Researchers have successfully observed the world's largest tunnel magnetocapacitance (TMC) ratio and explained its mechanism. The research team was comprised of Kenta Sato, a second-year master's student at Keio University's Graduate School of Science and Technology, Hideo Kaiju, Associate Professor at Keio University's Faculty of Science and Technology, and colleagues including Hiroaki Sukegawa, Principal Researcher at the National Institute for Materials Science and Gang Xiao, Professor of Physics at Brown University, USA.
TMC is a phenomenon in which capacitance (electrical capacitance, or the amount of electricity that a system can store) changes based on a magnetic field. This phenomenon is observed in textured magnetic tunnel junctions (MTJs) with a thin insulating layer between two magnetic layers. Until now, the largest observed TMC ratio, a figure-of-merit on magnetic sensitivity, has been 332%. In this study, researchers achieved the world's largest TMC ratio of 426% by using an insulation tunneling layer and applying voltage biasing. Furthermore, they explained the mechanism behind this phenomenon using dielectric theory, which incorporates quantum mechanics and statistical theory. These results pave the way for creating new capacitance-detecting, high-performance magnetic sensors and magnetic memory devices.
The research results were published online in Scientific Reports (via Springer Nature Group) on May 16 (BST).