Abstract
In this study, we measured characteristics of nickel nanowire structures whose thicknesses are 30 and 80 nm and widths are 300、600、900、1200、1500、2500 nm and continuous film. We measured its’ magnetization reversal behavior from room temperature to exceeding Curie temperature and determining the levels of its’ magnetic resistance dependence on the temperature alteration, a four-points probe system was applied to measure the magnetic resistance in the vacuum. Theoretically, saturation magnetization and exchange stiffness constant gradually decreases because of temperature increasing in the magnetic thin film and it also causes measured switching field decreasing in our research. Above the Curie temperature, its’ magnetization will destruct completely and we can’t no longer measure elements’ characteristic of magnetization reversal as a result of kinetic energy of atoms are bigger than magnetic energy of magnetons inside the structure. Our research results exhibit that single magnetic element’s switching field has two different slopes of tendencies with increasing temperature in the specific width and thickness. This issue is less measured so far. Its switching field will decrease with gradually increasing temperature in the first half of the tendency. When exceeding the specific temperature, it turns into another tendency whose switching field will increase with gradually increasing temperature. And it doesn’t measure magnetoresistance signal of the switching field anymore when temperature exceeds element’s Curie temperature. Therefore, we doubt that the magnetic thin film structures have above two magnetization reversals during heated below the Curie temperature. We change width and thickness of the magnetic structures by the phenomenon, investigating the structures’ effects of the different width and thickness are heated in magnetization reversal.