Structure and magnetic properties of Ni_(0.11)Zn_xCo_(0.03)Fe_(2.86-x)O_4 ferrite films deposited on Ag-coated glass substrates by wet chemical method

摘要

Ni_(0.11)Zn_xCo_(0.03)Fe_(2.86-x)O_4 spinel ferrite films with x = 0.00,0.23,0.34,0.43 and 0.51 were prepared on Ag-coated glass substrates from nitrate and dimethylamine borane solution at 80 ℃. The Ni_(0.11)Zn_xCo_(0.03)Fe_(2.86-x)O_4 ferrite films are singe-phased spinel ferrite. With the Zn content x increasing from 0 to 0.51, the lattice constant of the ferrite films increases from 0.8383 to 0.8425 nm. The Ni_(0.11)Zn_(0.51)Co_(0.03)Fe_(2.35)O_4 film is about 500 nm thick and composed of uniform equiaxed granules of about 40-50 nm. The Raman spectrum analysis indicates that the Zn~(2+) ions occupy the A sites. Saturation magnetization increases with x increasing from 0 to 0.35, reaches a maximum value of 460 kA/m at x = 0.35, and then decreases with further increase of x. Coercivity decreases monotonically from 12.3 to 1.7 kA/m with x increasing from 0 to 0.51. The change in magnetic properties may be explained by the decrease of A-B interactions and the anisotropy constant due to the incorporation of nonmagnetic Zn~(2+) ions.