Structural characteristics, magnetic properties of Re2NiMnO6 (Re = La, Pr, Nd, Sm, Y) thin films on (001) LaAlO3 by simple polymer assisted deposition

Re2NiMnO6 (Re = La, Pr, Nd, Sm, Y) epitaxial thin films grown on (001) LaAlO3 substrates were obtained via a simple polymer assisted deposition method. The XRD θ/2θ scans, ω scans, and φ scans indicate that the films are single-phase epitaxial films. It is found that there is a ferromagnetic (FM) transition with the temperature decreasing from room temperature for all the films. The Raman mode positions shift toward the low frequency with the substitution of La by a smaller rare earth element. The FM transition temperature Tc decreases as the A-site ionic radius decreasing. Moreover, all the FM transition temperatures (Tc) of the Re2NiMnO6 films are lower than those corresponding values of the bulks, indicating the ferromagnetic interaction weakening. It is suggested that the ferromagnetic interaction is affected by the strain existing in the film through affecting the B(B′)O6 octahedra and the cation disorder related to the ionic radius of Re, which can be used as an effective way to improve the magnetic properties of the film and obtain the higher Tc functional materials.