当前位置: X-MOL 学术High Press. Res. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Experimental and theoretical P-V-T equation of state for Os2B3
High Pressure Research ( IF 2 ) Pub Date : 2020-12-26 , DOI: 10.1080/08957959.2020.1858821
Kaleb C. Burrage 1 , Chia-Min Lin 1 , Wei-Chih Chen 1 , Cheng-Chien Chen 1 , Yogesh K. Vohra 1
Affiliation  

ABSTRACT

Thermoelastic behavior of transition metal boride Os2B3 was studied under quasi-hydrostatic and isothermal conditions in a Paris-Edinburgh cell to 5.4 GPa and 1273 K. In-situ Energy Dispersive X-ray diffraction was used to determine interplanar spacings of the hexagonal crystal structure and the P-V-T data were fitted to a 3rd Order Birch–Murnaghan equation of state with a temperature modification to determine thermal elastic constants. The bulk modulus was shown to be K0 = 402 ± 21 GPa when the first pressure derivative was held to K0 = 4.0 from the room temperature P-V curve. Under a quadratic fit α=α0+α1Tα2T2, the thermal expansion coefficients were determined to be α0=1.862×105 K−1, α1=0.841×109 K−2, and α2=0.525 K. Density functional theory (DFT) with the quasi-harmonic approximation (QHA) were employed to study Os2B3, including its P-V-T curves, phonon spectra, bulk modulus, specific heat, thermal expansion, and the Grüneisen parameter. A good agreement between the first-principle theory and experimental observations was achieved, highlighting the success of the Armiento-Mattsson 2005 generalized gradient approximation functional employed in this study and QHA for describing thermodynamic properties of Os2B3.



中文翻译:

Os2B3的实验和理论PVT状态方程

抽象的

研究了过渡金属硼化物Os 2 B 3在准静态和等温条件下在Paris-Edinburgh电池中达到5.4 GPa和1273 K的弹性行为。使用原位能量色散X射线衍射确定六边形的平面间距将晶体结构和PVT数据拟合到具有温度变化的三阶Birch-Murnaghan状态方程,以确定热弹性常数。 当 从室温PV曲线将一阶压力导数保持为K 0 ' = 4.0时,体积模量显示为K 0 = 402±21 GPa 。在二次拟合下α=α0+α1个Ť-α2个Ť-2个,将热膨胀系数确定为 α0=1.862×10-5 K -1α1个=0.841×10-9 K -2α2个=-0.525 用K.密度泛函理论(DFT)和准谐波近似(QHA)研究Os 2 B 3,包括其PVT曲线,声子谱,体积模量,比热,热膨胀和Grüneisen参数。在第一原理理论和实验观察之间达成了良好的协议,突出了本研究中使用的Armiento-Mattsson 2005广义梯度逼近函数和用于描述Os 2 B 3热力学性质的QHA的成功。

更新日期:2020-12-26
down
wechat
bug