2026-09-30T21:32:28Zhttps://skemman.is/oai/request

oai:skemman.is:1946/354902020-10-02T08:55:12Zcom_1946_2064com_1946_2057col_1946_2178

Háskóli Íslands Björn Áki Jósteinsson 1996- Unnar Bjarni Arnalds 1976- Magnetic behaviour of five bi-layer V2O3/Ni thin film samples sputtered on sapphire, Al2O3, were investigated using MOKE (magneto-optic Kerr effect). Three samples show a fourfold symmetry in coercivity with very small but similar change in magnetic remanence. For comparison micromagnetic simulations were done in Mumax3. The samples have a well defined growth direction, [111], so simulations were setup to replicate this. Nickel is a cubic crystal with easy axes <111>, hard axes <100> and medium axes <110>. In the simulations an external magnetic field was applied and then rotated in-plane as was done in the MOKE measurements. The result are hysteresis loops as a function of azimuthal angle yielding the normalized magnetic remanence and coercive field. This was done for two sample sizes with number of cells in x-, yand z- direction 128x128x2 and 256x256x2 both having cell size 4x4x10nm. The results did not change when sample size was increased. These simulations were done both for growth direction [111] and [100] out of plane. Quantitatively the results from simulations agree with magneto-crystalline energy for nickel, both when rotated around [111] and [100], showing a sixfold and fourfold symmetry respectively. The measured samples don’t show this sixfold symmetry. 2020-05-20T14:53:39Z 2020-05-20T14:53:39Z 2020-05-20T14:53:39Z 2020-05-20T14:31:32Z 2020-05 http://hdl.handle.net/1946/35490 en Verkfræðileg eðlisfræði Micromagnetic modelling and magneto-optical characterization of Ni/V2O3 hybrid structures Thesis Bachelor's