Investigation of variety of valence metal ions combinated novel Co‐rich high entropy oxides and its magnetic properties and microstructure

Abstract

In this work, a series of five spinel-structured oxides were synthesized using a straightforward and effective solid-state methodology. Departing from the conventional design concept, we opted for the substitution of Fe3 + with five metal cations, all possessing trivalent average valence states and equivalent proportions. X-ray diffraction, scanning electron microscope, energy spectrum analyzer, vibrating sample magnetometer were used to detect the phase, micro-structure, element distribution, magnetism of the samples, respectively. The test results show that samples have the spinel structure (Fd3(_)m), and the element composition and distribution are the same as expected. The test results of magnetic properties reveal that these five samples exhibit the properties of soft magnetic materials. The maximum adjustment range of saturation magnetization (Ms) is increased from 23.5 emu/g to 34.8 emu/g by adjusting the elemental composition. Besides, the maximum adjustment range of coercivity (Hc) is increased from 11 Oe to 60 Oe. Furthermore, these materials exhibit a low remanent magnetization ratio, indicating that high-entropy oxides with spinel structures are highly sensitive to changes in an applied magnetic field. The high-entropy oxide is a new material with great prospect. It creates new possibilities for the design of magnetic materials.