Anomalous spin relaxation and quantum criticality in Mn1 − xFexSi solid solutions

• Published in: JETP letters Vol. 100; no. 1; pp. 28 - 31
• Main Authors: Demishev, S. V., Samarin, A. N., Glushkov, V. V., Gilmanov, M. I., Lobanova, I. I., Samarin, N. A., Semeno, A. V., Sluchanko, N. E., Chubova, N. M., Dyadkin, V. A., Grigoriev, S. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.09.2014
• Subjects: Atomic; Biological and Medical Physics; Biophysics; Condensed Matter; Molecular; Optical and Plasma Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Quantum Information Technology; Solid State Physics; Spintronics; JETP Letter; Electron Spin Resonance; Spin Relaxation; Electron Spin Resonance Line; Electron Spin Resonance Measurement
• ISSN: 0021-3640; 1090-6487
• DOI: 10.1134/S0021364014130025

We report results of the high frequency (60 GHz) electron spin resonance (ESR) study of the quantum critical metallic system Mn 1 − x Fe x Si. The ESR is observed for the first time in the concentration range 0 < x < 0.24 at temperatures up to 50 K. The application of the original experimental technique allowed carrying out line shape analysis and finding full set of spectroscopic parameters, including oscillating magnetization, line width and g factor. The strongest effect of iron doping consists in influence on the ESR line width and spin relaxation is marked by both violation of the classical Korringa-type relaxation and scaling behavior. Additionally, the non-Fermi-liquid effects in the temperature dependence of the ESR line width, which may be quantitatively described in the theory of Wölfle and Abrahams, are observed at quantum critical points x * ∼ 0.11 and x c ∼ 0.24.