Role of 5 mol% rare earth (La3+) on the structural, microstructural, and magnetic properties of cobalt chromite ceramics

Abstract

Spinel oxides, which have the structure AB2O4 and are distinguished by their exceptional magnetic, electric, and multiferroic properties and exhibit a wide range of functional responses in the category of oxides. The cobalt chromate (CoCr2O4) is well-known as a multiferroic-magnetoelctric (ME) material. It belongs to the magnetic spinal oxide family and is noted for its complicated spiral ferromagnetic(FM) orderings. To enhance the magnetic properties of the CoCr2O4, in this work we have chosen Lanthanum (La3+) 0.05 mol% doped cobalt chromites (CoCr2O4) nanoparticles. The solution combustion method was utilized to synthesize the nanomaterial, where urea and glucose were used as fuels. The Structural exploration of the Co0.95La0.05 Cr2O4 nanoparticles were clarified using powder X-ray diffraction. To understand the microstructure properties we have carried out high-resolution electron microscopy and it reveals highly porous nature. In FTIR spectra the two main absorption bands at 507 cm−1 and 616 cm−1 were observed which confirm the formation of spinal chromates. The TGA results revealed a slow thermal degradation, and the sample has a thermal stability that is greater than the temperature range tested. Researchers have examined the changes in temperature and magnetic field affected the magnetic properties of materials over time (ZFC & FC). In comparison to the bulk sample, the Curie temperature at which samples transition from a paramagnetic (PM) state to a collinear short-range ferromagnetic (FM) state is significantly lower. This temperature is denoted as TC-98 K deteriorated with time in terms of quality. At low temperatures, there is no magnetic transition that can be identified between the short-range FM order and the long-range spiral spin structure. This is in contrast to the magnetic transitions that can be discovered in bulk. What gives rise to all of the intriguing qualities that have been described above is the presence of weak magnetic frustration, which is very much connected to super-exchange interactions and is found along different paths such as A-O-A, B–O–B, and A-O-B. This presence is what gives rise to all of the intriguing characteristics that have been described above.