Heat-Assisted Magnetization Reversal Using Pulsed Laser Irradiation in Patterned Magnetic Thin Film With Perpendicular Anisotropy

Cooling velocity of patterned Tb-Fe film with a lateral size of 50 times 50 mum² was experimentally investigated for the application to heat-assisted writing operation in high-density magnetic random access memories. The patterned Tb-Fe film was heated-up by using pulsed YAG laser irradiations with the duration of 1 ns which is realizing a semi-adiabatic heating process. The ratio of magnetization reversal in the patterned Tb-Fe film was estimated by measuring an anomalous Hall voltage. The main results are as follows: (1) Magnetic field required for magnetization reversal of Tb-Fe film was decreased from 1.4 kOe to 200 Oe by applying the heat-assisted magnetization reversal method. (2) Cooling velocity of patterned Tb-Fe film can be estimated by using pulsed magnetic fields with various time delays from the pulsed laser irradiation. (3) With increasing the thermal conductivity coefficient of electrical leads, the velocity to cool the patterned Tb-Fe film increased.