Magnetism and electrode dependant resistive switching in Ca-doped ceramic bismuth ferrite

Here we report on the preparation and structural, magnetic and electrical characterization of BiFeO3 and Bi0.9Ca0.1FeO3 ceramic multiferroic samples. We suggest that Ca-doping creates oxygen vacancies and destabilizes the BiFeO3 spiral magnetic structure. We also study resistive switching effects in Bi0.9Ca0.1FeO3 with metallic electrodes, finding that the appearance of the effect is dependant on the fabrication procedure of the metallic electrode. On the basis of these observations, we critically revise some assumptions in currently available models of resistive switching of complex oxides.

► We synthesized ceramic samples of BiFeO3 and Bi0.9Ca0.1FeO3.
► We show by means of Mössbauer spectroscopy that the Fe valence remains 3+ upon Ca-doping.
► We show that Ca-doping reduces the transition field from the spatially modulated to the collinear magnetic state.
► We suggest that resistive switching in Ag/Bi0.9Ca0.1FeO3 system is related to the formation of AgOx at the interface.