Reentrant cluster glass behavior in La2CoMnO6 nanoparticles

TL;DR

This study investigates La2CoMnO6 nanoparticles, revealing multiple magnetic transitions, mixed valence states, and a reentrant cluster glass behavior caused by competing interactions and disorder.

Contribution

It uncovers reentrant cluster glass behavior in La2CoMnO6 nanoparticles driven by mixed valence states and antisite disorder, which was not previously reported.

Findings

Multiple magnetic transitions at 218 K, 135 K, and below 38 K.

Presence of non-interacting magnetic clusters below 38 K.

Reentrant cluster glass state due to competing interactions.

Abstract

Magnetic study on La2CoMnO6 nanoparticles revealed multiple magnetic transitions at 218 K, 135 K and below 38 K and the nature of the low temperature transition was unclear [J Appl Phys 111, 024102 2012]. Presence of mixed valance states of Co and Mn has been confirmed from the XPS measurement and its presence along with antisite disorder affects in reducing the saturation magnetization of the nanoparticles. The zero field cooled and field cooled bifurcation in dc magnetization, relaxation in zero field cooled magnetization and large enhancement in coercive field below the glassy temperature has been discussed. Frequency dependence of ac susceptibility using power law has revealed cluster glass behavior. Further, the dc field superimposed on ac susceptibility and absence of memory effect in ac susceptibility has suggested the existence of non interacting clusters comprising of competing interactions below 38 K. Competing magnetic interactions due to the presence of mixed valances and antisite disorder found to establish a reentered cluster glassy state in the nanoparticles.