Nature Materials published an online research paper titled Amorphous phase-change memory alloy with no resistance drift on Oct 1.

In the paper, the Materials Innovation Design Center (CAID) team at the State Key Laboratory for Mechanical Behavior of Materials at Xi'an Jiaotong University (XJTU) analyzed the atomic-scale mechanism of structural relaxation behavior in amorphous phase-change materials.

It clarifies that the root cause of resistance drift mainly comes from the evolution of amorphous local structural defect density and Peierls distortion with time and temperature. With this in mind, the team designed a chromium telluride amorphous alloy CrTe3 in which almost all local structures are perfect octahedra.

In this octahedral structure, there is no obvious difference between long and short bonds, so its structural relaxation is very weak and does not trigger changes in the band structure, which can eliminate resistance drift.

Subsequently, the team prepared CrTe3 thin films by magnetron sputtering, and confirmed that the amorphous thin film has no obvious resistance drift in a wide temperature range from -200 to 165 C.

Furthermore, the team cooperated with Researcher Song Zhitang's team from the Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, to verify that the CrTe3 device still has no obvious resistance drift behavior after 100,000 operations.

In addition, the team realized stable multi-value storage through photo-controlled electrical measurement methods and designed, and processed an intelligent car based on a CrTe3 array, realizing a stable automatic addressing function.

Even if the CrTe3 array is subjected to a temperature of 150 C for one hour, the automatic addressing function can still be reproduced afterwards. This innovative design of phase-change memory materials fundamentally solves the resistance drift problem of phase-change memory devices, providing a key material carrier for the development of high-precision phase-change neuromorphic devices.