Generalized estimates for thermal expansion of oxide scale in the range from 0C to 1300C with account for movability of phase transitions in its components
The thermophysical properties of oxide scale, in the general case, are affected by the variation of the temperature of phase transitions (either magnetic or polymorphic) in its components due to impurities, lattice defects, grain sizes, etc. In this case, since the phase transition is usually accompanied by a sharp change in properties, even a small shift of such a critical temperature can lead to large changes in properties in its vicinity. In order to account for this effect, data known from various sources on the true coefficient of linear thermal expansion (CLTE) of wüstite , magnetite , hematite , and metallic iron are generalized by approximating functions that include critical temperatures as variable parameters. It is shown that the true CLTE of magnetite at the same rated temperature can differ by up to 30% depending on the position of the Curie point within the limits of its possible "movability". The proposed methods allow to take into account the critical temperatures as adaptation parameters in engineering calculations of thermal expansion of oxide scale. Generalized formulas for each scale component are also given in a particular form for fixed (basic) values of critical temperatures. The dependence of the true CLTE of oxide scale as a whole (αsc) on the volume fraction of each component is proposed. It is shown by model computations that there are temperatures at which αsc is almost independent of the scale composition, as well as areas of instability, where αsc depends significantly on the percentage of components. The results of the work are recommended to be used when mathematical modeling of production and processing of steel products in the presence of oxide scale on their surface.
Thermal conductivity of oxide scale and its components in the range from 0 C to 1300 C: Generalized estimates with account for movability of phase transitions
Development of an Atomic Cluster Expansion potential for iron and its oxides
Max Planck Institute for Sustainable Materials（马克斯·普朗克可持续材料研究所）；Interdisciplinary Centre for Advanced Materials Simulations, Ruhr Universität Bochum（波鸿鲁尔大学跨学科高级材料模拟中心）
Evaluation of Neel temperatures from fully self-consistent broken-symmetry GW and high-temperature expansion: application to cubic transition-metal oxides
A Corkscrew Model for Highly Coupled Anisotropic Compliance in Ruddlesden-Popper Oxides with Frozen Octahedral Rotations
一个“螺旋”的机制，耦合的变化，在平面内的旋转角度的应变沿分层轴，已被提出来解释增加的顺应性在某些Ruddlesden-Popper阶段，促进单轴负热膨胀在一个很宽的温度范围内。开发的程序来研究许多简单的，拉胀几何形状，在本研究中，我们推导出的弹性顺应性预测的螺旋机制假设四个最短的金属-阴离子键保持刚性和键角的变化建模的谐波角电位。随后，我们分析了这个模型的局限性，并表明，它可以扩展到An+1BnO 3 n +1 Ruddlesden-Popper氧化物相的一般层厚度n。
A Topotactic Phase Transition in the Uranium Oxide System
University of Bristol（布里斯托大学）；ICSM, Univ Montpellier, CEA, CNRS, ENSCM（蒙彼利埃大学 ICSM 研究所）；Department of Materials, University of Oxford（牛津大学材料系）；Department of Materials Design and Manufacturing, School of Engineering, University of Liverpool（利物浦大学工程学院材料设计与制造系）
Automated Phase Mapping with AgileFD and its Application to Light Absorber Discovery in the V-Mn-Nb Oxide System
快速构建相图是组合材料科学的核心原则，加速材料发现的努力往往受到解释组合X射线衍射数据集的挑战的阻碍，我们通过开发AgileFD来解决这个问题，AgileFD是一种人工智能算法，可以从X射线衍射图案的组合库中快速绘制相位图。AgileFD通过卷积非负矩阵分解的新扩展对基于合金的峰位移进行建模，这不仅改善了组成相的识别，而且还将其浓度和晶格参数映射为组成的函数。通过将Gibbs相位规则引入算法，在无监督操作的情况下得到有物理意义的相位图，并通过注入系统的专家知识得到更精细的解。该算法是证明通过调查的V-Mn-Nb氧化物系统，其中分解的8个氧化物相，包括两个大量的合金化，提供了第一个相图为这个伪三元系统。该相图能够解释高通量带隙数据，从而发现新的太阳光吸收剂和基于合金的MnV 2 O 6直接允许带隙能量的调谐。AgileFD算法的开源系列可以在广泛的高通量工作流程中实施，以加速材料发现。
Biaxial Strain Control of Helimagnetism via Chemical Expansion in Thin Film SrFeO3
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory（斯坦福材料能源科学研究所，SLAC国家加速器实验室）；Department of Applied Physics, Stanford University（斯坦福大学应用物理系）；Department of Materials Science and Engineering, Northwestern University（西北大学材料科学与工程系）；Singh Center for Nanotechnology, University of Pennsylvania（宾夕法尼亚大学辛格纳米技术中心）；Center for Natural Sciences and Humanities, Federal University of ABC - UFABC（联邦ABC大学自然科学与人文中心）；Department of Physics, University of Johannesburg（约翰内斯堡大学物理系）；Canadian Light Source（加拿大光源）；ISIS Neutron and Muon Source, STFC Rutherford Appleton Laboratory（STFC拉瑟福德阿普尔顿实验室ISIS中子与μ子源）
Cation Disorder and Lithium Insertion Mechanism of Wadsley--Roth Crystallographic Shear Phases
Wadsley-Roth晶体剪切相形成了一个化合物家族，由于其作为锂离子电池电极的优异性能而引起了人们的关注。这些材料复杂的晶体结构对第一原理计算建模提出了挑战，并阻碍了对其结构，电子和动态特性的理解。在本文中，我们研究了三种不同的铌-钨氧化物晶体剪切相，（Nb $_{12}$ WO $_{33}$，Nb $_{14}$ W $_{3}$ O $_{44}$，Nb $_{16}$ W $_5$ O $_{55}$）使用基于枚举的方法，原理密度泛函理论计算。我们报告的共同原则，这些材料的阳离子无序，锂插入机制，和电子结构。钨优先占据块型晶体结构内的四面体和块中心位置。锂的插入通过三步机制进行，与主晶格的各向异性演化相关联。我们的计算揭示了长程和局部结构变化之间的重要联系：在该机制的第二步中，局部结构扭曲的消除导致晶格沿特定晶体学方向收缩，缓冲材料的体积膨胀。铌-钨氧化物剪切结构在初始锂插入期间由于块的限制效应而托管少量的局部电子，但在进一步锂化时迅速变成金属。我们认为，在锂化过程中，局部，长程和电子结构演变的结合有利于这些材料作为电池电极的性能。我们建立的机械原理产生于化合物独立的晶体学剪切结构，因此可能适用于Ti/Nb氧化物或纯Nb氧化物剪切相。
Direct coupling of first-principles calculations with replica exchange Monte Carlo sampling of ion disorder in solids
我们证明了直接从第一原理进行足够的无序氧化物的构型采样的可行性，而不诉诸于使用拟合模型，如集群扩展。这是通过利用现代集群超级计算机的能力，使用副本交换蒙特卡罗方法直接与密度泛函代码执行的结构弛豫和能量计算相结合来实现的。这一思想被成功地应用于计算MgAl $_2$ O $_4$尖晶石氧化物的阳离子亚晶格的反转度随温度的变化关系。绕过拟合模型的可能性将导致对无序系统的研究，其中已知簇膨胀表现不佳：例如，由于缺陷而具有大晶格变形的系统，或长程相互作用占主导地位的系统，如电化学界面。
Real-time Observation of Thermal Surface Recovery in $SrVO_3$
Andrew and Erna Viterbi Department of Electrical and Computer Engineering, Technion—Israel Institute of Technology（以色列理工学院安德鲁和埃尔娜·维特比电气与计算机工程系）；Air Force Research Laboratory（空军研究实验室）；UES BlueHalo Company（UES BlueHalo公司）
Low-temperature nanoscale heat transport in a gadolinium iron garnet heterostructure probed by ultrafast x-ray diffraction
利用时间分辨X射线衍射技术研究了Pt/Gd 3Fe 5 O 12//Gd 3Ga 5 O 12金属/氧化物异质结的低温热输运性质。脉冲飞秒光信号在Pt层中产生快速的温度上升，随后热传输到Gd 3Fe 5 O 12（GdIG）薄膜和Gd 3Ga 5 O 12（GGG）衬底中。使用基于加速器的飞秒X射线源跟踪来自GdIG层的X射线衍射的时间依赖性。超快衍射测量探测GdIG（1 - 1 2）X射线反射在掠入射X射线衍射几何结构中的强度。的衍射X射线强度的变化与模型，包括热传输和GdIG晶格参数的温度依赖性的比较允许的Pt/GdIG和GdIG//GGG接口的热导率被确定。GdIG层的低温热膨胀性质的互补同步加速器X射线衍射研究提供了GdIG晶格参数的温度依赖性的精确校准。从时间分辨衍射研究确定的Pt/GdIG和GdIG//GGG接口的界面热导是相同的数量级的金属/氧化物和外延介电界面的先前报告。Pt/GdIG//GGG异质结构的热参数将有助于热传输器件和纳米结构的设计和实现。
