Cubic lead perovskite PbMoO3 with anomalous metallic behavior

• Published in: arXiv.org
• Main Authors: Takatsu, Hiroshi, Hernandez, Olivier, Yoshimune, Wataru, Prestipino, Carmelo, Yamamoto, Takafumi, Tassel, Cedric, Kobayashi, Yoji, Batuk, Dmitry, Shibata, Yuki, Abakumov, Artem M, Brown, Craig M, Kageyama, Hiroshi
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 05.04.2017
• Subjects: Conduction electrons; Dependence; Electrical resistivity; High temperature; Lead; Perovskites; Physics - Materials Science; Physics - Strongly Correlated Electrons; Thermodynamic properties
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1704.01270

A previously unreported Pb-based perovskite PbMoO\(_3\) is obtained by high-pressure and high-temperature synthesis. This material crystallizes in the \(Pm\bar{3}m\) cubic structure at room temperature, making it distinct from typical Pb-based perovskite oxides with a structural distortion. PbMoO\(_3\) exhibits a metallic behavior down to 0.1 K with an unusual \(T\)-sub linear dependence of the electrical resistivity. Moreover, a large specific heat is observed at low temperatures accompanied by a peak in \(C_P/T^3\) around 10 K, in marked contrast to the isostructural metallic system SrMoO\(_3\). These transport and thermal properties for PbMoO\(_3\), 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 pair Pb\(^{2+}\) cations. We discuss the unusual behavior of the electrical resistivity in terms of a polaron-like conduction, mediated by the strong coupling between conduction electrons and optical phonons of the local low-energy vibrational mode.