负热膨胀化合物钨酸锆（ZrW2O8）的单晶弹性常数

Monocrystal elastic constants of the negative-thermal-expansion compound zirconium tungstate (ZrW2O8).

作者信息

Drymiotis F R, Ledbetter H, Betts J B, Kimura T, Lashley J C, Migliori A, Ramirez A P, Kowach G R, Van Duijn J

机构信息

Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.

出版信息

Phys Rev Lett. 2004 Jul 9;93(2):025502. doi: 10.1103/PhysRevLett.93.025502. Epub 2004 Jul 8.

DOI:10.1103/PhysRevLett.93.025502

PMID:15323925

Abstract

We measured zirconium tungstate's elastic constants C(ij). This compound shows relatively soft, nearly isotropic elastic constants with normal Poisson ratios and no approach to Born instability. ZrW2O8 shows normal ambient-temperature elastic constants C(ij), but remarkable dC(ij)/dT that show dominant low-frequency acoustic-vibration modes. From the bulk modulus, we estimated the total ambient-temperature thermodynamic Grüneisen parameter as gamma = -1.2. The dB/dT slope gives a Grüneisen parameter gamma = -7. The 300-0 K bulk-modulus increase (40%) seems unprecedented and breaks Birch's law of corresponding states.

摘要

我们测量了钨酸锆的弹性常数C(ij)。该化合物表现出相对较软、近乎各向同性的弹性常数，泊松比正常，且未趋近于玻恩不稳定性。ZrW2O8在常温下具有正常的弹性常数C(ij)，但dC(ij)/dT显著，显示出主导的低频声振动模式。根据体积模量，我们估计常温下的总热力学格林爱森参数为γ = -1.2。dB/dT斜率给出的格林爱森参数γ = -7。300 - 0 K时体积模量增加40%似乎是前所未有的，并且打破了伯奇对应态定律。