LAUSR

Abstract Co-doped La2NiMnO6 (La2CoxNi1-xMnO6, LCxNMO, x = 0.1-0.5) ceramics were fabricated at relatively low temperature of 700 °C, to obtain double-perovskite with remarkable magnetic performance. It was found that the LCxNMO ceramics in P21/n and R-3 phases could be well densified, with high relative density (>99 %) and fine grain size (0.5−1 μm). An increasement in cell volume was observed with the doping of Co, and the valence state changed from (Mn3+ + Ni3+/Co3+) to (Mn4+ + Ni2+/Co2+), revealing the improvement of B-site cations ordering. Moreover, the smaller grains resulted from the lower sintering temperature also decreased the level of antisite disordering. Consequently, the value of MS/Mtheo was significantly improved from 75.49% to 88.36 % by optimizing Co-doping concentration while the Curie temperature was still rather high (>250 K). The LC0.5NMO ceramic was found to have the maximum MS (4.86 μB/f.u.), attributing to the large B-site ordering because of higher Mn4+ and Ni2+/Co2+ content.