在意想不到的系统中,Pt(8) Ti阶段的预测
Richard H Taylor1, Stefano Curtarolo, Gus L W Hart
1Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, USA.
Journal of the American Chemical Society
|April 28, 2010
概括
高通量搜索预测了二元过渡金属间A(8) B阶段的59次发生,显著扩大了已知的实例. 这种计算方法验证了实验发现,并揭示了材料科学中的新可能性.
科学领域:
- 材料科学 材料科学 材料科学
- 计算材料科学科学 计算材料科学
- 固态化学 固态化学
背景情况:
- 以Pt(8) Ti为例的A(8) B晶体结构是一个已知的金属间相.
- 对A(8) B阶段的实验观测仅限于11个二进制系统.
- 了解金属间相位形成对于开发具有所需性质的新材料至关重要.
研究的目的:
- 在所有二进制过渡金属间进行A(8) B阶段的全面高通量搜索.
- 为了识别A(8) B阶段的新出现,包括稳定和转移稳定的形式.
- 验证现有的实验数据,并为A(8) B阶段形成提供新的预测.
主要方法:
- 对二进制过渡金属间化合物的高通量计算选.
- 使用基于集群扩张的蒙特卡洛模型进行热力学分析.
- 与现有的实验观测对预测阶段的验证.
主要成果:
- 预计共有59个二进制系统表现出A(8) B阶段,比以前已知的11个系统大幅增加.
- 该研究发现了许多新的事件,包括在经过充分研究的系统中,如铜 (Cu-Zn).
- 在- (Rh-W) 系统中,预测了高的顺序-混乱过渡温度,证明了该方法的实际应用.
结论:
- 高通量计算方法是发现和预测金属间相的强大工具.
- 在二元过渡金属间,A(8) B阶段比以前想象的更为普遍.
- 这项研究扩大了A(8) B阶段的已知景观,并突出了计算选在材料发现中的实用性.
相关概念视频
Phase Transitions
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to occupy...
Phase Transitions
A phase transition is the process in which a substance changes from one state of matter to another, like from a solid to a liquid, liquid to gas, or vice versa, at a specific temperature and under given pressure conditions. This change is spontaneous and is affected by alterations in temperature and pressure. These parameters impact the strength of the forces between molecules (intermolecular forces) in the substance.During a phase transition, both the initial and final phases of the substance...
The Phase Rule
The phase rule describes the relationship between the variance (degrees of freedom), the number of components, and the number of phases in a system at equilibrium.Variance is a concept that denotes the number of independent intensive properties (properties are those that do not depend on the amount of material in the system), such as temperature, pressure, and composition, that can be altered without impacting the number of phases in equilibrium.In a single-component system, such as pure water,...
Phase Changes
Phase transitions play an important theoretical and practical role in the study of heat flow. In melting or fusion, a solid turns into a liquid; the opposite process is freezing. In evaporation, a liquid turns into a gas; the opposite process is condensation.
A substance melts or freezes at a temperature called its melting point and boils or condenses at its boiling point. These temperatures depend on pressure. High pressure favors the denser form of the substance, so typically, high pressure...
A substance melts or freezes at a temperature called its melting point and boils or condenses at its boiling point. These temperatures depend on pressure. High pressure favors the denser form of the substance, so typically, high pressure...
Phase Diagrams of Ternary Systems
Consider a ternary system, which is composed of three components: water (W), ethanoic acid (E), and trichloromethane (T). Here, Ethanoic acid (E) is fully miscible with both water (W) and trichloromethane (T), meaning it can mix entirely with either of them. However, water and trichloromethane have partial miscibility, meaning they can only mix to a certain extent, beyond which two separate phases will form.The phase diagram of a ternary system is represented as an equilateral triangle, where...
Phase Diagram
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
