Enhancement of the magnetocaloric effect in geometrically frustrated cluster spin glass systems

Abstract

In this work, we theoretically demonstrate that a strong enhancement of the Magnetocaloric Effect is achieved in geometrically frustrated cluster spin-glass systems just above the freezing temperature. We consider a network of clusters interacting randomly which have
triangular structure composed of Ising spins interacting antiferromagnetically. 
The intercluster disorder problem is treated using a cluster spin glass mean-field theory, which allows exact solution of the disordered problem. The intracluster part can be solved using exact enumeration. 
The coupling between the inter and intracluster problem incorporates the interplay between effects coming from geometric frustration and disorder. As a result, it is shown that there is the onset of cluster spin glass phase even with very weak disorder.
Remarkably, it is exactly within a range of very weak disorder and small magnetic field that is observed the strongest isothermal release of entropy. 

Enhanced cryogenic magnetocaloric performance and the existence of short-range magnetic correlations in frustrated diamond geometries

“…This frustration can suppress long-range ordering (LRO) down to 0 K and give rise to nontrivial magnetic behaviour. Along with this, various theoretical investigations indicate that a large MCE can be obtained in frustrated geometries such as Kagome, hyper-Kagome and pyrochlore lattices [8,9]. This has also been confirmed experimentally in various systems, including Gd-based pyrochlores [10][11][12][13].…”

Interplay of Competing Magnetic Interactions in Noncentrosymmetric Nd3Te4 for Enhancing the Magnetocaloric Properties

“…Furthermore, the competing symmetric and antisymmetric magnetic interactions lead to enhanced entropic changes over a wide temperature range and ultimately contribute to the magnetocaloric properties. Several frustrated systems have reported an enhancement in the magnetocaloric effect (MCE). ,− The magnetocaloric effect is the cooling response of a material as an effect of an increase in the applied magnetic field under adiabatic conditions. Within the field of magnetic refrigeration, rare-earth-based materials have garnered significant attention due to the presence of unpaired 4f electrons responsible for the origin of complex magnetism .…”