Interplay between double-exchange, superexchange, and Lifshitz localization in doped manganites
Data(s) |
01/09/2002
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Resumo |
Considering the disorder caused in manganites by the substitution Mn→Fe or Ga, we accomplish a systematic study of doped manganites begun in previous papers. To this end, a disordered model is formulated and solved using the variational mean-field technique. The subtle interplay between double exchange, superexchange, and disorder causes similar effects on the dependence of T_(C) on the percentage of Mn substitution in the cases considered. Yet, in La_(2/3)Ca_(1/3)Mn_(1-y)Ga_(y)O_(3) our results suggest a quantum critical point (QCP) for y ≈ 0.1–0.2, associated to the localization of the electronic states of the conduction band. In the case of La_(x)Ca_(x)Mn_(1-y)Fe_(y)O_(3) (with x = 1/3,3/8) no such QCP is expected. |
Formato |
application/pdf |
Identificador |
http://eprints.ucm.es/38667/1/Fern%C3%A1ndezP%C3%A9rezLuisAntonio35LIBRE.pdf |
Idioma(s) |
en |
Publicador |
American Physical Society |
Relação |
http://eprints.ucm.es/38667/ http://doi.org/10.1103/PhysRevB.66.104430 10.1103/PhysRevB.66.104430 PB96-0875 AEN99- 0990 |
Direitos |
info:eu-repo/semantics/openAccess |
Palavras-Chave | #Física #Física-Modelos matemáticos |
Tipo |
info:eu-repo/semantics/article PeerReviewed |