Angular dependence of interactions in polycrystalline Co nanowire arrays

Ordered Co nanowire arrays with a constant georrietry (similar to 40 nm diameter, similar to 10 mu m length and similar to 100 nm interwire distance) were ac pulse electrodeposited into anodic aluminum oxide template under different deposition current densities (5.31, 7.08 and 8.85 mA/cm(2)). Microstructure and magnetic properties of the samples were studied using X-ray diffraction (XRD) pattern, selected area diffraction (SAED) pattern and first-order reversal curve (FORC) diagrams. SAED patterns showed inhomogeneous polycrystalline structure along the length of a nanowire. FORC diagrams revealed two-phase magnetic behavior in which soft and hard magnetic phases related to triplet cobalt crystalline directions. Despite the fact that angular dependence of hysteresis loops provides information about magnetization reversal, angular FORC offers additional information on the magnetostatic and interphase interactions depending on angle between the field and nanowires axis (alpha). Different magnetic behaviors were seen by change in alpha; interacting two-phase behavior in alpha = 0 degrees which reduced to a non-interacting behavior for alpha > 60 degrees may be attributed to reduce delay in magnetization reversal of two phases. Increasing the reversible portion of the major hysteresis loop in alpha = 90 degrees is a possible source of difference between the hard to soft ratio obtained from FORC diagrams and XRD patterns. (C) 2015 Elsevier B.V. All rights reserved.