Temperature Dependence of Domain-Wall Creep in Pt/CoFe/Pt Films

The temperature dependence of the magnetic domain-wall creep behavior is examined in Pt/CoFe/Pt films with perpendicular anisotropy. The domain-wall creep behavior is monitored by a magneto-optical Kerr effect microscope equipped with a cryostat, which enables us to control the temperature from the ambient temperature down to 85 K. It is found that the domain-wall speed under a fixed magnetic field is decreased exponentially proportional to the inverse of the temperature, which can be explained as a typical behavior of the thermally activated process. By measuring the field-dependent domain-wall speed, we confirm that the domain-wall creep theory is valid with the value of the creep exponent 1/4, over the temperature range we examine.