Influence of Substrate Roughness on Magnetic Properties of Permalloy /Glass

• Main Author: 黃正偉
• Other Authors: 盧志權
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/49760019699830465015

碩士 === 國立臺灣師範大學 === 物理學系 === 101 === Magnetic properties of NiFe (permalloy, Py) film on glass was studied as function of the roughness of glass substrate. These films were fabricated by Magnetron sputtering on HF etching glass and the thickness of the Py film is fixed 5nm. The roughness was controlled and examined by etching time and AFM, respectively. Cover glass was sed as the substrate which was etched by soaking in 15% HF(Hydrogen Fluoride) solution to produce the roughness. Different states of surface roughness were controlled by the HF etching time up to 15 min. The surface morphology was examined by Atomic force microscopy (AFM), and hence average roughness, root mean square roughness and skewness were obtained for all samples. MOKE was used to measurement the magnetic hysteresis of the sample, while spin dynamics were characterized by a Vector Network Analyzer based ferromagnetic resonance (FMR) spectrometer. Therefore, squareness of hysteresis loop, saturation field, coercivity and damping constant can be analyzed as function of the roughness of Py film.There is no obvious change in root mean square roughness as the etching tike was increased. The minimum and maximum roughnesses were found to 0.25 and 3.75 nm at etching times of 0min and 3mins, respectively. In contrast, skewness was lineally proportional to the etching time. The magnetic properties, such as coercivity, FMR half-line width, have no clearly dependence on root mean square height. However, the dependence of these magnetic parameters on skewness was found. Coercivity showed an inverse V-shpae relationship with increasing skewness that the maximum coercivity of 20Oe is at skewness of 1.5. The FMR resonant field and line width at half maximum height exhibited oscillating behavior as skewness was increased. The periodicity of skewness of this oscillation was about 2.