2017/02/13 by Pavol Hrubovčák, Hrubovcak, P., A. Zeleňáková +7
Materials Science · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #FOS: Physical sciences #Material Dynamics and Properties #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Theoretical and Computational Physics
paper · pdf · doi:10.48550/arxiv.1702.03761
openalex publication_date 2017/02/13 · openalex created_date 2017/04/28 · openalex updated_date 2026/07/28
Bimetallic Co/Au (core/shell) nanoparticle system exhibiting transition form superparamagnetic (SPM) to superspin glass state (SSG) at low temperatures has been investigated with respect to its magnetocaloric properties. Peaks of magnetic entropy change vs. temperature dependences (ΔSM(T)) have been observed at a temperature in the vicinity of SPM to SSG transition. Despite of significant thermal hysteresis of magnetization at low applied fields a master curve has been constructed from the ΔSM(T) dependences employing scaling analysis. That confirms the investigated transition is of the second order type. Different values of critical exponents calculated from field dependence of relevant magnetocaloric response parameters in the proximity of critical temperature have been found for low and high applied fields. Moreover, the exponents exhibited significant disagreement with theoretical values characteristic of mean field theory as well as Ising models indicating distinct behavior of the SSG system at critical temperature.