（98.1%/98.2%）和近红外波段超高Q因子（1076/816），性能比传统器件提高了两个数量级。波段结构分析揭示了准平坦带效应，使得qbic控制的峰对多参数色散不敏感。关键是，双峰表现出多路复用极化：偏振不敏感的QBIC峰支持稳定的自校准传感，而gmr驱动的峰支持动态极化编码和频带切换，实现多参数传感和通信复用。此外，该系统实现了15.1 ps的组延迟，超过了现有的慢光器件。这一突破为偏振多路通信、环境传感和多功能片上光子学铺平了道路。

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引用次数: 0

Mean energy, entropy, and specific heat of monolayer black phosphorus in the presence of a magnetic field: Non-extensive formalism 磁场作用下单层黑磷的平均能量、熵和比热：非泛化形式

IF 4.6 2区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Chinese Journal of Physics

Pub Date : 2026-02-01 Epub Date: 2025-11-22 DOI: 10.1016/j.cjph.2025.11.027

Chunyang Li , Zhanjun Li , Liu Long

A monolayer of black phosphorus (BP) is examined in the presence of an external magnetic field. The electronic energy spectrum is obtained through a tight-binding Hamiltonian, after which the non-extensive Tsallis statistical formalism is employed to evaluate the thermodynamic behavior of the system. Within this framework, the entropy, mean energy, and specific heat of the monolayer BP are systematically calculated. The results indicate that the specific heat exhibits a pronounced peak, characteristic of a Schottky-type anomaly at low temperatures. The position of this peak is temperature-dependent, while its amplitude varies with both the applied magnetic field and the non-extensive parameter q. Moreover, both the entropy and the mean energy increase monotonically with rising temperature, whereas an increase in magnetic field strength reduces the entropy at a fixed temperature.

在外加磁场的作用下，对单层黑磷（BP）进行了检测。通过紧结合哈密顿量得到电子能谱，然后采用非扩展的Tsallis统计形式评价系统的热力学行为。在此框架下，系统地计算了单层BP的熵、平均能和比热。结果表明，在低温下，比热有明显的峰值，具有肖特基型异常的特征。该峰值的位置与温度有关，其振幅随外加磁场和非扩展参数q的变化而变化。此外，熵和平均能量都随温度的升高而单调增加，而在固定温度下，磁场强度的增加使熵减小。

引用次数: 0

Oscillatory electro-magneto-hydrodynamics of third-grade fluid microflows 三级流体微流的振荡电磁流体力学

IF 4.6 2区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Chinese Journal of Physics

Pub Date : 2026-02-01 Epub Date: 2025-11-27 DOI: 10.1016/j.cjph.2025.11.028

Ruikang Yang , Zhiyong Xie , Yongjun Jian

Oscillatory electrokinetic microflows of third-grade fluids exhibit complex multi-physics coupling that challenges conventional microfluidic control. This work establishes a dynamic electro-magneto-hydrodynamic (EMHD) model based on the Debye-Hückel linearization and regular perturbation method. To address the high-order nonlinearity and transient characteristics of the momentum equation for third-grade fluids, the regular perturbation and Laplace transform approach are employed for the first time to solve the equation, deriving a semi-analytical solution that decouples transient startup and quasi-periodic flow regimes through term decomposition. Analysis reveals that memory effects—governed by the non-Newtonian dimensionless parameter a₁, which characterizes the fluid’s shear energy storage capacity—enhance oscillatory diffusion depth while suppressing velocity amplitudes as a₁ increases. Notably, domain-wide shear stress vanishes under the extreme condition a₁→∞. Synergistic analysis shows that electromagnetic field tuning optimizes flow rate via the force balance condition Ha ≈ 1.6/

η

(obtained from isocontour maximization) and achieves the peak pumping efficiency while maintaining enhanced mixing efficiency through near-wall oscillations. This framework culminates in an optimized parameter set, providing a theoretical guideline for designing microfluidic devices that balance high pumping efficiency with enhanced mixing efficiency.

三级流体的振荡电动力学微流表现出复杂的多物理场耦合，这对传统的微流控提出了挑战。本文建立了基于debye - h ckel线性化和正则摄动方法的动态电磁-磁流体动力学模型。针对三级流体动量方程的高阶非线性和瞬态特性，首次采用正则摄动和拉普拉斯变换方法求解该方程，通过项分解得到了瞬态启动和准周期流态解耦的半解析解。分析表明，记忆效应——由表征流体剪切蓄能能力的非牛顿无量纲参数a1控制——增加了振荡扩散深度，同时随着a1的增加抑制了速度振幅。值得注意的是，在极端条件a1→∞下，全域剪应力消失。协同分析表明，电磁场调谐通过力平衡条件Ha≈1.6/η（由等轮廓最大化得到）来优化流量，并通过近壁振荡达到泵送效率峰值，同时保持了提高的混合效率。该框架最终得到了一个优化的参数集，为设计平衡高泵送效率和增强混合效率的微流体装置提供了理论指导。

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引用次数: 0

Synergistic experimental–dft investigation into photocatalytic efficiency of M-Type XFe12O19 (X = Ba, Sr) hexaferrites m型XFe12O19 （X = Ba, Sr）六铁体光催化效率的协同实验- dft研究

IF 4.6 2区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Chinese Journal of Physics

Pub Date : 2026-02-01 Epub Date: 2025-11-21 DOI: 10.1016/j.cjph.2025.11.024

Shahzadi Noreen , Ayesha Awais , A.F. Abd El-Rehim , Amna Parveen , Heba Y Zahran , I.S. Yahia , Zeesham Abbas

The XFe₁₂O₁₉ (X = Ba, Sr) M-type hexaferrites were successfully synthesized using the sol-gel auto-combustion process to examine their structural, morphological, electronic, photocatalytic, and optical properties, supported by density functional theory (DFT) calculations. This work combines comprehensive experiments with first-principles calculations to clearly and comparatively explain how substituting Sr²⁺ and Ba²⁺ into the M-type XFe₁₂O₁₉ (X = Ba, Sr) structure influences the lattice, alters the electronic and optical characteristics, and impacts the material's photocatalytic behavior. The XRD analysis confirms single-phase hexagonal magnetoplumbite structures (P63/mmc) without secondary phases, with experimentally measured crystalline sizes of 44.54 nm for BaFe₁₂O₁₉ and 33.72 nm for SrFe₁₂O₁₉. The structural properties of both hexaferrites show good agreement between theoretical and experimental results. SEM images reveal plate-like morphologies with agglomerated grains, while EDX analysis confirms a stoichiometric composition. The simulated electronic band structures show direct transitions in these compositions, and calculated values match experimental results. Optical studies identify direct energy band gaps of 2.676 eV for BaFe₁₂O₁₉ and 1.602 eV for SrFe₁₂O₁₉, as determined by UV-Vis spectroscopy. BaFe₁₂O₁₉ and SrFe₁₂O₁₉ hexaferrites degraded Methylene Blue by 81% and 97%, respectively, demonstrating that the first-order kinetic model fits well with the excellent photocatalytic oxidation. Theoretical findings align with experimental results from FTIR, UV–Vis, PL, and photocatalytic tests, confirming that these compositions are promising for photocatalytic applications.

采用溶胶-凝胶自燃烧法制备了XFe12O19 (X = Ba, Sr) m型六铁体，并通过密度泛函理论（DFT）计算分析了其结构、形态、电子、光催化和光学性能。本工作将综合实验与第一性原理计算相结合，清晰、比较地解释了Sr 2 +和Ba 2 +取代m型XFe12O19 （X = Ba, Sr）结构对晶格的影响、电子和光学特性的改变以及对材料光催化行为的影响。XRD分析证实了无二次相的单相六方磁铅石结构（P63/mmc），实验测得bfe12o19和SrFe12O19的晶粒尺寸分别为44.54 nm和33.72 nm。这两种六铁氧体的结构性能与理论和实验结果吻合较好。扫描电镜图像显示板状形态，颗粒聚集，而EDX分析证实了化学计量成分。模拟的电子能带结构显示了这些成分的直接跃迁，计算值与实验结果吻合。光学研究发现，通过紫外可见光谱测定，bfe12o19的直接能带隙为2.676 eV， SrFe12O19的直接能带隙为1.602 eV。BaFe12O19和SrFe12O19六铁体对亚甲基蓝的降解率分别为81%和97%，表明一级动力学模型与优异的光催化氧化效果吻合。理论研究结果与FTIR、UV-Vis、PL和光催化测试的实验结果一致，证实了这些组合物在光催化应用方面的前景。

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引用次数: 0