Temperature and pressure effects on the crystal structure of Sr{sub 3}Ru{sub 2}O{sub 7}: Evidence for electronically driven structural responses
Temperature and pressure effects on the crystal structure of Sr{sub 3}Ru{sub 2}O{sub 7}: Evidence for electronically driven structural responses
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温度和压力对 Sr{sub 3}Ru{sub 2}O{sub 7} 晶体结构的影响：电子驱动结构响应的证据
DOI：
10.1103/physrevb.62.8725
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发表时间：
2000
影响因子：
3.7
通讯作者：
Y. Maeno
中科院分区：
文献类型：
--
作者：
H. Shaked;J. Jorgensen;S. Short;O. Chmaissem;S. Ikeda;Y. Maeno
用中子衍射研究了Sr 3 Ru 2 O 7的晶体结构随温度（5- 305 K）和压力（环境压力-0.62 GPa）的变化。随着温度的降低，晶格常数c和氧八面体旋转角φ在305 K>T> 50 K时增大，在20 K>T> 5 K时减小。当在室温下施加压力时，外部顶端Ru-O键膨胀。这种显着的行为进行了讨论，在修改的Ru{sup 4+}离子在氧八面体的晶体电场和交叉费米液体行为在低温下的能级的占用。在烧结粉末样品中，非常各向异性的热膨胀导致高度的应变，该应变随着每个冷却循环而稍微减轻。
The crystal structure of the ruthenate Sr{sub 3}Ru{sub 2}O{sub 7} as a function of temperature (5--305 K) and pressure (ambient -0.62 GPa) was studied by neutron diffraction. Upon cooling, the lattice parameter c and the rotation angle of the oxygen octahedra {phi} increase for 305K>T>50K, and decrease for 20K>T>5K. As pressure is applied at room temperature, the outer apical Ru-O bond expands. This remarkable behavior is discussed in terms of modification of the occupation of energy levels of the Ru{sup 4+} ion in the crystalline electric field of the oxygen octahedron and a crossover to Fermi-liquid behavior at low temperature. The very anisotropic thermal expansion leads, in sintered powder samples, to a high degree of strain, which is relieved somewhat with each cooling cycle.