LAUSR

Tunnel-type magneto-dielectric (TMD) effect arising from the spin-dependent quantum tunneling between nano-sized granular pairs, has opened up new route for room temperature magnetoelectric fields. We first investigated the TMD properties in metal-oxide (Co­SiO2) granular films and their annealing effect in this work. Results show that the films exhibit a TMD ratio ( 3⁄4=3⁄40) of 1% with high electrical resistivity of >108 μ3·m and intermediate optical transmittance in Co0.24­(SiO2)0.76 films. Annealing investigations suggest that the samples remain TMD response up to 573K, and further increment in annealing temperature leads to the inter-diffusion between Co and SiO2 interfaces, thus producing the increasing oxidation of metallic Co. This study demonstrates the possibility of TMD effect in metal-oxide composite materials, and may be desirable for a variety of other wide oxide-based candidates for magnetoelectric device applications. [doi:10.2320/matertrans.MBW201712]