Tunnel Magnetocapacitance in Single-layered Fe/MgF_2 Granular Films

摘要

Magnetocapacitance (MC) effects lead to some appealing spin-based phenomena such as frequencydependentspin transport and spin capacitance, which are crucial for spintronic devices . MC offersattractive prospects for materials research and device applications such as high-frequency devices and energystorage. In magnetic nanogranular film devices, a type of MC referred to as tunnel magnetocapacitance(TMC) is observed. The advantage of using granular films is that they are relatively easy to fabricate and theyhave good thermal stability. However, the TMC ratio is smaller than 1.0% in the low-field range (～1 kOe)even for two-dimensional (2D) granular films, in which a large TMC can be expected. Here, we present abetter enhancement of TMC ratios in single-layered Fe/MgF_2 granular films.