Coercivity of nanoporous Ni produced by dealloying

摘要

Nanoporous Ni specimens with the ligament lengths of 10-210 nm were produced by the dealloying of Ni_(0.25)Mn_(0.75) alloy and annealing at 473-873 K. The coercivity (H_c) increased with increasing ligament length (L) up to 50 nm, and decreased with increasing L above 50 nm. At L<50 nm, the size dependence of H_c for nanoporous Ni is lower than that for nanocrystalline Ni. The low size dependence of H-c is discussed on basis of a random anisotropy model.