Electronic Griffiths Phase in the Te - Doped Semiconductor FeSb${}_2$

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 ($x\ge 0.075$).

5 pages, 4 figures