Chromium oxyselenide solid solutions from the atmospheric pressure chemical vapour deposition of chromyl chloride and diethylselenide

Abstract

A new chromium oxyselenide solid–solution series Cr₂O_3−xSe_x (x = 0, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.7, 1.5, 2.15) was formed by the atmospheric pressure chemical vapour deposition of chromyl chloride and diethylselenide at 600 °C. The level of selenium incorporation was directly related to the gas-phase molar flows of reagents. There was a crossover in structure type adopted by the chromium oxyselenide with selenium incorporation, at x = 0–0.2 the solid solution crystallises in the Cr₂O₃ structure type, at x = 0.3–2.15 it adopts the Cr₂Se₃ structure type. All of the chromium oxyselenides were antiferromagnets. They showed a variation in Néel temperature with composition with a minimum temperature of 11 K observed for x = 0.7.