Papers by Author: Xiao Bai Chen

Abstract: 180nm-thick Ni33Fe67 and Ni21Fe79 films were deposited on SiO2/Si(100) substrates at 633 K by DC magnetron co-sputtering. Structural, electrical and magnetic properties of the films were investigated using X-ray diffraction, field emission scanning electron microscopy, a four-point probe technique and an alternating gradient magnetometer. The Ni21Fe79 film has a single bcc structure whereas the Ni33Fe67 film is a fcc-bcc mixed phase. The films grow with granular grains. The grain shape of the Ni21Fe79 film is triangular and rectangular. The Ni33Fe67 film consists of irregular shaped grains and a few large triangular grains. The grain size of the Ni21Fe79 film is larger than that of the Ni33Fe67 film. The resistivities of the Ni21Fe79 and Ni33Fe67 films are 1.82×10-63m and 1.09×10-63m. The saturation magnetization of the Ni21Fe79 and Ni33Fe67 films are 1.09×106 A/m and 1.02×106 A/m. The coercivity of the Ni21Fe79 and Ni33Fe67 films are 2.06×104 A/m and 8.84×103 A/m , respectively.

Abstract: 185 nm-thick Ni76Fe24 films were deposited on SiO2/Si(100) substrates at room temperature by DC magnetron co-sputtering and they were annealed in a vacuum of 5×10-4 Pa at 300 , 400 and 480 °C for 1 hour, respectively. The as-deposited film grows with thin columnar grains and has void networks in the grain boundaries. As the annealing temperature increases, the grain size gradually increases and the void networks decrease. Besides, the void networks shorten and widen with annealing temperature. The resistivity of the film decreases with increasing annealing temperature. The magnetic hysteresis loop of the as-deposited film shows a hard magnetization requiring a saturation field of 1050 Oe while that of the film annealed at 480 °C represents an easy magnetization. For the film annealed at 480 °C the coercivity is 78 Oe and the ratio of remanent magnetization to saturation magnetization is 0.72. The as-deposited and annealed films have an isotropic magnetization characteristic.