College Park, MD (August 24, 2010) -- Chinese scientists have shown that magnetic memory, logic and sensor cells can be made faster and more energy efficient by using an electric, not magnetic, field to flip the magnetization of the sensing layer only about halfway, rather than completely to the opposite direction. They describe the new cell design in the Journal of Applied Physics, which is published by the American Institute of Physics (AIP).
Magnetic random access memory (or MRAM) cells have long been investigated as possible replacements for parts of hard disk drives, flash memory and even computing circuits. Previous designs, however, have proven to be too power-hungry or expensive to be competitive.
"Our new cell design offers a great possibility for data storage elements and logic gates that are fast and non-volatile with ultra-low power consumption," said Dr. Ce-Wen Nan of Tsinghua University in Beijing, China. The new cell is also simpler to make than existing components. Only two layers are needed, compared with three or more for traditional magnetic memories.
The design by Nan's group is a simple thin-layer sandwich of two different materials, each of which has very different magnetic and electrical properties. Applying a voltage to the ferroelectric layer switches its polarization in a way that starts to change the magnetic orientation of the adjacent ferromagnetic layer. This partial change alters the electrical resistance of the entire stack enough to indicate whether the cell is storing a "0" or a "1" data bit. Future research is aimed at understanding and optimizing the materials to increase the resistance change, which will enhance its commercial prospects.
The article, "A simple bi-layered magnetoelectric random access memory cell based on electric-field controllable domain structure" by Ce-Wen Nan will appear in the Journal of Applied Physics. http://jap.
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This work was supported by NSF of China and the National Basic Research Program of China.
ABOUT Journal of Applied Physics
Journal of Applied Physics is the American Institute of Physics' (AIP) archival journal for significant new results in applied physics; content is published online daily, collected into two online and printed issues per month (24 issues per year). The journal publishes articles that emphasize understanding of the physics underlying modern technology, but distinguished from technology on the one side and pure physics on the other. See: http://jap.
The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world's largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.