Novel ferroelectric and magnetic memory effect at room temperature
Magnetic control of novel electric polarization in bismuth ferrite
Institute for Solid State Physics
Efforts to develop high-density computer memory has been supported by the development of micromachining technology, but this technology is approaching its theoretical limit of development. Novel materials that act as memory at the atomic scale are the focus of intense research. One strong candidate is bismuth ferrite (BiFeO3, Bi: Bismuth, Fe: Iron, O: Oxygen), a material that shows ferroelectricity and magnetic order at room temperature.
Researchers at the Institute for Solid State Physics at the University of Tokyo, headed by Associate Professor Masashi Tokunaga, in collaboration with researchers at the National Institute of Advanced Industrial Science and Technology, Fukuoka University, Sophia University, and Aoyama Gakuin University, discovered novel electric polarization in bismuth ferrite that can be controlled by magnetic fields through accurate experiments in pulsed high magnetic fields. The direction of this electric polarization can be switched by application of a transient magnetic field, and stays even after removal of the field. This behavior is observed at room temperature and does not require energy input to maintain the polarized state, making it a suitable candidate for non-volatile memory devices.
This material offers the prospect of developing low power consumption magnetic memory devices that are tolerant of magnetic fields and can be controlled by the application of an electric field.
Press release [PDF] (Japanese)
M. Tokunaga, M. Akaki, T. Ito, S. Miyahara, A. Miyake, H. Kuwahara, and N. Furukawa,
“Magnetic control of transverse electric polarization in BiFeO3”,
Nature Communications 6 (2015) 6878, doi: 10.1038/ncomms6878.