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

Publication date: Available online 14 February 2016
Source:Thin Solid Films
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 −10mA/cm² for over 3500s revealed no obvious decay in current density, suggesting good stability under typical working conditions in a photoelectrochemical device.