NMR Measurements of Power-Law Behavior in the Spin-Wave and Critical Regions of Ferromagnetic EuO

Abstract

Precision continuous-wave NMR measurements have been carried out over the entire magnetization curve of EuO and are presented in tabular form. Two very closely spaced resonances are observed and are attributed to domain and domain-wall signals. Both of the signals are useful for analysis in the spin-wave region. Only the domain signal is measurable above approx. 50K. The latter is used for fitting T(c) and the critical exponent Beta. The critical-region fits agree with previous measurements, within experimental error. The low-temperature data exhibit a clear-cut T(2) behavior, at variance with the expectations of conventional spin-wave theory. This result is discussed in relation to two semi-empirical spin-wave schemes, one formulated by N. Bykovetz, and one by U. Koebler. The NMR signal at 4.2K gives no indication of a quadrupole splitting, in contradiction to the interpretation of several previous spin-echo NMR spectra observed in EuO. This issue remains unresolved.

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Document Details

Document Type
Technical Report
Publication Date
Jun 30, 2010
Accession Number
ADA526004

Entities

People

  • B. Birang
  • Chris L. Lin
  • J Klein
  • N. Bykovetz

Organizations

  • United States Army Communications-Electronics Command

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Continuous Waves
  • Crystal Structure
  • Data Sets
  • Domain Walls
  • Electric Fields
  • Frequency
  • Information Operations
  • Low Temperature
  • Measurement
  • Resistance Thermometers
  • Resonance
  • Spin Waves
  • Splitting
  • Three Dimensional
  • Two Dimensional
  • Universities

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.
  • Superconducting Magnet Technology

Technology Areas

  • Space