Electronic Griffiths Phase in the Te - Doped Semiconductor FeSb$_{2}$

TL;DR

This paper reports the discovery of an Electronic Griffiths Phase in Te-doped FeSb₂, revealing disorder-induced non-Fermi liquid behavior near the metal-insulator transition, with implications for understanding correlated disordered systems.

Contribution

It provides experimental evidence of an Electronic Griffiths Phase in a doped semiconductor, highlighting its presence at the metallic boundary of the phase diagram.

Findings

Signatures of non-Fermi liquid behavior observed

Electronic Griffiths Phase found near the metal-insulator transition

Strong electronic correlations indicated by Wilson ratio

Abstract

We report on the emergence of an Electronic Griffiths Phase (EGP) in the doped semiconductor FeSb$_{2}$, predicted for disordered insulators with random localized moments in the vicinity of a metal-insulator transition (MIT). Magnetic, transport, and thermodynamic measurements of Fe(Sb$_{1-x}$Te$_{x}$)$_{2}$ single crystals show signatures of disorder-induced non-Fermi liquid behavior and a Wilson ratio expected for strong electronic correlations. The EGP states are found on the metallic boundary, between the insulating state ($x = 0$) and a long-range albeit weak magnetic order ($x \geq 0.075$).