Controllable preparation and tunable magnetic anisotropy of amorphous LaxM1−xOy (M=Mn, Fe) nanowire arrays.

Two LaxMn1−xOy (LM1, LM2) and three LaxFe1−xOy (LF1, LF2, LF3) amorphous nanowire arrays (NWAs) were prepared by chemical co‐precipitation in anodic aluminium oxide (AAO) templates. The concentration of the reactant plays a crucial role in determining the morphology of LaxMn1−xOy NWAs. The AAO template was etched using a mixed nitrate solution that led to the exposure of LaxFe1−xOy NWAs on the template surface in the process of preparation, then the length of nanowires exposed to the template depends on the etching time. The LM2 NWAs exhibited obvious magnetic anisotropy after the template is almost eliminated by etching with NaOH solution, while the magnetic anisotropy of LaxFe1−xOy NWAs was manipulated by the length of nanowires outside the template. There is a regular change in the coercive force Hc and remanence ratio Mr/Ms with increasing length of nanowires outside the template. Therefore, the nanoarray materials with tunable magnetic anisotropy were obtained by controllable preparation, and they can be applied to high‐density magnetic memory nano‐devices. [ABSTRACT FROM AUTHOR]