Fe-79wt%Ni合金超细微粒的压力效应

Pressure Effect of Fe79wt% Ni Alloy Ultrafine Particles

用蒸发冷凝法制备了不同平均粒径的Ｆｅ７９ｗｔ％Ｎｉ合金超细微粒样品。在不同压强Ｐ下，将其压制成圆片及小圆环。随成形压强Ｐ增大，比饱和磁化强度σｓ明显增大，达最大值后，略有减少；矫顽力Ｈｃ呈线性下降。复数磁导率实部μ１及损耗正切ｔｇδ随Ｐ而变化。μ１及ｔｇδ的压力效应与平均粒径ｄ密切相关。

Fe79wt% Ni alloy ultrafine particles with various average size were prepared by the evaporationcondensation method. They were compressed into disks and small rings under different pressures. As the forming pressure P increased specific saturatuin magnetization σs increased markedly. Having risen to the greatest data, specific saturation magnetizaton σs fell down a little, while coercive force Hc exhibited a linear decrease. The real part μ1 of the complex permeability and the tangent of loss angle tgδ changed with the forming pressure P. There was a close relationship between the forming presure effect and average size d.