Anionic depolymerization transition in IrTe2

TL;DR

This study investigates how selenium substitution affects the depolymerization transition in IrTe2, revealing a significant increase in transition temperature and structural modulation changes, highlighting a unique depolymerization process in inorganic crystals.

Contribution

It demonstrates that Se substitution raises the transition temperature and alters structure modulations in IrTe2, providing new insights into depolymerization transitions in inorganic solids.

Findings

Se substitution increases transition temperature from 278 K to 560 K

Structural modulations evolve from q=1/5 to q=1/6 types

Depolymerization transition is destabilized by Se substitution and pressure

Abstract

Selenium (Se) substitution drastically increases the transition temperature of iridium ditelluride (IrTe$_{2}$) to a diamagnetic superstructure from 278 K to 560 K. Transmission electron microscopy experiments revealed that this enhancement is accompanied by the evolution of non-sinusoidal structure modulations from $q = 1/5(10\bar{1})$- to $q = 1/6(10\bar{1})$-types. These comprehensive results are consistent with the concept of the destabilization of polymeric Te-Te bonds at the transition, the temperature of which is increased by chemical and hydrostatic pressure and by the substitution of Te with the more electronegative Se. This temperature-induced depolymerization transition in IrTe$_{2}$ is unique in crystalline inorganic solids.