Template-assisted electroplating of Sm-Co composite nanowires: Issue of boric acid additive via R-D process

Abstract

A considerable number of Sm-Co nanowires were synthesized in anodic aluminum oxide (AAO) by electroplating in aqueous solutions. To ensure a uniform Sm composition ratio, the electroplating was conducted using linear sweep voltammetry method. Dispersed Sm-Co nanowires were synthesized via a combination of annealing for densification and template etching. Subsequently, a low-temperature reduction and diffusion process was performed at 700 ℃ in a facile way using NaCl, KCl, and Ca granules. The one-dimensional structure morphology was maintained; however, contrary to expectations, the hysteresis loop in the VSM did not exhibit the excellent magnetic properties of the Sm2Co17 hard ferromagnet. Analysis by XPS, XRD, and TEM revealed that the addition of boric acid during electroplating suppressed the transformation of Sm-Co nanowires into the Sm2Co17 phase. The use of boric acid as an additive when synthesizing nanowires by electroplating using an AAO template has been found to be beneficial for a highly ordered morphology; however, this may lead to undesirable issues in the reduction and diffusion process, and thus should be carefully considered.