Growth, magnetic properties, and Raman scattering of La2NiMnO6 single crystals

Millimeter size single crystals of double-perovskite La2NiMnO6 were grown by the high-temperature solution growth method. The magnetic measurements and polarized Raman spectra between 5 and 350 K provide evidence that the crystals have a high degree of Ni2+/Mn4+ ordering, a small amount of lattice defects, and the highest Tc=288 K reported so far for ferromagnetic double perovskites. At a microscopic level, the crystals are heavily twinned, and the effect of twinning on the Raman spectra is analyzed in detail.