A magnetoelectric memory device based on pseudo-magnetization

Abstract

We propose a new type of magnetoelectric memory device that stores magnetic easy-axis information or pseudo-magnetization, rather than a definite magnetization direction, in magnetoelectrically coupled heterostructures. Theoretically, we show how a piezoelectric/ferromagnetic (PE/FM) combination can lead to non-volatility in pseudo-magnetization exhibiting overall ferroelectric-like behavior. The pseudo-magnetization can be manipulated by extremely low voltages especially when the FM is a low-barrier nano-magnet. Using a circuit model benchmarked against experiments, we determine the switching energy, delay, switching probability and retention time of the envisioned 1T/1C memory device in terms of magnetic and circuit parameters and discuss its thermal stability in terms of a key parameter called back-voltage vm which is an electrical measure of the strain-induced magnetic field. Taking advantage of ferromagnetic resonance measurements, we experimentally extract values for vm in CoFeB films and circular nano-magnets deposited on Pb(Mg1/3Nb2/3)0.7Ti0.3O3 which agree well with the theoretical values. Our experimental findings indeed indicate the feasibility of the proposed novel device and confirm the assumed parameters in our modeling effort.

A metastable small organic molecule for secure memory devices

“…6–16 As part of the family of electronic devices, organic electrical memory devices have attracted enormous attention. 17–33 Recently, stimuli-responsive materials have been introduced into organic electrical memory devices realizing novel performance. For example, Song and co-workers developed photoinduced multilevel memory devices whose performance could be easily tuned and controlled from bistable switching behaviour to tristable switching behaviour through UV light.…”