Magnetisation reversal at elevated temperatures in Co/Pt multilayer thin films

In this paper we report upon a study of the magnetization reversal mechanisms in Co/Pt thin films at elevated temperatures. An alternating gradient force magnetometer has been modified in order to perform measurements at elevated temperatures. The data obtained from hysteresis loops and remanence curves measured at high temperature has been used to analyse reversal mechanisms which are discussed in terms of a well established two-coercivity model. The high sensitivity of the magnetic measurements reveal subtle temperature dependent changes in the magnetic characteristics of the films, which are attributed to thermally induced modifications of the energy barriers to magnetization reversal and film microstructure. The evolution of domain structure during reversal has been examined by magnetic force microscopy for a sample placed in varying remanent states at elevated temperatures and is found to correlate with the two-coercivity model. Additionally, a method by which samples may be demagnetized in situ at elevated temperatures is discussed along with domain wall motion induced by the stray field from magnetic force microscope tips.