First-Order Transition from a Kondo Insulator to a Ferromagnetic Metal in Single Crystalline FeSi1-xGex
Abstract
The phase diagram of FeSi1-xGex, obtained from magnetic, thermal, and transport measurements on single crystals, shows a discontinuous transition from Kondo insulator to ferromagnetic metal with x at a critical concentration, xc≈0.25. The gap of the insulating phase strongly decreases with x. The specific heat γ coefficient appears to track the density of states of a Kondo insulator. The phase diagram is consistent with an insulator-metal transition induced by a reduction of the hybridization with x in conjunction with disorder on the Si/Ge ligand site.
- Publication:
-
Physical Review Letters
- Pub Date:
- July 2003
- DOI:
- 10.1103/PhysRevLett.91.046401
- arXiv:
- arXiv:cond-mat/0302497
- Bibcode:
- 2003PhRvL..91d6401Y
- Keywords:
-
- 71.30.+h;
- 72.15.Rn;
- 75.50.Pp;
- Metal-insulator transitions and other electronic transitions;
- Localization effects;
- Magnetic semiconductors;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- doi:10.1103/PhysRevLett.91.046401