Magnetoelectric memory cell uses less power

1 min read

A magnetoelectric random access memory (MELRAM) cell based on the stress-mediated magnetoelectric effect has been developed by a team of researchers from France and Russia. They claim the memory cell promises low bit-reading and low bit-writing energies.

According to the team, the research could aid production of devices such as instant-on laptops, close-to-zero-consumption flash drives, and data storage centres that require much less air conditioning.

Most efforts have focused on reducing the energy of the write operations in magnetic memories, since these operations typically use more energy than read operations.

"We focused on read operations in this paper because the potential for the writing energy to be very low in magnetoelectric systems means that the energy output will now be higher for read operations," said Nicolas Tiercelin, a research scientist from the Centre National de la Recherche Scientifique.

In the researchers' latest paper, they showed a combination of magnetoelastic and piezoelectric materials in a magnetoelectric memory cell could allow for read operations with extra-low energy consumption.

The core of the researchers' MELRAM memory cell is based on combining the properties of two types of materials by coupling them mechanically. Magnetic alloys – one based on a combination of terbium-cobalt and the other based on iron and cobalt – with thicknesses of a few nanometres were stacked on top of one another. The alloys form a magnetoelastic nanocomposite material whose magnetic spins react to mechanical stress.

These alloys are then placed on a piezoelectric substrate, which consists of relaxor ferroelectrics, exotic materials that change their shape or dimensions when they are exposed to an electric field.

"The nanocomposite multilayer provides strong magnetoelectric interaction at room temperature," said Vladimir Preobrazhensky, research director at the Wave Research Center, Prokhorov General Physics Institute of the Russian Academy of Sciences.

"This interaction is the basic mechanism for control of magnetic states by the electric field. This feature of the magnetoelectric memory is the origin of its extra-low power consumption."