Effect of Mg~(2+) on the Magnetic Compensation of Lithium-Chromium Ferrite

摘要

Mg-substituted ferrite Li_(0.5)Mg_xFe_(1.25-(2/3)x)Cr_(1.25)O_4 (0 ≤ x ≤ 0.3) was studied using X-ray diffraction, Moessbauer spectroscopy and magnetic measurements. X-ray diffraction patterns show that all samples have cubic spinel structure. The temperature-dependent magnetic measurements revealed that the compensation point T_K of Li_(0.5)Fe_(1.25)Cr_(1.25)O_4 starts to approach the Neel temperature T_N as Mg~(2+) substitution of Fe~(3+) increases, until the compensation disappears at x = 0.3. This effect is investigated in relation to the cation distribution established using the Moessbauer study of this system.