Charge-ordered state satisfying the Anderson condition in LiRh2O4 arising from local dimer order

TL;DR

This study uncovers a charge-ordered state in LiRh2O4 below 170 K, characterized by Rh3+ and Rh4+ dimerization, with Coulomb interactions influencing the charge ordering pattern, similar to but distinct from related compounds.

Contribution

It reveals a charge-ordered state satisfying the Anderson condition in LiRh2O4, highlighting the role of Coulomb interactions and structural dimerization in its low-temperature phase.

Findings

Charge ordering occurs below 170 K with Rh3+ and Rh4+ dimers.

The charge order pattern satisfies the Anderson condition.

Coulomb interactions influence the charge ordering pattern.

Abstract

We report on the charge-ordered structure of LiRh2O4 arising below the metal-insulator transition at 170 K. Structural studies using synchrotron X-rays have revealed that the charge-ordered states of Rh3+ and Rh4+ with dimerization are realized in the low-temperature phase below 170 K. Although the low-temperature ground state resembles that of CuIr2S4, a charge ordering pattern satisfying the Anderson condition is realized in LiRh2O4. Based on structural information such as the short-range order of dimers appearing above the transition temperature and the weakening of the correlation between rhodium one-dimensional chains appearing in the crystal structure, we argue that the Coulomb interaction plays an important role in determining the charge ordering patterns.