Magnetic order and magnetotransport in half-metallic ferrimagnetic MnyRuxGa thin films
File Type:
PDFItem Type:
Journal ArticleDate:
2021Access:
openAccessCitation:
Siewierska K.E., Atcheson G., Jha A., Esien K., Smith R., Lenne S., Teichert N., O'Brien J., Coey J.M.D., Stamenov P., Rode K., Magnetic order and magnetotransport in half-metallic ferrimagnetic MnyRuxGa thin films, Physical Review B, 104, 6, 2021Download Item:
2012.05736.pdf (PDF) 1.592Mb
Abstract:
The ruthenium content of half-metallic Mn2RuxGa thin films, with a biaxially strained inverse Heusler structure, controls the ferrimagnetism that determines their magnetic and electronic properties. An extensive study of MnyRuxGa films on MgO (100) substrates with 1.8≤y≤2.6 and x=0.5, 0.7 or 0.9, including crystallographic, magnetic order, magneto-transport, and spin polarization, is undertaken to map specific composition-dependent properties in this versatile ternary system. A comparison of experimental densities obtained from x-ray reflectivity with calculated densities indicates full-site occupancy for all compositions, which implies chemical disorder. All moments lie on a Slater-Pauling plot with slope 1 and all except x=0.5, y=2.2 exhibit magnetic compensation at Tcomp below 500 K. The coercivity near Tcomp exceeds 10 T. Increasing the Mn or Ru content raises Tcomp, but increasing Ru also decreases the spin polarization determined by point contact Andreev reflection. Molecular-field theory is used to model the temperature dependence of the net ferrimagnetic moment and three principal exchange coefficients are deduced. Marked differences in the shape of anomalous Hall and net magnetization hysteresis loops are explained by substantial canting of the small net moment by up to 40∘ relative to the c axis in zero field, which is a result of slight noncollinearity of the Mn4c sublattice moments due to competing intrasublattice exchange interactions arising from antisite disorder and excess Mn in the unit cell. Consequences are reduced-spin polarization and an enhanced intrinsic contribution to the anomalous Hall effect. The systematic investigation of the physical properties as a function of x and y will guide the selection of compositions to meet the requirements for magnonic and spintronic MRG-based devices.
Sponsor
Grant Number
Irish Research Council (IRC)
GOIPG/2016/308
Marie Curie
713567
Science Foundation Ireland (SFI)
16/USC2C/3287
Science Foundation Ireland (SFI)
16/IA/4534
Science Foundation Ireland (SFI)
12/RC/2278
Author's Homepage:
http://people.tcd.ie/stamenphttp://people.tcd.ie/atchesog
http://people.tcd.ie/rodek
http://people.tcd.ie/jcoey
Description:
PUBLISHEDType of material:
Journal ArticleCollections:
Series/Report no:
Physical Review B104
6
Availability:
Full text availableKeywords:
Ferrimagnetism, Half-metals, Heusler alloy, Thin films, Magnetization measurements, Mean field theory, Resistivity measurements, Sputtering, X-ray diffractionSubject (TCD):
Nanoscience & Materials , Neuroscience , FABRICATION , NANOSTRUCTURES , Nanotechnology , PhysicsDOI:
https://doi.org/10.1103/PhysRevB.104.064414ISSN:
24699969 24699950Licences: