Aging properties of spinel‐type high‐entropy oxides (Co.2Cr.2Fe.2Mn.2Zn.2)3O4 for thermistors

Abstract

AbstractHerein, a spinel‐type high‐entropy ceramics (Co.2Cr.2Fe.2Mn.2Zn.2)3O4 is introduced. The obtained ceramics exhibit superior thermal stability under accelerated aging conditions at 125°C for 500 h, that is, aging drift was less than .35% for all samples sintered at temperatures (1200or–1275or . The variation of resistance is mainly attributed to the oxidation of grain boundaries and the migration of oxygen vacancies. The relationship between crystal structure evolution and aging properties was investigated using structural analysis and P–V–L bonding theory. Theoretically, the Co/Cr/Mn/Fe–O bonds at the octahedral sites in the spinel structure are more important for controlling structural stability.