Magnetotransport properties of BaRuO$_3$: Observation of two scattering rates

TL;DR

This study investigates the magnetotransport properties of two BaRuO$_3$ polymorphs, revealing distinct electronic behaviors and the presence of two scattering rates in the rhombohedral form, advancing understanding of structure-property relationships.

Contribution

It provides the first detailed comparison of magnetotransport in 4H and 9R BaRuO$_3$, highlighting the existence of two scattering rates and differing magnetic responses.

Findings

4H BaRuO$_3$ exhibits Fermi-liquid behavior down to 1.8 K.

9R BaRuO$_3$ shows a resistivity crossover around 150 K and two scattering rates.

Magnetoresistance is negative in 9R and positive in 4H BaRuO$_3$.

Abstract

We report results of low-temperature magnetotransport and Hall measurements on single crystals of four-layered hexagonal (4H) and nine-layered rhombohedral (9R) BaRuO$_3$ that provide insight into the structure-property relationships of BaRuO$_3$ polymorphs. We found that 4H BaRuO$_3$ possesses Fermi-liquid behavior down to the lowest temperature ($T$) of our measurements, 1.8 K. On the other hand, 9R BaRuO$_3$ was found to show a crossover in the temperature dependence of resistivity around 150 K, and the existence of two separate scattering rates at low temperatures. The magnetoresistance in the 9R BaRuO$_3$ was found to be negative while that in the 4H BaRuO$_3$ is positive. We propose that local moments may be present in 9R but not in 4H BaRuO$_3$, which leads to distinctly different behavior in the two forms.