Cubic lead perovskite PbMoO3 with anomalous metallic behavior
Cubic lead perovskite PbMoO3 with anomalous metallic behavior
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具有异常金属行为的立方铅钙钛矿 PbMoO3
DOI：
10.1103/physrevb.95.155105
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
and Hiroshi Kageyama
中科院分区：
文献类型：
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作者：
Hiroshi Takatsu;Olivier Hernandez;Wataru Yoshimune;Carmelo Prestipino;Takafumi Yamamoto;Cedric Tassel;Yoji Kobayashi;Dmitry Batuk;Yuki Shibata;Artem M. Abakumov;Craig M. Brown;and Hiroshi Kageyama
通过高压高温合成得到了一种未见报道的铅基钙钛矿。这种材料在室温下以立方结构结晶，使其不同于典型的具有结构畸变的Pb基钙钛矿氧化物。此外，在低温下观察到一个大的比热，并在10 K附近出现一个峰值，与等结构金属系统形成鲜明对比。考虑到通过衍射实验检测到的超大Pb原子位移，这些运输和热性质归因于低能量振动模式，与非相干偏心孤对阳离子。我们讨论了不寻常的行为的电阻率的极化子传导，介导的传导电子和光学声子的本地低能振动模式之间的强耦合。
A previously unreported Pb-based perovskiteis obtained by high-pressure and high-temperature synthesis. This material crystallizes in thecubic structure at room temperature, making it distinct from typical Pb-based perovskite oxides with a structural distortion.exhibits a metallic behavior down to 0.1 K with an unusual-sublinear dependence of the electrical resistivity. Moreover, a large specific heat is observed at low temperatures accompanied by a peak inaround 10 K, in marked contrast to the isostructural metallic system. These transport and thermal properties for, taking into account anomalously large Pb atomic displacements detected through diffraction experiments, are attributed to a low-energy vibrational mode, associated with incoherent off-centering of lone-paircations. We discuss the unusual behavior of the electrical resistivity in terms of a polaronlike conduction, mediated by the strong coupling between conduction electrons and optical phonons of the local low-energy vibrational mode.