The use of thermomagnetometry to follow reactions of thin films.

Thermomagnetometry (TM) is a useful technique to follow the appearance or disappearance of a magnetic phase. Even at relatively low magnetic field gradients, much greater sensitivity can be obtained with TM compared to conventional thermogravimetry (TG). This is demonstrated by following the oxidation and subsequent reduction of Co thin films on sapphire or silicon using dynamic heating and a small permanent magnet. Similarly the reaction of Co and Si is followed with this technique in an inert or reducing atmosphere. Isothermal oxidation at saturating magnetic fields provides a better defined situation than for the unsaturated conditions as well as a more sensitive experimental method to study the oxidation of Co.