High performance PrFeB-type nanocomposite ribbons with high B concentration

摘要

Several means have been applied for increasing the magnetic properties of the PrFeB-type nanocomposites with high boron concentration (≥ 10 at%). A slight substitution of the refractory elements (i. e. Ti, Zr, Nb and V) for Fe was found very effective in suppressing the formation of metastable Pr_2Fe_(23)B_3 and Fe_3B phases, leading to the presence of large amount of Pr_2Fe_(14)B and α-Fe phases of fine grain size, which resulted in the drastic improvement of the magnetic properties. Furthermore, incorporating C with refractory elements Nb or Zr is beneficial in improving the coercivity of Pr_2(Fe, Nb)_(23)(B, C)_3 (Pr_(7.14)(Fe, Nb)_(82.14)(B, C)_(10.72)) and Pr_2(Fe, Zr)_(23)(B, C)_3 ribbons, but not for Pr_2(Fe, Ti)_(23)(B, C)_3. Finally, the magnetic properties of B_r = 9.9 kG, _iH_c = 8.0 kOe and (BH)_(max) = 18.7 MGOe can be achieved in (Pr_(0.75)Nd_(0.25))_(8.5)Fe_(79.5)Ti_2B_(10), while the highest coercivity of _iH_c = 13.2 kOe (B_r - 8.8 kG and (BH)_(max) = 16.3 MGOe) are obtained in Pr_(9.5)Fe_(78.5)Ti_2B_(10).