Enhanced transport properties in Ce doped cobalt ferrites nanoparticles for resistive RAM applications

Polycrystalline Cerium doped Cobalt ferrite with general formula CoFex-2CexO2 (X = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5) was synthesized by Co-precipitation method. The effect of Cerium substitution on the structural, dielectric, electrical and switching properties of spinel cobalt ferrite nanoparticles was studied. Formation of the spinel structure was confirmed by X-ray Diffraction (XRD) analysis. With increase in cerium content, secondary phase (CeO2) was also identified. The frequency dependent dielectric constant, AC electrical conductivity, dielectric loss, dielectric loss tangent and impedance was investigated in the frequency range of 20Hz-3MHz. Dielectric constant, AC conductivity and dielectric loss decreased with the addition of Cerium contents. From impedance study, the role of grains and grain boundaries with in prepared spinel ferrite nanoparticles was investigated. The values the activation energies and drift mobility are calculated from the DC electrical resistivity measurements. DC resistivity and hence, activation energy increases with increasing Cerium contents. Resistive switching properties were studied using current-voltage (I-V) measurements. All I-V curves in the current study exhibit a hysteresis looptype behavior. Hysteresis loop-type trend confirm that resistive switching effect exist in Cerium doped Cobalt ferrites nanoparticles. Our study suggest that Cerium doped Cobalt ferrites have high potential for resistance switching memory devices like Resistive Random-Access Memory (ReRAM). Resistive switching mechanism in Cerium doped cobalt ferrites nanoparticles is also explained by available theoretical model. (C) 2020 Elsevier B.V. All rights reserved.