Anantharaman, M R; Lisha, R; Hysen, T; Geetha, P; Avasthi, D K; Ramanujan, R V(IOP Publishing LTD, March 7, 2014)
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Abstract:
Metglas 2826 MB having a nominal composition of Fe40Ni38Mo4B18 is an
excellent soft magnetic material and finds application in sensors and memory
heads. However, the thin-film forms of Fe40Ni38Mo4B18 are seldom studied,
although they are important in micro-electro-mechanical systems/nano-electromechanical
systems devices. The stoichiometry of the film plays a vital role in
determining the structural and magnetic properties of Fe40Ni38Mo4B18 thin
films: retaining the composition in thin films is a challenge. Thin films of 52 nm
thickness were fabricated by RF sputtering technique on silicon substrate from a
target of nominal composition of Fe40Ni38Mo4B18. The films were annealed at
temperatures of 400 °C and 600 °C. The micro-structural studies of films using
glancing x-ray diffractometer (GXRD) and transmission electron microscope
(TEM) revealed that pristine films are crystalline with (FeNiMo)23B6 phase.
Atomic force microscope (AFM) images were subjected to power spectral
density analysis to understand the probable surface evolution mechanism during
sputtering and annealing. X-ray photoelectron spectroscopy (XPS) was
employed to determine the film composition. The sluggish growth of crystallites
with annealing is attributed to the presence of molybdenum in the thin film. The
observed changes in magnetic properties were correlated with annealing induced
structural, compositional and morphological changes