Observation of different spin behavior with temperature variation and Cr substitution in a multiferroic compound YMn$_2$O$_5$

TL;DR

This study investigates how temperature variation and Cr substitution affect spin behavior in the multiferroic compound YMn$_2$O$_5$, revealing significant changes in magnetic ordering and memory effects.

Contribution

It demonstrates that Cr substitution induces a transition from antiferromagnetic to ferrimagnetic order and introduces magnetic memory effects without altering the atomic structure.

Findings

Cr substitution enhances magnetic ordering temperature.

Cr-doped compound exhibits ferrimagnetic order.

Magnetic memory effect observed in Cr-substituted sample.

Abstract

In this article, the collective response of the spins is explored through low field bulk magnetic measurement for the series YMn$_{2-x}$Cr$_x$O$_5$ (x= 0.0, 0.05). Low field ac susceptibility and dc magnetization of YMn$_2$O$_5$ shows multiple transition in analogy to those observed in electrical measurement of the compound. Using various time dependent magnetization protocols it has been observed that the behavior of spins in commensurate and incommensurate phase are drastically different. YMn$_{1.95}$Cr$_{0.05}$O$_5$ undergoes a ferrimagnetic ordering with an enhanced magnetic ordering temperature as compared to the parent, which undergoes an antiferromagnetic ordering. Appearance of spontaneous magnetization without any major change in the atomic structure is rather significant since the parent compound is an important multiferroic material. In addition, magnetic memory effect is observed in the Cr substituted compound whereas it is absent in the parent compound.