Transport anomalies in the layered compound BaPt4Se6

• Published in: npj quantum materials Vol. 6; no. 1; pp. 1 - 7
• Main Authors: Li, Sheng, Zhang, Yichen, Wu, Hanlin, Zhai, Huifei, Liu, Wenhao, Petit, Daniel Peirano, Oh, Ji Seop, Denlinger, Jonathan, McCandless, Gregory T., Chan, Julia Y., Birgeneau, Robert J., Li, Gang, Yi, Ming, Lv, Bing
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23.09.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/119; 639/766/119; Anomalies; Condensed Matter Physics; Crossovers; Electrical resistivity; Electronic structure; Honeycomb structures; Insulators; Magnetoresistivity; MATERIALS SCIENCE; Phase transitions; Photoelectric emission; Physics; Physics and Astronomy; Quantum Physics; Selenium; Structural Materials; Surfaces and Interfaces; Temperature dependence; Thin Films
• ISSN: 2397-4648; 2397-4648
• DOI: 10.1038/s41535-021-00382-x

We report a layered ternary selenide BaPt 4 Se 6 featuring sesqui-selenide Pt 2 Se 3 layers sandwiched by Ba atoms. The Pt 2 Se 3 layers in this compound can be derived from the Dirac-semimetal PtSe 2 phase with Se vacancies that form a honeycomb structure. This structure results in a Pt (VI) and Pt (II) mixed-valence compound with both PtSe 6 octahedra and PtSe 4 square net coordination configurations. Temperature-dependent electrical transport measurements suggest two distinct anomalies: a resistivity crossover, mimic to the metal-insulator (M-I) transition at ~150 K, and a resistivity plateau at temperatures below 10 K. The resistivity crossover is not associated with any structural, magnetic, or charge order modulated phase transitions. Magnetoresistivity, Hall, and heat capacity measurements concurrently suggest an existing hidden state below 5 K in this system. Angle-resolved photoemission spectroscopy measurements reveal a metallic state and no dramatic reconstruction of the electronic structure up to 200 K.