Email this article Doping-induced temperature evolution of a helicoidal spin structure in the MnGe compound
- Authors: Altynbaev E.V.1,2, Sukhanov A.S.1,2, Siegfried S.3, Dyadkin V.A.1,4, Moskvin E.V.1,2, Menzel D.5, Heinemann A.3, Schreyer A.3, Fomicheva L.N.6, Tsvyashenko A.V.6, Grigoriev S.V.1,2
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Affiliations:
- Konstantinov Petersburg Nuclear Physics Institute
- Physical Department
- Helmholtz Zentrum Geesthacht
- Swiss-Norwegian Beamlines at the ESRF
- Technische Universitat Braunschweig
- Institute for High Pressure Physics
- Issue: Vol 10, No 4 (2016)
- Pages: 777-782
- Section: Article
- URL: https://journals.rcsi.science/1027-4510/article/view/189295
- DOI: https://doi.org/10.1134/S1027451016040224
- ID: 189295
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Abstract
The helicoidal magnetic structure of a MnGe compound doped with 25% Fe is studied by means of small-angle neutron scattering in a wide temperature range of 10–300 K. Analysis of the scattering-function profile demonstrates that magnetic structures inherent to both pure MnGe and its doped compounds are unstable. The doping of manganese monogermanide is revealed to lead to higher destabilization of the magnetic system. In passing from MnGe to Mn0.75Fe0.25Ge, the magnetic-ordering temperature TN decreases from 130 to 95 K, respectively. It is demonstrated that, at temperatures close to 0 K, the intensity of the contribution to scattering from stable spin helices decreases and the intensity of scattering by spin helix fluctuations increases with increasing impurity-metal concentration. An increased intensity of anomalous scattering caused by spin excitations existing in the system is observed. Helicoidal fluctuations and spin excitations corresponding to low temperatures indicate the quantum nature of the instability in the doped compound. However, MnGe doping with Fe atoms has no influence on the compound’s magnetic properties at temperatures of higher than TN. The temperature range of short-range ferromagnetic correlations is independent of concentrations and is restricted by temperatures T ranging from 175 to 300 K.
About the authors
E. V. Altynbaev
Konstantinov Petersburg Nuclear Physics Institute; Physical Department
Author for correspondence.
Email: evgeniy.alt@lns.pnpi.spb.ru
Russian Federation, Leningrad oblast, 188300; St. Petersburg, 198504
A. S. Sukhanov
Konstantinov Petersburg Nuclear Physics Institute; Physical Department
Email: evgeniy.alt@lns.pnpi.spb.ru
Russian Federation, Leningrad oblast, 188300; St. Petersburg, 198504
S.-A. Siegfried
Helmholtz Zentrum Geesthacht
Email: evgeniy.alt@lns.pnpi.spb.ru
Germany, Geesthacht, 21502
V. A. Dyadkin
Konstantinov Petersburg Nuclear Physics Institute; Swiss-Norwegian Beamlines at the ESRF
Email: evgeniy.alt@lns.pnpi.spb.ru
Russian Federation, Leningrad oblast, 188300; Grenoble, 38000
E. V. Moskvin
Konstantinov Petersburg Nuclear Physics Institute; Physical Department
Email: evgeniy.alt@lns.pnpi.spb.ru
Russian Federation, Leningrad oblast, 188300; St. Petersburg, 198504
D. Menzel
Technische Universitat Braunschweig
Email: evgeniy.alt@lns.pnpi.spb.ru
Germany, Braunschweig, 38106
A. Heinemann
Helmholtz Zentrum Geesthacht
Email: evgeniy.alt@lns.pnpi.spb.ru
Germany, Geesthacht, 21502
A. Schreyer
Helmholtz Zentrum Geesthacht
Email: evgeniy.alt@lns.pnpi.spb.ru
Germany, Hamburg, D-20095
L. N. Fomicheva
Institute for High Pressure Physics
Email: evgeniy.alt@lns.pnpi.spb.ru
Russian Federation, Troitsk, Moscow, 142190
A. V. Tsvyashenko
Institute for High Pressure Physics
Email: evgeniy.alt@lns.pnpi.spb.ru
Russian Federation, Troitsk, Moscow, 142190
S. V. Grigoriev
Konstantinov Petersburg Nuclear Physics Institute; Physical Department
Email: evgeniy.alt@lns.pnpi.spb.ru
Russian Federation, Leningrad oblast, 188300; St. Petersburg, 198504
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