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Pressure-induced structural transition and metallization in MnSe2.

Authors :
Wang, Baoyun
Wang, Xiaoning
Wang, Simeng
Tan, Dayong
Xiao, Wansheng
Liang, Wen
Song, Maoshuang
Source :
Physics & Chemistry of Minerals. Sep2020, Vol. 47 Issue 9, p1-10. 10p.
Publication Year :
2020

Abstract

The high-pressure behavior of manganese diselenide MnSe2 was investigated by synchrotron angle-dispersive X-ray diffraction (ADXRD) and infrared reflection spectroscopy equipped with a diamond-anvil cell. It was found that MnSe2 with a pyrite-type structure undergoes a transformation into a disordered intermediate phase at ~ 12.5 GPa, with a ground state composed of an arsenopyrite-type structure, as confirmed by laser-heating treatment. The pyrite to arsenopyrite phase transition was found to be coupled to a large collapse in the unit-cell volume (∆V ~ 19%) and an electronic transition from a high-spin to low-spin state for manganese cations (Mn2+). With a fixed value for the pressure derivation of the bulk modulus K' = 4, fitting of the pressure–volume data to a second-order Birch–Murnaghan equation of state yielded isothermal bulk modulus values of K0 = 56.1(9) GPa and K0 = 93.1(4) GPa for the pyrite-type and arsenopyrite-type phases, respectively. The measured infrared reflectivity (Rsd) for MnSe2 showed a drastic increase at pressures between 13 and 20 GPa, but became insensitive to pressure under further compression, implying a pressure-induced transition from an insulator to metallic state. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
03421791
Volume :
47
Issue :
9
Database :
Academic Search Index
Journal :
Physics & Chemistry of Minerals
Publication Type :
Academic Journal
Accession number :
146113375
Full Text :
https://doi.org/10.1007/s00269-020-01111-9