Magnetic viscosity in iron-rhodium nanowires

JULIETA S. RIVA; G. POZO LÓPEZ; ADRIANA CONDÓ; JORGE LEVINGSTON; LUIS FABIETTI; SILVIA URRETA

JOURNAL OF ALLOYS AND COMPOUNDS

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2017 vol. 709 p. 531 - 531

0925-8388

oble/transition bimetallic nanowires of nominal composition Fe90Rh10 are AC electrodeposited into 20 nm diameter hexagonally self-assembled alumina nanopores. Nanowires about 18 nm in diameter and 1 mm long are polycrystalline and multiphase. Wires contain a-Fe grains and very small grains of the ClCs-type a0-Fe(Rh) phase. The room temperature magnetization mechanism and the thermal stability of nanowire magnetic configurations are further investigated by measuring the dependence of the coercive field on the applied field sweeping rate R. From these data a mean fluctuations field value of m0HFR ¼ (9.0 ± 0.5) mT is obtained (at coercivity) and an effective activation magnetic moment mac ¼ 5400 mB is estimated, with mB the Bohr magneton. At the coercive field (about 45 mT) the resulting activation lengths become lAC z 6.4 and 6.7 nm for a-Fe and a0-Fe(Rh), respectively. Assuming an effective magnetic anisotropy, considering magnetostatic shape contributions in addition to the magnetocry