In the layered copper chromium dichalcogenide series CuCrX2, the oxide, the sulfide, and the selenide analogues have been reported, but the telluride CuCrTe2 has remained unsynthesized so far. Here, we report the synthesis of Cu1−xCrTe2 (x≈0.3), which forms only within a narrow temperature window near 90 {\deg}C by solvothermal cation exchange of K1−xCrTe2 (x≈0.3) and CuBr. Cu1−xCrTe2 undergoes a magnetostructural transition to an antiferromagnetic state at TN=239 K, a N\'eel temperature that is high relative to other ACrTe2 phases and comparable to that of ferromagnetic, fully-deintercalated CrTe2. Cu1−xCrTe2 is metastable and decomposes at temperatures as low as 250 {\deg}C to form spinel CuCr2Te4. These results highlight the importance of low-temperature topochemical routes for accessing metastable Cu(I)-containing tellurides that are inaccessible by conventional solid-state synthesis.
@article{arxiv.2605.18400,
title = {Metastable Cu$_{1-x}$CrTe$_2$ -- Completing the copper chromium delafossite series through soft chemistry},
author = {Kai D. Röseler and Geo Sciarini and Felix Eder and Samuel Moody and Vladimir Pomjakushin and Fabian O. von Rohr},
journal= {arXiv preprint arXiv:2605.18400},
year = {2026}
}