Spin Fluctuations and a Spin-Fluctuation Phase Transition in the Magnetically Ordered Phase of Manganese Monosilicide

• Published in: JETP letters Vol. 115; no. 11; pp. 673 - 678
• Main Authors: Demishev, S. V., Samarin, A. N., Karasev, M. S., Grigoriev, S. V., Semeno, A. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.06.2022; Springer Nature B.V
• Subjects: Atomic; Biological and Medical Physics; Biophysics; Condensed Matter; Electron paramagnetic resonance; Magnetic variations; Manganese; Molecular; Optical and Plasma Physics; Particle and Nuclear Physics; Phase transitions; Physics; Physics and Astronomy; Polarons; Quantum Information Technology; Single crystals; Solid State Physics; Spintronics; Transition temperature
• ISSN: 0021-3640; 1090-6487
• DOI: 10.1134/S0021364022600677

A manganese monosilicide (MnSi) single crystal has been studied by the high-frequency (60 GHz) electron paramagnetic resonance method. The most currently detailed temperature dependences of the linewidth and g -factor have been obtained in the temperature range of 2–40 K. They indicate that a spin fluctuation transition occurs in the spin-polarized phase of МnSi, formed by magnetic polarons in a magnetic field of B ~ 2 T at K. This transition corresponds to change in the regime of magnetic fluctuations at a temperature much lower than the transition temperature T c ~ 30 K from the paramagnetic phase existing at T > T c to the magnetically ordered phase occurring at T < T c . This result extends the region of applicability of the concept of spin fluctuation transitions, which were previously considered only for magnetic states without long-range magnetic order. A model for the description of the electron paramagnetic resonance parameters in the system of magnetic polarons has been discussed.