Magnetic behavior of nanocrystalline ErCo2

TL;DR

This study explores how nanocrystalline ErCo2 exhibits altered magnetic properties, including ferromagnetic Co at room temperature and reduced magnetic moments, compared to its bulk form, with implications for magnetocaloric applications.

Contribution

It provides new insights into the magnetic behavior of nanocrystalline ErCo2, highlighting changes in magnetic ordering and moments due to nanostructuring, which were not previously characterized.

Findings

Co shows ferromagnetic order at room temperature in nanocrystals

The Er sublattice transition temperature remains unchanged

The high-field magnetic moment is significantly reduced

Abstract

We have investigated the magnetic behavior of the nanocrystalline form of a well-known Laves phase compound, ErCo2 - the bulk form of which has been known to undergo an interesting first-order ferrimagnetic ordering near 32 K - synthesized by high-energy ball-milling. It is found that, in these nanocrystallites, Co exhibits ferromagnetic order at room temperature as inferred from the magnetization data. However, the magnetic transition temperature for Er sublattice remains essentially unaffected as though the (Er)4f-Co(3d) coupling is weak on Er magnetism. The net magnetic moment as measured at high fields, sat at 120 kOe, is significantly reduced with respect to that for the bulk in the ferrimagnetically ordered state and possible reasons are outlined. We have also compared the magnetocaloric behavior for the bulk and the nano particles.