A comprehensive study of microstructures and soft magnetic properties of amorphous Co66Fe4Mo2Si16B12 tape wound core

The microstructures and soft magnetic properties of Co66Fe4Mo2Si16B12 amorphous tape wound core were systematically investigated. The phase composition and corresponding structure evaluation of Co66Fe4Mo2Si16B12 amorphous ribbon after annealing at various temperatures were identified firstly. In particular, at 758 K the microstructure of the ribbon is primarily composed of Co2B, Fe2B and beta-Co phases. With the temperature approaching to 768 K, the new phases alpha-Co and CoSi appears. When the temperature increases to 778 K, the mixed phase combination of alpha(Co) + beta(Co) + Co2B + Fe2B + CoSi exists along with an apparent nano-crystallization. The soft magnetic properties of tape wound core assembled by Co66Fe4Mo2Si16B12 amorphous ribbon were then studied at annealed temperature from 713 K to 753 K. At 723 K, we found the permeability is highest with a maximum value of mu(m) = 1.675 x 10(3), and the coercive force is lowest with a minimum value of 0.134 Oe. The magnetization curve and the hysteresis loop of established tape would core annealed at 713-753 K remain almost unchanged. Finally, the relation between frequency and magnetic permeability and quality factor were carefully examined at different annealing temperatures.