Magnetocaloric effect and scaling analysis in superspinglass cobalt based nanoparticles

The magnetocaloric effect has been investigated in bimetallic Co/Au (core/shell) nanoparticles system exhibiting magnetic transition and non-equilibrium spin dynamics at low temperatures. The analysis of system's magnetocaloric properties by means of Maxwell relations application to both isothe...

Full description

Saved in:
Bibliographic Details
Published in:Journal of alloys and compounds 2019-10, Vol.805, p.767-773
Main Authors: Zeleňáková, Adriana, Hrubovčák, Pavol, Zeleňák, Vladimir, Kováč, Jozef, Franco, Victorino
Format: Article
Language:English
Subjects:
Bimetals
Cobalt
Critical temperature
Cryogenic applications
Dependence
Gold
Magnetic nanoparticles
Magnetic properties
Magnetic transition
Magnetic transitions
Magnetization
Magnetocaloric effect
Nanoparticles
Refrigeration
Scaling analysis
Spin dynamics
Temperature
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The magnetocaloric effect has been investigated in bimetallic Co/Au (core/shell) nanoparticles system exhibiting magnetic transition and non-equilibrium spin dynamics at low temperatures. The analysis of system's magnetocaloric properties by means of Maxwell relations application to both isothermal and zero field cooling magnetization data has been performed. Peaks of magnetic entropy change vs. temperature dependences (ΔSM(T)) have been observed at a temperature in the vicinity of the magnetic 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. Along with the unique feature of Co/Au (core/shell) nanoparticle systems, where the working temperature of the potential refrigerant can be tuned easily by particles size change, this kind of system appears promising candidate for the future cryogenic magnetic refrigeration applications. •Magnetocaloric effect in Co/Au nanoparticles with non-equilibrium spin dynamics.•Application of scaling analysis of ΔSM(T) developed for bulk materials on nanoparticle systems.•Combination of unique nanostructure, low cost, easily preparation and magnetocaloric responses.•MCE characteristics suitable for devices for nano-energy applications.
ISSN:0925-8388
1873-4669
DOI:10.1016/j.jallcom.2019.07.132