Stephen, A. and Rossi, F. and Nasi, L. and Ferrari, C. and Ponpandian, N. and Ananth, M.V. and Ravichandran, V.
(2008)
Induced ordering in electrodeposited nanocrystalline Ni–Mn alloys.
Journal Of Applied Physics, 103 (5).
053511-1.
ISSN 0021-8979
Abstract
The Ni3Mn type of ordering in nanocrystalline NiMn films with different compositions prepared by
electrodeposition was investigated by using x-ray diffraction, differential scanning calorimetry
�DSC�, thermogravimetric analyzer, Mössbauer spectroscopy, and transmission electron
microscopy. The investigations reveal the existence of composition-induced Ni3Mn-type ordering in
the as-deposited film of 76.2 at. % Ni. The atomic disorder is characterized by an exothermic effect
in DSC. An analysis of the broad exothermic transition reveals the stages of phase transformation
leading to ordering. The Curie temperatures of the alloys were determined from thermomagnetic
measurements, the maximum value obtained for the ordered sample. Mössbauer spectroscopy at
room temperature reveals ordered �ferromagnetic� and disordered �paramagnetic� phases in the
as-deposited films. Superlattice reflections observed in selected area electron diffraction pattern for
the 76.2 at. % Ni film alone further support the observation of composition-specific atomic
ordering.
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