Mn-based Heusler Compounds with Low Magnetization*

Heusler compounds with small or zero magnetization are of interest for spintronics applications, because they cause little or no fringing fields and may exhibit ultrafast dynamics and high spin polarization [1-3]. We find virtually zero room-temperature magnetizations in stoichiometric Ru₂MnSn and Pt₂MnGa Heusler alloys fabricated by rapid quenching from the melt. X-ray diffraction patterns show the formation of a L2₁ structures with a = 6.22 Å and a tetragonal structure with a = 4.02 Å and c = 7.24 Å in Ru₂MnSn and Pt₂MnGa, respectively. Both systems show nearly linear M(H) curves for intermediate field strengths of several T, and the slopes dM/dH are used to characterize the spin structure. In Pt₂MnGa, which shows a helical spins structure with an ordering temperature of about 350 K [4], dM/dH increases with decreasing spiral wave vector q. The complex spin structures of Ru₂MnSn and Pt₂MnGa are used to explain the electron-transport properties of the alloys.

References
[1] W. Zhang et al., J. Phys. D 51, 255001 (2018).
[2] M.E. Jamer et al., Phys. Rev. Appl. 7, 064036 (2017).
[3] A. Hirohata et al., J. Phys. D 50, 443001 (2017).
[4] S. Singh et al., Nat. Comm. 7, 12671 (2016).