Electron spin relaxation in CMR manganites: Absence of critical acceleration

V. A. Atsarkin, V. V. Demidov, F. Simon, R. Gaal, Y. Moritomo, K. Conder, A. Jánossy, L. Forró

Research output: Contribution to journalConference article

15 Citations (Scopus)

Abstract

Using original modulation technique, the longitudinal electron spin-lattice relaxation time T1 has been measured in a series of nearly cubic La1-xCaxMnO3 (x = 0.1; 0.2; 0.25; 0.33) and layered La2-2xSr1+2xMn2O7 (x = 0.4 and 0.5) manganites both in paramagnetic state and around the temperature (Tc) of the magnetic ordering. The data are compared with the evolution of the transverse relaxation time T2 as determined from the ESR linewidth. Well above Tc, the T1 = T2 equality is confirmed, whereas a pronounced slowing down of T1 is observed in all the materials as Tc is approached. The temperature dependence of T1 is found to be consistent with that of Tχ(T), where χ(T) represents the temperature dependence of the electron-spin susceptibility determined from the ESR absorption area. The interpretation suggests freezing the local field fluctuations due to polarization of superparamagnetic clusters in the external magnetic field.

Original languageEnglish
Pages (from-to)256-258
Number of pages3
JournalJournal of Magnetism and Magnetic Materials
Volume258-259
DOIs
Publication statusPublished - Mar 1 2003
EventSecond Moscow International Symposium on Magnetism (MISM) - Moscow, Russian Federation
Duration: Jun 20 2001Jun 24 2001

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Keywords

  • Critical phenomena
  • Electron spin resonance
  • Manganites
  • Spin relaxation

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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