Voltage Control of Magnetism above Room Temperature in Epitaxial SCFO

PI: Caroline Ross and Riccardo Comin

Intellectual Merit
Searching for new materials and phenomena to enable voltage control of magnetism and magnetic properties holds compelling interest for the development of low-power non-volatile memory devices. Here, we report on a non-volatile ON/OFF voltage control of magnetism in thin films of an oxide, SrCo1-xFexO3-δ (SCFO). For Co/Fe ratio of ~1:1, a switch between nonmagnetic (OFF) and ferromagnetic (ON) state at and above room temperature is accomplished by ionic liquid gating at ambient conditions with voltages as low as ±2 V.

Magnetism is switched ON by negative voltage (middle) and OFF by positive voltage. This can be repeated multiple times (below).

Broader Impacts
Device Applications: The magnetization switching can allow voltage-driven memory or logic devices. The accompanying notable structural changes can allow strain coupling to another material. This provides new platforms for voltage-controlled and strain-mediated novel functionalities based on couplings between structure, composition and physical properties.

Top: A composite made of the ON/OFF magnetic material
surrounding crystals of another magnetic oxide.

Public Outreach: NanoObservatory event is held during the Cambridge Science Festival. On-line education is accomplished through edX, where the PI’s class on Optical, Electrical and Magnetic Materials and Devices is offered free to the public.

Bottom: The NanoObservatory in 2019