Enhanced magnetic properties of La2MgxNi1-xMnO6 bulks prepared at a low temperature

Abstract

La2MgxNi1-xMnO6 (LMxNMO) bulks with different Mg doping contents (x = 0–0.40) were originally fabricated at a low temperature (700 °C). All samples exhibited a highly dense microstructure and a small grain size. A structural transition from the P21/n phase to the R-3 phase was indicated by XRD analysis of LMxNMO bulks with augmented Mg doping. XPS results showed that, on account of the Mg doping, the Mn4+/Mn3+ ratio was significantly increased, which was the main factor in determining the degree of B-site ordering. The magnetic performances of LMxNMO were obviously enhanced by optimizing Mg doping content. Among all the samples, LM0.1NMO bulk had the highest B-site ordering and a lower disorder degree, which lead to it also having the maximum Ms value (47.3 emu/g, a value which demonstrates a 25% improvement compared with non-doped LNMO). Meanwhile, the high Curie temperatures of LMxNMO bulks were attributed to the heightened density and refined grain.