Tunneling Magnetodielectric Effect in Co-Al2O3 Granular Films

In this study, we investigated the tunneling magnetodielectric (TMD) effect in cobalt -aluminum-oxide (Co-Al2O3) nanogranular films. The films showed a homogeneous granular structure composed of nanometer Co granules dispersed in an Al2O3 matrix and demonstrated a TMD response with a maximum TMD ratio {(3/4'H=850kA/m 3/4'H=0kA/m)/3/4'H=0kA/m} of 1.1% at a frequency of 5.0 MHz at room temperature. These results show the existence of the TMD effect in the magnetic metal -oxide composite, which would promote the wide applications of the magnetic metal -oxide nanogranular materials in magnetoelectric devices. [doi:10.2320/matertrans.MT-M2022098]