Magnetic behavior of metallic kagome lattices, Tb3Ru4Al12 and Er3Ru4Al12

TL;DR

This study investigates the magnetic properties of kagome lattice intermetallics Tb3Ru4Al12 and Er3Ru4Al12, revealing complex glassy behavior and magnetic phase phenomena, with implications for understanding magnetic frustration and higher-order interactions.

Contribution

It is the first detailed exploration of magnetic frustration and glassy phases in these specific kagome lattice intermetallics, highlighting the role of higher-order interactions.

Findings

Tb3Ru4Al12 exhibits re-entrant spin-glass behavior below 15 K.

Hysteresis in susceptibility and resistivity indicates a magnetic phase transition.

Magnetoresistance shows phase coexistence phenomena after cycling across metamagnetic transitions.

Abstract

We report magnetic behavior of two intermetallics-based kagome lattices, Tb3Ru4Al12 and Er3Ru4Al12, crystallizing in the Gd3Ru4Al12-type hexagonal crystal structure, by measurements in the range 1.8-300 K with bulk experimental techniques (ac and dc magnetization, heat-capacity and magnetoresistance). The main finding is that the Tb compound, known to order antiferromagnetically below (T_N=) 22 K, shows glassy characteristics at lower temperatures (<15K), thus characterizing this compound as a re-entrant spin-glass. The data reveal that glassy phase is quite complex and is of a cluster type. Since the glassy behavior was not seen for the Gd analogue in the past literature, this finding for the Tb compound emphasizes that this kagome family could provide an opportunity to explore the role of higher order (such as quadrupole) in bringing out magnetic frustration. Additional findings reported here for this compound are: (i) The temperature dependence of magnetic susceptibility and electrical resistivity in the range 12 - 20 K are found to be hysteretic leading to a magnetic phase in this temperature range, mimicking disorder-induced first-order magnetic phase-transition. (ii) Features attributable to an interesting magnetic phase co-existence phenomenon in the magnetoresistance in zero field, after cycling across metamagnetic transition fields, are observed. With respect to the Er compound, we do not find any evidence for long-range magnetic ordering down to 2 K, but this appears to be on the verge of magnetic order at 2 K.