Thermal analysis of laser annealed garnet film as determined by bubbles statics

A thermal analysis of laser annealed channels as deduced from the change of bubbles statics after heat treatment is presented in (YLa)3Fe5-zGazQ12garnet films. The profiles of the thermal processes in the laser annealed channels are determined from the comparison with data we have obtained after usual annealing in furnace. Strong changes of bubbles parameters after furnace annealing and laser annealing are detected. An increase of the collapse field with the quenching temperature is observed in agreement with calculation performed from the Néel molecular field theory [1] and the Van Erk thermodynamic equilibrium model which described the cations distribution between the octahedrai and tetrahedral sites of the garnet [2]. From the collapse field profile from the center of a laser annealed channel and data deduced from furnace annealing experiment, it has been possible to determine the quenching temperature profile of such a channel for different applied laser powers. At high laser power a saturation in the quenching effect is observed and can be discussed from the corresponding very short relaxation time of the cation at high equilibrium temperature.