Temperature dependence of domain‐wall coercive field in magnetic garnet films

The coercive properties of magnetically uniaxial liquid‐phase epitaxy garnet films were investigated between 10 K and the Neel temperature (TN≤500 K). Two independent methods, the results of which are nearly identical (magnetical response of oscillating domain walls and the method of coercive loops measured in a vibrating sample magnetometer), were used. Besides the usual domain‐wall coercive field, Hdw, the critical coercive pressure, pdw, was also introduced as it describes in a direct way the interactions of the domain walls with the wall‐pinning traps. Both Hdw and pdw were found to increase exponentially with decreasing temperature. Three different types of wall‐pinning traps were identified in the sample and their strength, their rate of change with temperature, and their temperature range of activity were determined.