Neutron diffraction study of a metallic kagome lattice, Tb3Ru4Al12

TL;DR

This neutron diffraction study of Tb3Ru4Al12 reveals incommensurate long-range antiferromagnetic order with unusual behavior across the spin-glass transition, suggesting exotic magnetism possibly due to geometrical frustration.

Contribution

First neutron diffraction analysis of Tb3Ru4Al12 showing incommensurate antiferromagnetic order and its temperature-dependent behavior, highlighting its exotic magnetic properties.

Findings

Long-range incommensurate antiferromagnetic order below 22 K.

No decrease in magnetic Bragg peak intensity below 17 K.

Potential evidence for dynamical spin-glass freezing due to geometrical frustration.

Abstract

We present the results of neutron diffraction studies on polycrystals of a metallic kagome lattice, Tb3Ru4Al12, reported recently to undergo reentrant magnetism, with the onset of long range antiferromagnetic order below (TN=) 22 K and spin-glass features below about 17 K. The present results reveal long-range antiferromagnetic order of an incommensurate type with the moments oriented along c-axis at all temperatures below TN. There are however notable changes in the T dependence of propagation vector along b-axis across 17 K. An observation of interest is that there is no decrease of intensity of magnetic Bragg peaks on entrance into the glassy phase (that is, below 17 K). This finding suggests that the magnetism of this compound is an exotic one and we wonder whether this compound is an example for dynamical spin-glass freezing phenomenon, as a consequence of geometrical frustration.