Magnetic states of nickel nanogranular films were studied in two distinct structures of individual and agglomerated granules electrodeposited on n-type Si(1 1 1) surface from a modified Watts bath at a low pH of 2. Magnetic force microscopy and micromagnetic simulations revealed three-dimensional out-of-plane magnetic vortex states in stand-alone hemispherical granules and their arrays, and multi-domain patterns in large agglomerates and integrated films. Once the granules coalesce into small chains or clusters, the coercivity values increased due to the reduction of inter-granular spacing and strengthening of the magnetostatic interaction. Further growth leads to the formation of a continuous granulated film which strongly affected the coercivity and remanence. This was characterized by the domain wall nucleation and propagation leading to a stripe domain pattern. Magnetoresistance measurements as a function of external magnetic field are indicative of anisotropic magnetoresistance (AMR) for the continuous films electrodeposited on Si substrate.
Bibliographical noteFunding Information:
Student financial supports from Iranian Nanotechnology Initiative and Research Affairs of Sahand University of Technology are acknowledged. This work was supported in part by the Russian Ministry of Education and Science , the Scientific Fund of Far Eastern Federal University, and the Joint Research Program by the National Research Foundation of Korea ( 2013K2A1A7076318 ) and the Russian Foundation for Basic Research ( 14-02-91701 ).
- Magnetic domains
- Magnetic particles
- Magnetization reversal
- Vortex state
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics