Soft magnetic peculiarities of the electroless magnetic loss CoFeB films

Electroless CoFeB films with good soft magnetic properties were fabricated on poly-ester plastic substrate from sodium tartarate as complexing agent. The plating rate of electroless CoFeB films is a function of concentration of sodium tetrahydroborate, pH of the plating bath, plating temperature and the metallic ratio. The estimated regression coefficient b0–3, confidence interval, residual error r and confidence interval rint were confirmed by computer program. The optimal composition of the plating bath was obtained and the dynamic electromagnetic parameters of films were measured in the 2–10 GHz range. At 2 GHz, the μ′, μ″ of the electroless CoFeB films are 304 and 76.6, respectively, as the concentration of reducer is 1 g L−1. Magnetic hysteresis loop of deposited CoFeB films shows a remanence close to the saturation magnetization and coercivity of about 0.7–1.6 Oe. The loops along the hard axis display low anisotropic field Hk of 30–45 Oe.