Correlation between local structure and magnetic behavior in co-sputtered TbxFe73Ga27−x (7 ≤ x ≤ 11) thin films

We report on the evolution of the microstructure of Tb-Fe-Ga films deposited by co-sputtering from Tb33Fe67 and Fe72Ga28 targets. The sputtering power was fixed (90 W) in the Fe72Ga28 whereas it was increased from 50 to 90 W in the Tb33Fe67 target resulting on TbxFe73Ga27−x layers with 7 ≤ x ≤ 11. The local structure was determined by means of x-ray absorption fine structure spectroscopy at Fe-K, Ga-K and Tb-L3 edges. The increase of Tb in the alloy promotes the phase segregation that produces a larger amount of the TbFe2 structural phase. The structural results have been correlated with the magnetic characterization that shows the enhancement of the out-of-plane component of the magnetization.