2008/10/15 by Stephen Eckel, S. Eckel, Alexander O. Sushkov +2 · 2 citations
Engineering · Physics and Astronomy · #Atomic and Subatomic Physics Research #Characterization and Applications of Magnetic Nanoparticles #Magneto-Optical Properties and Applications #cond-mat.mtrl-sci #cond-mat.other
paper · pdf · doi:10.1103/physrevb.79.014422
arxiv created 2008/10/15 · openalex publication_date 2009/01/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the magnetic properties of gadolinium-yttrium iron garnet (GdxY_3\ensuremath-xFe5O12,x=3,1.8) ferrite ceramics. The complex initial permeability is measured in the temperature range of 2--295 K at frequency of 1 kHz and in the frequency range of 100 Hz--200 MHz at temperatures of 4, 77, and 295 K. The magnetic viscosity-induced imaginary part of the permeability is observed at low frequencies. Measurements of the magnetization noise are made at 4 K. Using the fluctuation-dissipation theorem, we find that the observed magnetization fluctuations are consistent with our measurements of the low-frequency imaginary part of the permeability. We discuss some implications for proposed precision measurements as well as other possible applications.