Nonaqueous synthesis of low-vacancy chromium hexacyanochromate
Prussian Blue Analogues (PBA) are a highly tunable family of materials with properties suitable for a wide variety of applications. Although their straightforward aqueous synthesis allows for the facile preparation of a diverse set of composition, the use of water as the solvent has hindered the preparation of specific compositions with highly sought-after properties.
A typical example is CR[CR(CN)6]; its predicted strong magnetic interactions have motivated many attempts at its synthesis but with limited success. The lack of control over vacancies, crystallinity and the oxidation state has prevented the experimental validation of its theoretical magnetic properties.
In the paper 'Nonaqueous Synthesis of Low-Vacancy Chromium Hexacyanochromate', the authors* report the nonaqueous synthesis of vacancy-suppressed nanocrystalline chromium hexacyanochromate. The control over vacancies and the oxidation state led to stronger magnetic interactions with a markedly increased absolute Weiss temperature (Θ = -836(6) K) and magnetic ordering temperature of (240± 10) K. Their results challenge the notion of the solvent as merely a reaction medium. They also introduce a pathway for exploring moisture and air-sensitive PBA compositions.
*The authors were led by Oxford Materials and were comprised of members of Oxford Materials, ISIS Pulsed Neutron and Muon Source (STFC), University of Rennes and the Inorganic Chemistry Laboratory (Oxford).
