Influence of the sluggish diffusion effect on stability by analyzing the Cr diffusion behavior in (CoCrFeMnNi)3O4 films

Abstract

Introducing the concept of high entropy in functional materials is a promising way to improve the stability, but the mechanism of its influence has rarely been discussed in detail. In this work, (CoCrFeMnNi)₃O₄ spinel films were prepared by the alloy oxidation method. The effect of sputtering power on the structure, electrical properties, and electrical stability of films was investigated. The results showed that the increase of ion energy during sputtering promotes grain growth resulting in the decrease of resistivity. The selective oxidation and kinetically controlled oxidation during oxidation process caused the gradient distribution of Cr³⁺, which affected the sluggish diffusion effect and further lead to the better electrical stability of the films. Notably, the fastest Cr³⁺ diffusion rate had the highest disorder of the Cr³⁺ distribution in the 30 W films, whose resistivity drift rate under accelerated aging at 125°C for 400 h is reduced from 9.67% to 1.05%. This work provided a research case for improving the electrical stability of manganese-based spinel films by the sluggish diffusion effect and the scientific basis for high stability electronic devices fabrication.