Role of 5 mol% Mg-Ni on the Structural and Magnetic Properties of Cobalt Chromates Crystallites Prepared by Solution Combustion Technique

TheCo(1 - (x + y))Mg(x)Ni(y)Cr(2)O(4)(where, x = y = 0.00, 0.05) nanoparticles were synthesized by the solution combustion technique using a mixture of carbamide and glucose as fuel. The refined XRD study confirmed that samples are single-phased with spinel cubic structure having space group Fd3m. The difference in ionic radius of Co(2+)ions and Mg2+, Ni(2+)ions resulted in the reduction in lattice parameters. The stretching vibration modes are found at tetrahedral and octahedral site by using FTIR spectra. Force constant value also estimated from FTIR spectra. The magnetic transition was studied by using temperature-dependent magnetization. The magnetic transitions such as ferrimagnetism transition were observed at Curie temperature (T-C = 98 K, 91 K for x = y = 0.00, 0.05, respectively), and spiral spin transition was observed at spiral temperature (T-S = 26 K, 17 K for x = y = 0.00, 0.05, respectively). Both samples show higher magnetization below spiral transition temperature (T-S).