Heavy Prussian Blue Analog with Magnetic Ordering above 400 K

Abstract Molecule‐based magnets hold promise for a variety of applications in information technologies owing to their chemical tunability. This feature can facilitate the integration of desired magnetic properties alongside additional functionalities within a single material. Although numerous cyanido‐bridged assemblies are identified as multifunctional materials at cryogenic temperatures, achieving analogous behavior at room temperature remains a challenge. This study reports a cyanido‐bridged compound, which shows ferrimagnetic ordering with a critical temperature exceeding 400 K. This breakthrough is achieved through the mechanochemical synthesis of vanadium(II)‐hexacyanomolybdate(III) Prussian Blue Analog (PBA) under anhydrous conditions. The ferrimagnetic order is evidenced by SQUID (SQUID = superconducting quantum interference device) magnetometry and X‐ray Magnetic Circular Dichroism (XMCD) spectroscopy. Both techniques unambiguously confirm the antiparallel alignment of vanadium and molybdenum magnetic moments. As a result, hexacyanomolybdate(III) is experimentally established as a viable precursor for the preparation of a new generation of high‐temperature molecule‐based magnets and multifunctional materials.