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Non‐magnetic Kondo effect in M –As–Se ( M = Zr, Hf, Th) phases
Author(s) -
Cichorek Tomasz,
Bochenek Lukasz,
Henkie Zygmunt,
Schmidt Marcus,
Czulucki Andreas,
Kniep Rudiger,
Steglich Frank
Publication year - 2010
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200983059
Subject(s) - electrical resistivity and conductivity , condensed matter physics , kondo effect , tetragonal crystal system , magnetic field , hall effect , magnetoresistance , electron , diffusion , materials science , chemistry , physics , crystallography , thermodynamics , crystal structure , quantum mechanics
Thermodynamic and transport properties of the tetragonal M –As–Se ( M = Zr, Hf, Th) phases demonstrate that these materials are disordered metals with the electronic‐specific‐heat coefficient as small as, e.g., 0.3 mJ K −2 mol −1 for Th–As–Se. Remarkably, all the M –As–Se systems display a magnetic‐field‐independent AT 1/2 term in the low‐temperature electrical resistivity. As observed for ZrAs 1.595 Se 0.393 , the magnitude of this extra term may vary by a factor of nearly 3 as well as the resistivity minimum is shifted from 10.8 to about 15.0 K, dispite virtually the same electron‐diffusion constant. On the other hand, a magnetic‐field ( B ≤ 14 T) dependence of the electron transport in arsenide selenides is strongly material dependent: both the positive and negative sign of the magnetoresistivity being proportional to either B 2 or B 1/2 were found. These observations point to a non‐magnetic Kondo effect due to a random distribution of structural two‐level systems in the disordered As/Se sublattice.