Stuffed Rare Earth Garnets

TL;DR

This study synthesizes and characterizes stuffed rare earth gallium garnets with excess rare earth ions, revealing altered magnetic properties and partial site occupancy, contributing to understanding of magnetic frustration and disorder in garnets.

Contribution

It introduces a new synthesis method for stuffed rare earth garnets with controlled excess ions and investigates their magnetic behavior and entropy.

Findings

Reduced Curie-Weiss constants and effective moments.

No significant change in field-dependent magnetization.

Missing entropy at low temperatures.

Abstract

We report the synthesis and magnetic characterization of stuffed rare earth gallium garnets, RE3+xGa5-xO12 (RE=Lu, Yb, Er, Dy, Gd), for x up to 0.5. The excess rare earth ions partly fill the octahedral sites normally fully occupied by Ga3+, forming disordered pairs of corner-shared face-sharing magnetic tetrahedra. The Curie-Weiss constants and observed effective moments per rare earth are smaller than are seen for the unstuffed gallium garnets. No significant change in the field-dependent magnetization is observed but missing entropy is seen when integrating the low-temperature heat capacity to 0.5 K.