Capturing dual behavior of the parallel coercivity in FeNi/Cu nanowire arrays by fine-tuning of segment thicknesses

• Published in: Journal of alloys and compounds Vol. 825; p. 153992
• Main Authors: Abbas, M.H., Ramazani, A., Montazer, A.H., Kashi, M. Almasi
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 05.06.2020; Elsevier BV
• Subjects: Arrays; Aspect ratio; Coercivity; Demagnetization; Diameters; FeNi/Cu nanowire arrays; Ferromagnetism; First-order reversal curve analysis; Giant magnetoresistance; Interaction field; Magnetic properties; Magnetoresistivity; Nanowires; Parallel coercivity; Pulsed electrochemical deposition; Thickness; Thickness tuning; magnetization reversibility; Thickness tuning; FeNi/Cu nanowire arrays; first-order reversal curve; parallel hysteresis curve coercivity; FeNi segment thickness; porous aluminum oxide; Pulsed electrochemical deposition; Cu segment thickness; First-order reversal curve analysis; Parallel coercivity; Interaction field; Nanowires; multilayered NWs
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.153992

The emergence of novel effects such as giant magnetoresistance and magnetothermopower in single nanowires (NWs) and multilayered NWs (MNWs) makes it necessary to comprehensively understand and distinguish between their magnetic behavior and subtle characteristics. Herein, experimental fine-tuning of both ferromagnetic and non-magnetic segment thicknesses in 50 nm diameter FeNi/Cu MNW arrays from TFeNi = 25–260 nm and TCu = 2–23 nm, respectively, enables us to find the threshold TCu, below which the coercive field behavior of rod-like MNW systems magnetically saturated parallel to their long axis shows a continuous decreasing trend, which is similar to that of single NWs with integrated structure. This is in turn accompanied with enhanced magnetizing- and demagnetizing-type interactions as evidenced by first-order reversal curve (FORC) analysis. FORC measurements of disk-shaped to rod-like FeNi segments also indicate a transition from dipolar to monopolar interaction regime which coincides with continuous increasing and decreasing trends of the parallel coercivity and magnetization reversibility, being in agreement with typical MNW magnetic characteristics. Our results on the variation behavior of interaction field distribution as a function of TCu allows for evaluating the credibility of the theoretical approach proposed in the literature on the interaction field, providing threshold conditions based on the segment aspect ratio of MNW arrays. [Display omitted] •FeNi/Cu MNW arrays with fine-tuned TFeNi = 25–260 nm and TCu = 2–23 nm were fabricated.•Composition and crystalline properties were not influenced by thickness tuning of MNWs.•Parallel coercivity showed a dual behavior as a function of TFeNi for varied TCu.•For TCu<6 nm, magnetic characteristics of MNWs were similar to those of single NWs.•FORC analysis evidenced a transition from dipolar to monopolar interaction regime.