2002/07/17 by O. Petracic, S. Sahoo, Siva Satyendra Sahoo +13
Engineering · Physics and Astronomy · #Disordered Systems and Neural Networks (cond-mat.dis-nn) #FOS: Physical sciences #Magnetic properties of thin films #Metallic Glasses and Amorphous Alloys #Statistical Mechanics (cond-mat.stat-mech) #Theoretical and Computational Physics #cond-mat.dis-nn #cond-mat.stat-mech
paper · pdf · doi:10.48550/arxiv.cond-mat/0207417
11 pages (LaTeX2e), 6 figures (eps), Proceedings SDHS 2001-Duisburg, Germany, submitted to Phase Transitions
arxiv created 2002/07/17 · openalex publication_date 2002/07/17 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Ac susceptibility measurements were performed on discontinuous magnetic multilayers [Co80Fe20(t)/Al2O3(3nm)]x10, t = 0.9 and 1.0nm, by Superconducting Quantum Interference Device (SQUID) magnetometry. The CoFe forms nearly spherical ferromagnetic single-domain nanoparticles in the diamagnetic Al2O3 matrix. Due to dipolar interactions and random distribution of anisotropy axes the system exhibits a spin-glass phase. We measured the ac susceptibility as a function of temperature 20 < T < 100K at different dc fields and as a function of frequency 0.01 < f < 1000Hz. The spectral data were successfully analysed by use of the phenomenological Cole-Cole model, giving a power-law temperature dependence of the characteristic relaxation time tauc and a high value for the polydispersivity exponent, alpha = 0.8, typical of spin glass systems.