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

Journal Article · Fri Nov 01 04:00:00 EST 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.54.12324· OSTI ID:388334

Schlottmann, P ^[1]

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1. Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States)

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.}

• OSTI ID: 388334
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 17 Vol. 54; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CERIUM COMPOUNDS
ELECTRONIC STRUCTURE
EXCHANGE INTERACTIONS
IMPURITIES
KONDO EFFECT
MAGNETIC PROPERTIES
PHASE TRANSFORMATIONS
SEMICONDUCTOR MATERIALS
THERMODYNAMIC PROPERTIES
URANIUM COMPOUNDS
YTTERBIUM COMPOUNDS