Synopsis: Waves That Shock Resistance

An electric field can launch shock waves that create a fast and nonvolatile resistivity change in transition-metal oxides.
Synopsis figure
Marcelo Rozenberg/Université Paris-Sud, Université Paris-Saclay

Today’s nonvolatile memories, such as flash drives, are based on conventional silicon technologies. But researchers are exploring alternative materials, like transition-metal oxides, for building faster and higher density memories. Recent experiments show that an applied electric field can induce, within a few nanoseconds, a large change in the resistivity of these oxides. This change, which is nonvolatile and reversible, could be used to store information. But current theories cannot fully explain this resistive switching behavior. Now, a study by Shao Tang at Florida State University, Federico Tesler at the University of Buenos Aires, and co-workers suggest that the effect can be initiated by ionic defects propagating like shock waves through the material.

The resistance properties of transition-metal oxides are governed by oxygen vacancies—defects in which oxygen atoms are missing from a lattice site. To model resistive switching, the authors calculated how the distribution of these vacancies evolved in a manganese oxide following the sudden application of an electric field via an electrode. The results show that the resistance change is generated via a two-step process. First, vacancies accumulated at the electrode propagate through the highly resistive electrode-material interface, creating the front of a shock wave. Second, the vacancy shock wave enters the bulk material. Since electrons move between metal atoms via the oxygen, the vacancies reduce the electron mobility. Hence as the vacancy wave leaves the interface, the macroscopic resistance of the material decreases. The model results were confirmed by experiments on a manganese-oxide device. These new insights into the microscopic mechanisms behind resistive switching may help researchers engineer better memory devices based on transition metals.

This research is published in Physical Review X.

–Matteo Rini


More Features »


More Announcements »

Subject Areas

Materials Science

Previous Synopsis

Particles and Fields

The Heavy Limit of Dark Matter

Read More »

Next Synopsis

Related Articles

Synopsis: Flexible Electronics, Heal Thyself

Synopsis: Flexible Electronics, Heal Thyself

A suspension of copper particles fixes breaks in electronic connections, providing a possible way to heal damaged circuits. Read More »

Viewpoint: Crystalline Metals Effortlessly Fit the Mold
Condensed Matter Physics

Viewpoint: Crystalline Metals Effortlessly Fit the Mold

Molding crystalline metals like silver into nanopillar structures is both possible and easier to achieve for narrower pillars, in contrast with other materials. Read More »

Viewpoint: Pushing Towards Room-Temperature Superconductivity
Condensed Matter Physics

Viewpoint: Pushing Towards Room-Temperature Superconductivity

Two independent studies report superconductivity at record high temperatures in hydrogen-rich materials under extreme pressure. Read More »

More Articles