title: Enhanced pressure dependence of magnetic exchange in A2+[V2]O4 spinels approaching the itinerant electron limit.
abstract: We report a systematic enhancement of the pressure dependence of T(N) in A(2+)[V(2)]O(4) spinels as the V-V separation approaches the critical separation for a transition to itinerant-electron behavior. An intermediate phase between localized and itinerant-electron behavior is identified in Zn[V(2)]O(4) and Mg[V(2)]O(4) exhibiting mobile holes as large polarons. Partial electronic delocalization, cooperative ordering of V-V pairs in Zn[V(2)]O(4) below T(s) approximately T(N) and dT(N)/dP<0, signals that lattice instabilities associated with the electronic crossover are a universal phenomenon.
authors.affiliation: Departamento de Química-Física, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Blanco-Canosa
authors.forename: F
authors.initials: F
authors.lastname: Rivadulla
authors.forename: V
authors.initials: V
authors.lastname: Pardo
authors.forename: D
authors.initials: D
authors.lastname: Baldomir
authors.forename: J-S
authors.initials: JS
authors.lastname: Zhou
authors.forename: M
authors.initials: M
authors.lastname: García-Hernández
authors.forename: M A
authors.initials: MA
authors.lastname: López-Quintela
authors.forename: J
authors.initials: J
authors.lastname: Rivas
authors.forename: J B
authors.initials: JB
authors.lastname: Goodenough