The influence of applied tensile stress on power loss in Co-rich amorphous Co-Fe-Si-B ribbons with induced magnetic anisotropy

The influence on power loss P T of applied tensile stress σ in amorphous (Co 0.89 Fe 0.11 ) 72 Mo 3 Si 15 B 10 ( \lambda_{s} > 0 ) and Co 73 Mo 2 Si 15 B 10 ( \lambda_{s} < 0 ) ribbons with different induced magnetic anisotropy K u is reported. The losses are measured under sinusoidal flux conditions at f = 50 Hz, J_{\max} = 0.57 T and at f = 400 Hz, J_{\max} = 0.10 T. Measurements are carried out on samples in a stress-relieved state and with magnetic anisotropies induced by stress or field annealing. At f = 50 Hz, a minimum m P t versus σ is observed. The σ-value ( \sigma_{\min} ) corresponding to the minimum P T increases with increasing |K u |. At f = 400 Hz, a minimum in P T versus σ is observed in the samples with induced magnetic anisotropy, whereas \sigma_{\min} = 0 in the stress-relieved samiales. However, no correlation between and \sigma_{\min} and K u is possible from the present data.