Preparation and electrical conductivity of(Zr,Hf,Pr,Y,La)O high entropy fluorite oxides

摘要

A series of compositionally complex fluorite oxides(CCFOs)were prepared by ball milling the mixture of ZrO_(2),HfO_(2),Y_(2)O_(3),La_(2)O_(3),and Pr_(6)O_(11)followed by conventional solid-state sintering.Both XRD and TG-DSC results demonstrated that single-phase(Zr_(0.2)Hf_(0.2)Pr_(0.2)Y_(0.2)La_(0.2))O_(2-)δwas formed at 1400°C.Elements in bulk ceramic were uniformly distributed without evident accumulation according to SEM-EDS pictures.TEM results revealed that polycrystalline ceramic powder was assignable to cubic Fm-3m fluorite structure.The electrical conductivity(σ)was measured via EIS technology and activation energy(E_(a))of CCFOs was calculated in Arrhenius plots.In the temperature range of 300-750°C,CCFOs preserved the same conduction mechanism and(Zr_(0.1667)Hf_(0.1667)Pr_(0.1667)Y_(0.25)La_(0.25))O_(2-)δpossessed higherσand lower E_(a) than other high entropy fluorite oxides which is related to the incorporation of Pr element or the connection of cation-V_(o) complex.