In this work we report on the study of magnetization reversal in zero dimensional nickel nanodots patterned using a novel polymer based soft lithography technique. The nanodots, having their easy axis of magnetization normal to the plane of the sample, were characterized by in situ MFM observations, performed under varying magnetic fields to understand the magnetization reversal process. The average demagnetization curve of the sample was obtained from the MFM images. The results compare well with the demagnetization curve obtained from vibrating sample magnetometer (VSM) measurements. Further, the angular dependence of in-plane magnetization reversal process was investigated by studying the magnetization data obtained from the VSM performed at different angles of field orientation with respect to the sample.

The effect of an external magnetic field with a flux density of 0.2 T and different configurations relative to the plane of the sample (normal‐to and in‐plane) on the nucleation and growth of CoFe nanostructures has been investigated. CoFe nanostructures were grown on N‐type Si (111) substrate using an e‐beam evaporation system. The samples were subjected to an external magnetic field of 2 T normal‐to and in‐plane to the plane of the samples during the growth period. The influence of the magnetic field on the morphology of the CoFe nanostructures was studied using atomic force microscopy and scanning electron microscopy. Significant changes in the structural characteristics due to the influence of the magnetic fields were evident. Further, the influence of the external magnetic field on the magnetic properties of the materials was analyzed using a vibrating sample magnetometer (VSM) and the composition of the samples was analyzed using energy dispersive X‐ray spectrometry. These results indicate that the easy axis of magnetization in both the samples (normal‐to and in‐plane) is along the direction of the applied magnetic field.

Evolution of coercivity and its angular dependence in CoFe nanostructures subjected to field cooling has been investigated in this work. Spherical CoFe grains with an average diameter of 30 nm were grown on a silicon substrate using electron beam evaporation. Further, the as-deposited sample was subjected to field cooling. The morphology and topography of the sample before and after field cooling were characterized by atomic force microscopy and SEM. Magnetic force microscopy indicated that there is a good uniformity of magnetization throughout the sample after field cooling. Vibrating sample magnetometer measurements indicate that the coercivity in CoFe nanostructures is dependent on shape of the nanostructures.

Effects of nitrogen annealing on structural and magnetic properties of Co/Si (100) up to 700 • C has been studied in this paper. Ultrathin Co films having a constant thickness of 50 Å were grown on Si (100) substrates using electron-beam evaporation under very high vacuum conditions at room temperature. Subsequently, the samples were annealed at temperatures ranging from 100-700 • C in a nitrogen environment at atmospheric pressure. Sample quality and surface morphology were examined using atomic force microscopy. Silicide formation and the resultant variation in crystallographic arrangement were studied using X-ray diffractometer. The magnetization measurements done using a vibrating sample magnetometer indicate a decrease in coercivity and retentivity values with increase in annealing temperature. Resistivity of the samples measured using a four-point probe set up shows a decrease in resistivity with increase in annealing temperature. Formation of various silicide phases at different annealing temperatures and the resultant variation in the magnetic susceptibility has been thoroughly studied and quantified in this work.