講演情報
[11p-E214-12]Elucidation of the local magnetic structure in all-optical switching Heusler compounds
〇Phillip David Bentley1, Songtian Li2, Tetsuro Ueno3,2, Ryuji Itakura1, Yoshiyuki Ohtsubo4, Kenta Amemiya5, Yoshinori Kotani6, Seiji Sakai2 (1.Kansai Institute for Photon Science, QST, Kizugawa 619-0215, 2.Takasaki Institute for Advanced Quantum Science, QST, Takasaki 370-1292, 3.Synchrotron Radiation Research Center, QST, Sayo 679-5148, 4.NanoTerasu Center, QST, Sendai 980-8579, 5.Photon Factory, KEK, Tsukuba 305-0801, 6.JASRI, Sendai 980-8579)
キーワード：
Heusler compounds、All-optical switching、XMCD
Mn-based cubic ferrimagnetic Heusler compounds such as Mn2RuGa (MRG), which show all-optical switching (AOS) are promising candidate for femtosecond (fs) and low powered optically driven magnetic random-access memory (OD-MRAM) due to their high spin polarization, robust perpendicular magnetic anisotropy (PMA), and low saturation magnetization (Ms). AOS in these materials depends on the compensation temperature (Tcomp) of the material being around room temperature, the point where the moments of the Mn atoms antiparallel coupled two one another on two different lattice sites cancel each other out (Ms = 0). Tcomp depends on this delicate balance of moments within the compound as seen in MRG thin films of varying Ru concentration. Whilst MRG shows AOS, its varying spin polarization and weak PMA limit its potential use within OD-MRAM. If we dope this alloy with Fe, it may be possible to enhance the PMA and improve the spin polarization. However, critical to the optimisation of these alloys is an understanding of the local magnetic structure within these materials and how their magnetic properties evolve as a function of temperature. In this study, we examine the effect of Fe doping in MRG thin films by exploring the local magnetic structure via synchrotron X-ray magnetic circular dichroism (XMCD) where we show that doping with Fe raises Tcomp and modifies the magnetic properties of these MRG thin films. We also show that we can create stoichiometric Mn2FeRuGa (MFRG) thin films which are expected to be highly spin polarized but also have a compensation temperature near to or above room temperature. Finally we explore the magnetic ordering within these thin films as well as subtle differences between the MCD spectra measured via total-electron yield (TEY) and X-ray excited optical luminescence (XEOL).