Interplay between Phonons and Anisotropic Elasticity Drives Negative Thermal Expansion in PbTiO3
Interplay between Phonons and Anisotropic Elasticity Drives Negative Thermal Expansion in PbTiO3
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声子和各向异性弹性之间的相互作用驱动 PbTiO3 的负热膨胀
DOI：
10.1103/physrevlett.121.255901
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发表时间：
2018
影响因子：
8.6
通讯作者：
Benedek, Nicole A.
中科院分区：
文献类型：
--
作者：
Ritz, Ethan T.;Benedek, Nicole A.
我们使用第一性原理理论表明，成分假设是必不可少的负热膨胀（NTE）的发生-刚性单位声子模式与负Grüneisen参数-既不充分，也不必要的材料进行NTE。相反，我们发现，NTE ininininininvolves一个微妙的相互作用之间的声子性质的材料（Grüneisen参数）和它的各向异性弹性。这些独特的见解为我们对材料热性能的基本理解和在新材料类别中寻找NTE开辟了新的途径。
We use first-principles theory to show that the ingredients assumed to be essential to the occurrence of negative thermal expansion (NTE)—rigid unit phonon modes with negative Grüneisen parameters—are neither sufficient nor necessary for a material to undergo NTE. Instead, we find that NTE ininvolves a delicate interplay between the phonon properties of a material (Grüneisen parameters) and its anisotropic elasticity. These unique insights open new avenues in our fundamental understanding of the thermal properties of materials and in the search for NTE in new materials classes.