Functional Monochalcogenides: Raman Evidence Linking Properties, Structure, and Metavalent Bonding

Christophe Bellin (1) , Amit Pawbake (2, 1) , Lorenzo Paulatto (1) , Keevin Béneut (1) , Johan Biscaras (1) , Chandrabhas Narayana (3) , Alain Polian (1) , Dattatray J. Late (4) , Abhay Shukla (1)

1 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie
2 NEEL - MagSup - Magnétisme et Supraconductivité
3 JNCASR - Jawaharlal Nehru Centre for Advanced Scientific Research
4 Amity University

Pressure- and temperature-dependent Raman scattering in GeSe, SnSe, and GeTe for pressures beyond 50 GPa and for temperatures ranging from 78 to 800 K allow us to identify structural and electronic phase transitions, similarities between GeSe and SnSe, and differences with GeTe. Calculations help to deduce the propensity of GeTe for defect formation and the doping that results from it, which gives rise to strong Raman damping beyond anomalous anharmonicity. These properties are related to the underlying chemical bonding and consistent with a recent classification of bonding in several chalcogenide materials that puts GeTe in a separate class of “incipient” metals.

Mots clés: Anharmonic lattice dynamics; Phase diagrams; Thermoelectric systems; Density functional theory; Inelastic light scattering; Pressure techniques

Domaines: Matière Condensée [cond-mat]; Science des matériaux [cond-mat.mtrl-sci]

Christophe Bellin, Amit Pawbake, Lorenzo Paulatto, Keevin Béneut, Johan Biscaras, et al.. Functional Monochalcogenides: Raman Evidence Linking Properties, Structure, and Metavalent Bonding. Physical Review Letters, 2020, 125 (14), pp.145301. ⟨10.1103/PhysRevLett.125.145301⟩. ⟨hal-02969547⟩