The lower symmetry electron-density distribution and the charge transport anisotropy in cubic dodecaboride LuB12

TL;DR

This study reveals that the electron-density distribution in LuB12 is lower than cubic symmetry, explaining the anisotropic charge transport despite apparent cubic structure, through advanced X-ray analysis and a novel computational approach.

Contribution

The paper introduces a new computational strategy to resolve the contradiction between observed cubic symmetry and lower true symmetry of electron density in LuB12.

Findings

Electron-density distribution in LuB12 is lower than cubic symmetry.

Charge transport in LuB12 is highly anisotropic.

A new method accurately correlates electron density symmetry with transport properties.

Abstract

High-quality single crystals of LuB12 are grown using the induction zone melting method. The X-ray data are collected at temperatures 293, 135, 95, 50 K. The crystal structure of LuB12 can be refined with record low R-factor in the cubic Fm-3m symmetry group despite reiterated observations of the cubic symmetry distortions both in the unit-cell values and in the physical properties. A peculiar computing strategy is developed to resolve this contradiction. True symmetry of the electron-density distribution in LuB12 is proved to be much lower than cubic as a result, which correlates very accurately with anisotropy of transport properties of LuB12.