A dynamic probe of finite-size effects near the spin-glass transition temperature

ORAL

Abstract


Using a high sensitivity dual DC SQUID magnetometer, we have measured the growth of the spin glass correlation length, through the aging and end of aging effects. Measurements were made on bulk CuMn5% and a CuMn12% thin film multilayer with CuMn layer thicknesses of 4.5 nm. As the glass temperature Tg is approached (0.9Tg < T<0.96Tg) in the bulk sample, we find that the waiting time effect (as measured by the time associated with the inflection point of the decay) as a function of increasing temperature, shifts to shorter timescales. For T >0.96Tg, there is no waiting time effect (end of aging) on the magnetization decay. and all decays collapse onto a single decay curve indicating an end of aging even for long waiting times (tw = 10,000s). For the thin film, all effects due to the waiting time disappear at around 0.89Tf, where Tf is the freezing temperature marking the onset of irreversibility. The end of aging results are interpreted in terms of the spin glass correlation length saturating due to finite size effects.

–

Presenters

  • Gregory Kenning

    Physics, Indiana University of Pennsylvania

Authors

  • Gregory Kenning

    Physics, Indiana University of Pennsylvania

  • Daniel Tennant

    Physics, University of Texas, Institute for Quantum Computing, Department of Physics and Astronomy, and Waterloo Institute for Nanotechnology, University of Waterloo

  • Qiang Zhai

    The University of Texas at Austin, Physics, University of Texas

  • David Harrison

    University of Minnesota Twin Cities, Physics, University of Minnesota, University of Minnesota - Twin Cities

  • E. Dan Dalhberg

    Physics, University of Minnesota, University of Minnesota - Twin Cities

  • Raymond Orbach

    The University of Texas at Austin, Physics, University of Texas, University of Texas at Austin