Magnetic properties of microwave-processed ferromagnetic La2CoMnO6

Abstract

We synthesized ferromagnetic La2CoMnO6 by irradiating a stoichiometric mixture of oxide powder with microwave (MW) of frequency 2.45 GHz and studied the impact of microwave power (P) on its structural and magnetic properties. The MW power (P) was varied from 1000 to 1600 W at a pre-set sintering temperature of 1200 °C and a dwelling time of 20 min. The ferromagnetic transition temperature and saturation magnetization depend on P. The highest saturation magnetization value of 5.54 μB/f.u. was realized in the sample irradiated with P = 1400 W which is closer to the theoretical value of 6 μB/f.u. for spin-only contributions from Co2+ (S = 3/2) and Mn4+ (S = 3/2). The observed results can be attributed to varying degrees of B-site ordering of Co2+ and Mn4+ ion with the MW power, however, caution has to be taken to ensure that the sample is maintained at a specified temperature for the desired dwelling time. Our results indicate that varying the microwave power at a fixed sintering temperature provides a different approach for manipulating saturation magnetization and Curie temperature.