论文标题
在高压下NaCl的单晶弹性模量，各向异性和NaCl的B1-B2相变：实验与AB-Initio计算
Single-crystal elastic moduli, anisotropy and the B1-B2 phase transition of NaCl at high pressures: Experiment vs. ab-initio calculations
论文作者
论文摘要
使用时间域Brillouin散射（TDBS）和理论上通过密度功能理论（DFT），对NaCl的单晶弹性模量和NaCl的B1-B2相变进行了实验研究。因此，我们在很大程度上扩展了压力范围，其中测量了固体的CIJ和弹性各向异性，包括高压B2相NaCl-B2的第一个实验数据。与NaCl-B2相比，NaCl-B1具有压力各向异性的强大而增长。将使用不同晚期DFT功能获得的理论值与我们的测量值进行了比较，但是没有人能同时同时重现我们的NACL-B1和NACL-B2的实验数据。对于主剪切模量和各向异性的所有可用DFT结果，当压缩程度显着增加时，偏差变得明显。对于具有相同B1型结构和相似键的其他立方固体（例如CAO，MGO或（MG1-X，fex）o），也可以识别类似的偏差。此外，可用的实验数据表明，NaCl和上述化合物的B1 -B2相变，由天生稳定性标准C44（p）-p> 0控制。
Single-crystal elastic moduli, Cij, and the B1-B2 phase transition of NaCl were investigated experimentally, using time-domain Brillouin scattering (TDBS), and theoretically, via density-functional-theory (DFT), to 41 GPa. Thus, we largely extended pressure range where Cij and elastic anisotropy of the solid are measured, including the first experimental data for the high-pressure B2 phase, NaCl-B2. NaCl-B1 exhibits a strong and growing with pressure anisotropy, in contrast to NaCl-B2. Theoretical values obtained using different advanced DFT functionals were compared with our measurements but no one could satisfactorily reproduce our experimental data for NaCl-B1 and NaCl-B2 simultaneously. For all available DFT results on the principal shear moduli and anisotropy, the deviation became pronounced when the degree of compression increased significantly. Similar deviations could be also recognized for other cubic solids having the same B1-type structure and similar bonding, such as CaO, MgO, or (Mg1-x,Fex)O. Furthermore, the available experimental data suggest that the B1-B2 phase transition of NaCl and the above mentioned compounds are governed by the Born stability criterion C44(P) - P > 0.
