Structure, magnetic and magnetocaloric properties of the Mn5Ge3 thin film grown on Si(111).

Mn₅Ge₃ is a ferromagnetic hexagonal crystal promising for spintronics and magnetocalorics. A systematic study and analysis of the magnetic properties of the Mn₅Ge₃ thin film grown on Si(111) were performed. The magnetic anisotropy of the film is determined by the shape anisotropy and the easy magnetization axis aligned along the c axis of the crystal. The uniaxial anisotropy constant K_u fully corresponds to that for a bulk single crystal, which indicates that c axis coincides with film normal. Mn₅Ge₃ film demonstrates high saturation magnetization M_S = 900 emu/cm³ (900 kA/m) at T = 100 K and magnetocaloric effect ΔS = 3.16 ± 0.22 J kg⁻¹ K⁻¹ at 300 K and B = 1.5 T. ΔS is comparable to that for multicomponent or Gd rare earth films. Furthermore, a different anisotropy of the magnetocaloric effect compared to bulk Mn₅Ge₃ was found, which may be related to the anisotropy of the film shape and, possibly, to the domain structure. The results obtained are promising for the design and development of magnetocaloric, spintronic, and spin-caloritronic devices on a silicon platform. [ABSTRACT FROM AUTHOR]