Eur. Phys. J. B 45, 97-102 (2005)
https://doi.org/10.1140/epjb/e2005-00168-5

Influence of Ni content on the microstructure and magnetic and magneto-optical properties of sputtered (Co_1-xNi_x)Pt₃ alloy films

¹ Instrumental Analysis Center, Shanghai Jiaotong University, 1954 Huashan Road, Shanghai 200030, China
² Shanghai Institute of Metallurgy, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China
³ Department of Physics, Hanyang University, Seoul 133-791, Korea

Corresponding author: ^a zqzou@sjtu.edu.cn

Received: 15 February 2005
Published online: 16 June 2005

Abstract

Influence of Ni content on the microstructure and magnetic and magneto-optical (MO) properties of sputtered (Co_1-xNi_x)Pt₃ alloy films has been investigated by means of Kerr spectrometer, Kerr hysteresis looper, X-ray diffractometer (XRD), and atomic force microscopy (AFM). On the whole, the addition of Ni to the CoPt₃ alloy film simultaneously decreases the Curie temperature T_C and the Kerr rotation angle , but the decrease of T_C with Ni content is more visible. When the Ni content x is increased from 0 to 0.33, T_C decreases from 273 °C to 233 °C, whereas the decrease of is quite limited and the film still preserves a strong perpendicular magnetic anisotropy (PMA) and a high coercivity, indicating that the (Co_1-xNi_x)Pt₃ alloy film with x=0.33 can be used for practical MO applications. Further increase of Ni content decreases the significantly and destroys the PMA. XRD and AFM studies show that adding a small amount of Ni in the CoPt₃ alloy film will promote the growth of grains and roughen the film surface, and thus enhance the coercivity of the film. We observe also that both the coercivity and PMA are not sensitive to the (111) preferred orientation of the (Co_1-xNi_x )Pt₃ alloy films.