Possible observation of the signature of the bad metal phase and its crossover to a Fermi liquid in κ-(BEDT-TTF)2Cu(NCS)2 bulk and nanoparticles by Raman scattering

M Revelli Beaumont; P Hemme; Y Gallais; A Sacuto; K Jacob; L Valade; D de Caro; C Faulmann; M Cazayous

doi:10.1088/1361-648X/abd813

Possible observation of the signature of the bad metal phase and its crossover to a Fermi liquid in κ-(BEDT-TTF)₂Cu(NCS)₂ bulk and nanoparticles by Raman scattering

J Phys Condens Matter. 2021 Jan 19;33(12):125403. doi: 10.1088/1361-648X/abd813. Online ahead of print.

Authors

M Revelli Beaumont¹, P Hemme, Y Gallais, A Sacuto, K Jacob, L Valade, D de Caro, C Faulmann, M Cazayous

Affiliation

¹ Laboratoire Matériaux et Phénomènes Quantiques (UMR 7162 CNRS), Université de Paris, 75205 Paris Cedex 13, France. Laboratoire de Chimie de Coordination (UPR 8241), Université Paul Sabatier Toulouse, France.

PMID: 33463531
DOI: 10.1088/1361-648X/abd813

Abstract

κ-(BEDT-TTF)₂Cu(NCS)₂ has been investigated by Raman scattering in both bulk and nanoparticle compounds. Phonon modes from 20 to 1600 cm^-1 have been assigned. Focusing on the unexplored low frequency phonons, a plateau in frequencies is observed in the bulk phonons between 50 and 100 K and assigned to the signature of the bad metal phase. Nanoparticles of κ-(BEDT-TTF)₂Cu(NCS)₂ exhibit anomalies at 50 K associated to the crossover from a bad metal to a Fermi liquid whose origins are discussed.