Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7988488 | Intermetallics | 2016 | 8 Pages |
Abstract
We report the effect of post-annealing on the crystalline phase, grain growth, magnetic and mechanical properties of Ni-Mn-Ga thin films deposited at room temperature followed by post-annealing at different temperatures. The phase and microstructural analysis reveal that amorphous to crystalline transformation occurs in as-deposited films after post-annealing above 873Â K. The transformation of disordered phase into nanocrystalline phase by the influence of annealing has been confirmed by transmission electron microscopy. The crystalline films exhibit soft magnetic behavior with the Curie temperature of 314Â K, while the amorphous films exhibit the Pauli-paramagnetic behavior even down to 4Â K. The mechanical properties like hardness and elastic modulus of the films also show a strong dependence on the annealing temperature with crystalline film exhibiting maximum values of 6Â GPa and 103Â GPa, respectively. The Ni-Mn-Ga film annealed at 873Â K exhibits enhanced nanomechanical properties and room temperature ferromagnetism which make this a potential candidate for use in MEMS devices.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
S. Vinodh Kumar, R.K. Singh, M. Manivel Raja, A. Kumar, S. Bysakh, M. Mahendran,