Annealing influence on the Gilbert damping parameter and the exchange constant of CoFeB thin films

作者：Conca A^*; Papaioannou E Th; Klingler S; Greser J; Sebastian T; Leven B; Loesch J; Hillebrands B

来源：Applied Physics Letters, 2014, 104(18): 182407.

DOI：10.1063/1.4875927

We present a study of the influence of the annealing temperature T-a on the magnetic properties of Co40Fe40B20 thin films. Using a vector network analyzer ferromagnetic resonance (VNA-FMR) setup and the magneto-optical Kerr effect, the dependence of the Gilbert damping parameter alpha, the exchange constant A, the saturation magnetization as well as the coercive field and the Kerr signal on T-a is reported. Additionally, the correlation with the crystalline properties of the films studied by X-ray diffractometry is discussed. We found that while the damping parameter alpha and the coercive field show sharp changes starting at a certain T-a value, the exchange constant A and the Kerr signal show a steady evolution. A differential modification of the film surface compared to the bulk is discussed as a possible reason. In any case, we found that the low damping values are preserved at the first onset of crystallization.

• 出版日期2014-5-5