Thickness dependence of domain wall energy in Fe-Ni thin films

• Main Authors: Liou, Shang-sheng, 劉尚昇
• Other Authors: Jen Shien-uang
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/52137723979331992897

碩士 === 輔仁大學 === 物理學系 === 84 === The application of Fe-Ni thin films as computer memory and logic elements isvery valuable and has been studied extensively in recent years. For the composition of Fe20Ni80, also known as Permalloy, it is the most remarkableone. With the method of thermal evaporation, we have made Fe-Ni thin films invarious thickness ranges and in neighboring compositions around that of Permalloy for domain observation and other experiments. The thickness of thin films was determined by Dektak3, a depth profile measuring system. The real composition of thin films was measured with SEM-EDS(Scanning Electron Microscopy - Energy Dispersive X-ray Spectrometer). The observation of domain structure and domain walls in thin films was made by the Bitter pattern method. From experimental data and theoretical calculations, we have studied the thickness and composition dependence of domain wall energy respectively. It wasfound that the domain wall energy density of Fe-Ni thin films is about 1-20 erg/cm2. For the case of Permalloy, our experimental data about the film thickness dependence of domain wall energy are in agreement with that from theoretical predictions. In the case of other compositions, the minimum value of domain wall energy is around the composition of Permalloy.