Competition between Ferrimagnetism and Magnetic Frustration in Zinc Substituted YBaFe4O7

TL;DR

This study investigates how zinc substitution in YBaFe4O7 influences its magnetic properties, revealing a competition between ferrimagnetism and magnetic frustration, with structural and magnetic behaviors evolving with zinc content.

Contribution

It demonstrates that zinc substitution induces ferrimagnetism and magnetic frustration, providing insight into the interplay between structural changes and magnetic states in this oxide series.

Findings

Zinc substitution changes crystal symmetry from cubic to hexagonal.

Zinc induces ferrimagnetism contrasting the original spin glass behavior.

Magnetic frustration increases with higher zinc content, leading to glassy states.

Abstract

The substitution of zinc for iron in YBaFe4O7 has allowed the oxide series YBaFe4-xZnxO7, with 0.40 < x < 1.50, belonging to the "114" structural family to be synthesized. These oxides crystallize in the hexagonal symmetry (P63mc), as opposed to the cubic symmetry (F-43m) of YBaFe4O7. Importantly, the d.c. magnetization shows that the zinc substitution induces ferrimagnetism, in contrast to the spin glass behaviour of YBaFe4O7. Moreover, a.c. susceptibility measurements demonstrate that concomitantly these oxides exhibit a spin glass or a cluster glass behaviour, which increases at the expense of ferrimagnetism, as the zinc content is increased. This competition between ferrimagnetism and magnetic frustration is interpreted in terms of lifting of the geometric frustration, inducing the magnetic ordering, and of cationic disordering, which favours the glassy state.