Large magneto-elastic anisotropy enhancement with temperature in composition-graded FeCoTa thin films

Abstract

Static and dynamic magnetic properties of composition-graded FeCoTa thin films were systematically studied with respect to temperature and the deposition power of Ta target. The magnetic anisotropy field and ferromagnetic resonance frequency were found to be increased with the increasing of deposition power of Ta target due to the enhancement of stress when Ta concentration is increased. Thermal stability of the films shows a very interesting behavior with a peculiar and large increasing of magnetic anisotropy with temperature when the deposition power for Ta is moderate while it exhibits normal decreasing with temperature when the deposition power is low or high. The results are discussed and explained in terms of the magneto-elastic anisotropy contribution when the stress of the films is varied. © 2013 AIP Publishing LLC.