Compositionally graded Fe_(1−x)-Pt_(x) nanowires produced by alternating current electrodeposition into alumina templates

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• 作者：Ali Fardi-Ilkhchy^a ; Farzad Nasirpouri^a ; ^{Nasirpouri@sut.ac.ir" class="auth_mail" title="E-mail the corresponding author} ; ^{f_nasirpouri@yahoo.com" class="auth_mail" title="E-mail the corresponding author} ; Cristina Bran^b ; Manuel Vá ; zquez^b
• 关键词：FePt ; Nanowires ; AC electrodeposition ; SEM ; TEM ; VSM
• 刊名：Journal of Solid State Chemistry
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：244
• 期：Complete
• 页码：35-44
• 全文大小：3804 K

文摘

Fe_(1−x)-Pt_(x) (0<x<1) compositionally graded nanowires (50 nm in diameter and 1 µm in length) were fabricated by alternating current (AC) electrodeposition into nanoporous aluminum oxide templates through a systematic approach. The effect of AC electrodeposition parameters such as frequency, voltage and electrolyte concentration on morphology and chemical composition of Fe-Pt alloy nanowires was studied. Based on experimental data, AC sine wave deposition at an intermediate voltage of 12 V_rms and a frequency of 50 Hz, produces nanowires with nearly stoichiometric composition (Fe₄₂Pt₅₈) and a reasonably good uniformity of pore filling. However, there is a gradual change of composition in Fe-Pt alloy nanowires along the length under certain AC parameters. The observed dependency of alloy composition on the deposition voltage and frequency of AC electrodeposition is explained by an interplay between reduction potentials and diffusion coefficients of Fe and Pt ions which makes FePt system able to access compositionally graded nanowires. Magnetic measurements of nanowires of as-deposited nanowires confirm that maximum coercivity of 1.55 kOe is observed for nearly stoichiometric composition which increases up to 1.81 kOe after thermal annealing at 550 °C.