Abstract:
The effectofsimultaneoussubstitutionsofMninbothAandBsitesofthepyrochloretypesemiconductingoxides:(CaCe1 2xMn2x)
(Sn1 xMnxINb)O7 δ (x¼0, 0.1,0.2,0.3and0.4)ontheelectricalconductionandrelaxationwasstudiedindetailusingimpedanceanalysisasa
function offrequencyoverawiderangeoftemperature.Impedanceandmodulusanalysisclearlyexplaintherelaxationinthesematerialsandits
dependence onMnconcentration.GrainboundarydominantelectricalcharacteristicshavebeenobservedwithprogressiveMnsubstitution.
Correlated barrierhoppingmodelwassuccessfullyappliedforexplainingtheconductionmechanisminthesecompounds.Variationofhopping
parameters withMnsubstitutioninthesematerialsindicatesstrongdependenceonthegrainandgrainboundarycontributions.Thisinsighttothe
conduction mechanismofthesystemoffersintuningtheelectricalpropertiesfordesiredapplicationssuchasNTCthermistors
