Structural and multifunctional properties of magnetron-sputtered Fe–P(–Mn) thin films

Publication date: 31 March 2016
Source:Thin Solid Films, Volume 603
Author(s): P. Decker, H.S. Stein, S. Salomon, F. Brüssing, A. Savan, S. Hamann, A. Ludwig
Structural and magnetic properties of magnetron-sputtered Fe–P(–Mn) thin films with compositions around the Fe2P single phase region are reported, revealing the compositional range of the Fe2P-type structure and the change of the magnetic properties within this composition spread. The structural analysis shows that in order to obtain crystalline Fe–P phases the P content must be higher than (Fe0.97Mn0.03)2.33P. A maximum phase fraction of the Fe2P-type structure is obtained in the examined (Fe0.97Mn0.03)1.78P sample. The hysteresis loops for the Fe2P(–Mn) thin films show a two-step magnetic reversal with one part belonging to an amorphous phase fraction and the other to the Fe2P(–Mn) phase. A maximum coercivity of 0.36T was measured for the Fe2P(–Mn) phase fraction also at the composition of (Fe0.97Mn0.03)1.78P. Furthermore, electrochemical properties of FeP2(–Mn) thin films as hydrogen evolution catalysts (HER) are studied. FeP2(–Mn) shows a HER onset potential about 200mV lower than that of Pt. Chronoamperometric testing at −11.5mA/cm² for over 3500s revealed no obvious decay in current density, suggesting good stability under typical working conditions in a photoelectrochemical device.