Study on the soft magnetic properties and high frequency characteristics of Co-M (M = Ti, Zr, and Hf) thin films

Abstract

Soft magnetic properties and high frequency characteristics of Co100-xMx (M = Ti, Zr, and Hf) thin films have been investigated. All M-doped Co100-xMx films exhibit strong induced in-plane uniaxial magnetic anisotropy. With the increase of the x, the 4πMs and coercivity along the hard and easy axes (Hch and Hce) are decreased, while Hk reaches the maximum value for the films having the composition to become the fully amorphous. Among them, less Hf or Zr content, i.e., x = 7, are sufficient in forming the Co100-xMx amorphous, in contrast, more Ti content, i.e., x = 15, should be needed. The optimal properties of 4πMs = 11.0 kG, Hce = 5.4 Oe, Hch = 4.0 Oe, Hk = 320 Oe and fFMR = 5.2 GHz for Co93Hf7 films and 4πMs = 11.7 kG, Hce = 6.1 Oe, Hch = 1.6 Oe, Hk = 266 Oe and fFMR = 4.9 GHz for Co93Zr7 films can be obtained.