# Magnetization process and magnetocaloric effect in geometrically frustrated Ising antiferromagnet and spin ice models on a `Star of David' nanocluster

## TL;DR

This study investigates the magnetization and magnetocaloric effects in frustrated Ising antiferromagnet and spin ice models on a 'Star of David' nanocluster, revealing multiple magnetization plateaus and a giant magnetocaloric effect under certain conditions.

## Contribution

It provides the first exact enumeration analysis of these models on a 'Star of David' nanocluster, highlighting novel magnetization plateaus and magnetocaloric phenomena influenced by NNN interactions.

## Key findings

- Multiple intermediate magnetization plateaus in IA model.
- Giant magnetocaloric effect observed with specific NNN interactions.
- Abrupt entropy changes and rapid temperature variations at critical fields.

## Abstract

Magnetic and magnetocaloric properties of geometrically frustrated antiferromagnetic Ising (IA) and ferromagnetic spin ice (SI) models on a nanocluster with a `Star of David' topology, including next-nearest-neighbor (NNN) interactions, are studied by an exact enumeration. In an external field applied in characteristic directions of the respective models, depending on the NNN interaction sign and magnitude, the ground state magnetization of the IA model is found to display up to three intermediate plateaus at fractional values of the saturation magnetization, while the SI model shows only one zero-magnetization plateau and only for the antiferromagnetic NNN coupling. A giant magnetocaloric effect is revealed in the the IA model with the NNN interaction either absent or equal to the nearest-neighbor coupling. The latter is characterized by abrupt isothermal entropy changes at low temperatures and infinitely fast adiabatic temperature variations for specific entropy values in the processes when the magnetic field either vanishes or tends to the critical values related to the magnetization jumps.