Room temperature ferromagnetism of nonmagnetic element Ca-doped LiNbO3 films

Abstract:

The nonmagnetic element Ca-doped LiNbO₃ films were prepared on Si (111) substrates by radio frequency (RF) magnetron sputtering technique. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) indicate that the Ca atoms enter the LiNbO₃ lattice in the form of Ca²⁺ ions. Superconducting quantum interference device (SQUID) results show that the Ca-doped LiNbO₃ films have room-temperature ferromagnetism and a maximum saturation magnetization of 4800 A/m at the 3% of Ca atom doping concentration. The room temperature ferromagnetism of the Ca-doped LiNbO₃ films can be attributed to the occurrence of vacancies due to Ca doping and is the intrinsic property.