Influence of annealing temperature on microstructure and magnetic properties of Ti/Ni/Ti thin films

Ti(3nm)/Ni(10nm)/Ti(3nm) films were deposited directly on glass substrates using dc facing-target magnetron sputtering system at room temperature and in situ-annealed from room temperature(RT) to annealing temperature(Ta) 500 degrees C, respectively. At Ta = 400 degrees C, the gain size was about 15 nm, and the magnetic domains of the films distributed homogenously, and the magnetic domain cluster size was nearly 25 nm. The maximum perpendicular coercivity of Ti(3nm)/Ni(10nm)/Ti(3nm) films was 1360 Oe. The segregation or diffusion of Ti and the stress anisotropy played important roles to increase the coercivity. The intergrain interaction of films was obtained by delta M plots. In annealing films, X-ray diffraction (XRD) profiles showed two diffraction peaks of NiTi monoclinic structure (002), (111) lattice orientations.