(07B521) Structure and magnetic properties of Pr_(10)(Fe,Co,Ni)_(84)B_6 nanocomposite alloys

摘要

Nanocomposite ribbons with composition Pr_(10)(Fe,Co,Ni)_(84)B_6 (x = 0.0, 0.05, 0.10, and 0.15) were prepared by melt-spinning. All melt-spun ribbons are composed of a fine mixture of 2:14:1 and bcc-(Fe,Co,Ni) phases with an additional soft phase (Pr_2Fe_(23)B_3-based) for x = 0.10 and 0.15. The room temperature coercivity decreases from 7.4 to 2 kOe with Co and Ni substitutions likely due to the decrease of the magnetocrystalline anisotropy of the 2:14:1 phase and the increase of the amount of the soft phases. Saturation magnetization increases slightly while remanence and (BH)_(max) show a slight decrease for x up to 0.10 and then they drop quickly. The intergranular exchange coupling is strong for x ≤ 0.10 but it is reduced significantly for x = 0.15 due to the substantial increase of the volume and size of the soft phases. Thermomagnetic measurements showed a significant increase of the Curie temperature of the 2:14:1 phase from 290 °C for x = 0 to 485 °C for x = 0.15. High temperature hysteresis loop measurements showed improved temperature dependence of remanence and coercivity for x = 0.05.