Dielectric Properties of Dual Phase (Cu-Zn-Ni-Mg-Fe)O High Entropy Oxide

A mixture of spinel and rock -salt phase was synthesized for (Cu-Zn-Ni-Mg-Fe)O HEO High Entropy Oxide (HEO) through the modified solid-state synthesis and studied for the dielectric properties. Three different (Cu-Zn-Ni-Mg-Fe)O HEO samples were synthesized by the variation of synthesis parameters, i.e., 10 hour (hr) ball -milling followed by sintering at 1050 degrees C for 20 hr (10BM-HEO-20), 20 hr ball -milling followed by sintering at 1050 degrees C for 20 hr (20BM-HEO-20) and sintering for 10 hr (20BM-HEO-10) separately. The synthesized samples were studied for the effect of synthesis parameters on phase evolution and their correlation with dielectric properties. The volume phase fraction for the spinel and rock -salt phase changed with the variation of the synthesis parameters. The value of dielectric constant decreased for the sample 10 BM-HEO-20, 20BM-HEO-20 and 20 BM-HEO-10 HEOs due to the synergistic effect of decrease in particle size, volume phase fraction of spinel phase as well as more distorted unit cells of spinel HEO phase. The value of dielectric loss is in decreasing trend for 10BM-HEO-20, 20BM-HEO-20 and 20BM-HEO-10 samples. The value of the dispersion factor for 10BM-HEO-20, 20BM-HEO-20, and 20BM-HEO-10 are found to be 1.839, 2.313, and 2.156, respectively. The present study provides insight the dielectric properties of HEO can be tuned broadly by the change in the synthesis parameters.