scholarly journals Transport anomalies in the layered compound BaPt4Se6

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Sheng Li ◽  
Yichen Zhang ◽  
Hanlin Wu ◽  
Huifei Zhai ◽  
Wenhao Liu ◽  
...  
Keyword(s):  
Electrical Transport ◽  
Mixed Valence ◽  
Charge Order ◽  
Honeycomb Structure ◽  
Layered Compound ◽  
Metallic State ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Dirac Semimetal ◽  
Mixed Valence Compound ◽  
Heat Capacity Measurements

AbstractWe report a layered ternary selenide BaPt4Se6 featuring sesqui-selenide Pt2Se3 layers sandwiched by Ba atoms. The Pt2Se3 layers in this compound can be derived from the Dirac-semimetal PtSe2 phase with Se vacancies that form a honeycomb structure. This structure results in a Pt (VI) and Pt (II) mixed-valence compound with both PtSe6 octahedra and PtSe4 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.

scholarly journals Observation and control of the weak topological insulator state in ZrTe5

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peng Zhang ◽  
Ryo Noguchi ◽  
Kenta Kuroda ◽  
Chun Lin ◽  
Kaishu Kawaguchi ◽  
...  
Keyword(s):  
Band Gap ◽  
Topological Insulator ◽  
Spin Current ◽  
Side Surface ◽  
Quantum Spin ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Dirac Semimetal ◽  
Topological States ◽  
The One ◽  
And Control

AbstractA quantum spin Hall (QSH) insulator hosts topological states at the one-dimensional (1D) edge, along which backscattering by nonmagnetic impurities is strictly prohibited. Its 3D analogue, a weak topological insulator (WTI), possesses similar quasi-1D topological states confined at side surfaces. The enhanced confinement could provide a route for dissipationless current and better advantages for applications relative to strong topological insulators (STIs). However, the topological side surface is usually not cleavable and is thus hard to observe. Here, we visualize the topological states of the WTI candidate ZrTe5 by spin and angle-resolved photoemission spectroscopy (ARPES): a quasi-1D band with spin-momentum locking was revealed on the side surface. We further demonstrate that the bulk band gap is controlled by external strain, realizing a more stable WTI state or an ideal Dirac semimetal (DS) state. The highly directional spin-current and the tunable band gap in ZrTe5 will provide an excellent platform for applications.

Comment on “Pressure-induced structural and valence transition in AgO” by C. Hou, J. Botana, X. Zhang, X. Wang and M. Miao, Phys. Chem. Chem. Phys., 2016, 18, 15322

2016 ◽  
Vol 18 (46) ◽  
pp. 31973-31974 ◽  
Author(s):  
Mariana Derzsi ◽  
Wojciech Grochala
Keyword(s):  
Electronic Structure ◽  
Recent Article ◽  
Theoretical Study ◽  
Mixed Valence ◽  
Chem Phys ◽  
External Pressure ◽  
Valence Transition ◽  
Mixed Valence Compound ◽  
Phys Chem Chem Phys

The recent article by Hou et al. has focused on a theoretical study of mixed valence compound AgO in order to elucidate the nature of the electronic structure of this system as a function of external pressure.

Singlet carbenes as mimics for transition metals: synthesis of an air stable organic mixed valence compound [M2(C2)+˙; M = cyclic(alkyl)(amino)carbene]

2014 ◽  
Vol 1 (4) ◽  
pp. 351-354 ◽  
Author(s):  
Liqun Jin ◽  
Mohand Melaimi ◽  
Liu Liu ◽  
Guy Bertrand
Keyword(s):  
Transition Metals ◽  
Radical Cation ◽  
Mixed Valence ◽  
Ethynyl Radical ◽  
Mixed Valence Compound ◽  
Singlet Carbenes

A bis-carbene-stabilized ethynyl radical cation, a purely organic mixed valence compound, is indefinitely air stable.

Incoherent strange metal sharply bounded by a critical doping in Bi2212

Science ◽  
2019 ◽  
Vol 366 (6469) ◽  
pp. 1099-1102 ◽  
Author(s):  
Su-Di Chen ◽  
Makoto Hashimoto ◽  
Yu He ◽  
Dongjoon Song ◽  
Ke-Jun Xu ◽  
...  
Keyword(s):  
High Temperature Superconductors ◽  
Quantum Critical Point ◽  
Critical Value ◽  
Photoemission Spectroscopy ◽  
Metallic State ◽  
Zone Boundary ◽  
Brillouin Zone Boundary ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Normal Metals ◽  
Superconducting Fluctuations

In normal metals, macroscopic properties are understood using the concept of quasiparticles. In the cuprate high-temperature superconductors, the metallic state above the highest transition temperature is anomalous and is known as the “strange metal.” We studied this state using angle-resolved photoemission spectroscopy. With increasing doping across a temperature-independent critical value pc ~ 0.19, we observed that near the Brillouin zone boundary, the strange metal, characterized by an incoherent spectral function, abruptly reconstructs into a more conventional metal with quasiparticles. Above the temperature of superconducting fluctuations, we found that the pseudogap also discontinuously collapses at the very same value of pc. These observations suggest that the incoherent strange metal is a distinct state and a prerequisite for the pseudogap; such findings are incompatible with existing pseudogap quantum critical point scenarios.

Crystal structure and properties of a new mixed-valence compound LiMn2TeO6 and the survey of the LiMM′XO6 family (X = Sb or Te)

2011 ◽  
Vol 13 (11) ◽  
pp. 1931-1937 ◽  
Author(s):  
A.A. Pospelov ◽  
V.B. Nalbandyan ◽  
E.I. Serikova ◽  
B.S. Medvedev ◽  
M.A. Evstigneeva ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mixed Valence ◽  
Structure And Properties ◽  
Mixed Valence Compound

Effect of pressure on resistivity and Mössbauer spectra of the mixed valence compound Sn2S3

1979 ◽  
Vol 70 (11) ◽  
pp. 4837-4842 ◽  
Author(s):  
G. Amthauer ◽  
J. Fenner ◽  
S. Hafner ◽  
W. B. Holzapfel ◽  
R. Keller
Keyword(s):  
Mössbauer Spectra ◽  
Mixed Valence ◽  
Effect Of Pressure ◽  
Mossbauer Spectra ◽  
Mixed Valence Compound
Sign in / Sign up

Export Citation Format

Share Document