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Title: Influence of a Kondo-hole impurity band on magnetic instabilities in Kondo insulators

Abstract

Kondo insulators like Ce{sub 3}Bi{sub 4}Pt{sub 3} and CeNiSn are compounds with small-gap semiconductor properties. The Kondo insulator is described by the nondegenerate symmetric Anderson lattice with, on average, two electrons per site within Kotliar and Ruckenstein{close_quote}s mean-field approximation in terms of four slave bosons per site. A Kondo hole is the charge neutral substitution of a rare earth or actinide atom by a nonmagnetic analog. An isolated Kondo hole gives rise to a bound state in the gap, which pins the Fermi level and has magnetic properties. A finite concentration of Kondo holes generates an impurity band in the gap of the semiconductor. The low-temperature thermodynamic and transport properties are determined by the impurity band. The interplay of the {ital f}-electron correlations with the impurity band is studied in the paramagnetic phase. On a bipartite lattice the pure Kondo insulator is unstable to long-range antiferromagnetism for {ital U}{approx_gt}{ital U}{sub {ital c}} and to ferromagnetism in sufficiently large magnetic fields. A small concentration of Kondo holes reduces the threshold for the antiferromagnetic transition, giving rise to reentrance, but does not substantially affect ferromagnetism. {copyright} {ital 1996 The American Physical Society.}

Authors:
 [1]
  1. Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States)
Publication Date:
OSTI Identifier:
388334
Resource Type:
Journal Article
Journal Name:
Physical Review, B: Condensed Matter
Additional Journal Information:
Journal Volume: 54; Journal Issue: 17; Other Information: PBD: Nov 1996
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; KONDO EFFECT; IMPURITIES; SEMICONDUCTOR MATERIALS; CERIUM COMPOUNDS; YTTERBIUM COMPOUNDS; URANIUM COMPOUNDS; ELECTRONIC STRUCTURE; THERMODYNAMIC PROPERTIES; MAGNETIC PROPERTIES; PHASE TRANSFORMATIONS; EXCHANGE INTERACTIONS

Citation Formats

Schlottmann, P. Influence of a Kondo-hole impurity band on magnetic instabilities in Kondo insulators. United States: N. p., 1996. Web. doi:10.1103/PhysRevB.54.12324.
Schlottmann, P. Influence of a Kondo-hole impurity band on magnetic instabilities in Kondo insulators. United States. doi:10.1103/PhysRevB.54.12324.
Schlottmann, P. Fri . "Influence of a Kondo-hole impurity band on magnetic instabilities in Kondo insulators". United States. doi:10.1103/PhysRevB.54.12324.
@article{osti_388334,
title = {Influence of a Kondo-hole impurity band on magnetic instabilities in Kondo insulators},
author = {Schlottmann, P},
abstractNote = {Kondo insulators like Ce{sub 3}Bi{sub 4}Pt{sub 3} and CeNiSn are compounds with small-gap semiconductor properties. The Kondo insulator is described by the nondegenerate symmetric Anderson lattice with, on average, two electrons per site within Kotliar and Ruckenstein{close_quote}s mean-field approximation in terms of four slave bosons per site. A Kondo hole is the charge neutral substitution of a rare earth or actinide atom by a nonmagnetic analog. An isolated Kondo hole gives rise to a bound state in the gap, which pins the Fermi level and has magnetic properties. A finite concentration of Kondo holes generates an impurity band in the gap of the semiconductor. The low-temperature thermodynamic and transport properties are determined by the impurity band. The interplay of the {ital f}-electron correlations with the impurity band is studied in the paramagnetic phase. On a bipartite lattice the pure Kondo insulator is unstable to long-range antiferromagnetism for {ital U}{approx_gt}{ital U}{sub {ital c}} and to ferromagnetism in sufficiently large magnetic fields. A small concentration of Kondo holes reduces the threshold for the antiferromagnetic transition, giving rise to reentrance, but does not substantially affect ferromagnetism. {copyright} {ital 1996 The American Physical Society.}},
doi = {10.1103/PhysRevB.54.12324},
journal = {Physical Review, B: Condensed Matter},
number = 17,
volume = 54,
place = {United States},
year = {1996},
month = {11}
}