Structural and magnetic properties of Sc1.1Fe3.9Al8 alloy

Abstract: The crystallochemical and magnetic nature of ternary Sc1+δ Fe4−δ Al8 intermetallic with a small Sc excess δ=0.1 was investigated by scanning electron microscope, X-ray powder diffraction, neutron diffraction, Mössbauer effect and superconducting quantum interference device techniques. The sample crystallizes in a tetragonal ThMn12 type structure. The excess of Sc atoms substitute Fe at the (8f) positions and have a pronounced effect on the magnetic properties. The experiments carried out in temperature range 4–320K show that below 120K the magnetic structure of the alloy forms a double cycloid with magnetic moments rotating according to the incommensurate in-plane wave vector, which is temperature independent up to 160K. The value of Fe magnetic moment is close to 0.9μB atom−1 at 4K. Temperature dependence of unit cell dimensions can be explained within the Debye–Grüneisen approximation. [Copyright &y& Elsevier]