Magnetostructural phase transition in electroless-plated Ni nanoarrays

Journal Article · Wed Jun 01 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3594692· OSTI ID:21538413

Huang, Chun-Chao; Lo, Chih-Chieh; Tseng, Yuan-Chieh; Liu, Chien-Min; Chen, Chih ^[1]

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1. Department of Materials Science and Engineering, National Chiao Tung University 1001, Ta Hsueh Road, Hsin-Chu 30010, Taiwan (China)

Ni nanoarrays were synthesized by electroless-plating and shaped by an anodic aluminum oxide template. The as-plated arrays exhibited superparamagnetic (SM) ordering resulting from nanocrystalline microstructure. Ferromagnetic (FM) ordering was found to be restored as the arrays' crystallinity was enhanced upon post-annealing. The microstructure (crystallinity) and the FM ordering are strongly coupled, revealing a magneto-structural correlation for the arrays. The magnetostructural properties of the arrays can be controlled by post-annealing, where the magnetization is proportional to the annealing temperature. The electroless-plated arrays synthesized in this work display magnetic anisotropy not found in electroplated ones. This is likely attributed to the nature of the clusterlike microstructure, whose cluster-boundaries may confine the FM rotation within the cluster. The spin-polarization was probed by x-ray magnetic circular dichroism while the arrays underwent the SM{yields}FM phase transition. The sum-rules results reveal that the total magnetization of the arrays is dominated by spin moment (m{sub spin}). The change in m{sub spin} is responsible for the SM{yields}FM phase transition upon annealing, as well as for the loss of magnetization upon temperature increase that we observed macroscopically.

• OSTI ID: 21538413
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 11; Other Information: DOI: 10.1063/1.3594692; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ALUMINIUM OXIDES
ANISOTROPY
ANNEALING
CORRELATIONS
CRYSTAL STRUCTURE
CRYSTALS
FABRICATION
FERROMAGNETIC MATERIALS
MAGNETIC CIRCULAR DICHROISM
MAGNETIC MOMENTS
MAGNETIZATION
MICROSTRUCTURE
NANOSTRUCTURES
NICKEL
PHASE TRANSFORMATIONS
POLARIZATION
SPIN ORIENTATION
SUM RULES
SUPERPARAMAGNETISM
X RADIATION
ALUMINIUM COMPOUNDS
CHALCOGENIDES
DICHROISM
ELECTROMAGNETIC RADIATION
ELEMENTS
EQUATIONS
HEAT TREATMENTS
IONIZING RADIATIONS
MAGNETIC MATERIALS
MAGNETISM
MATERIALS
METALS
ORIENTATION
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
TRANSITION ELEMENTS