Ba2CrIO3F6: a magnetic alkaline-earth chromium fluoroiodate with ferromagnetic exchange interactions

A novel magnetic alkaline-earth chromium fluoroiodate Ba 2 CrIO 3 F 6 has been successfully synthesized via the hydrothermal method and characterized for its structure and physical properties by single crystal X-ray diffraction, attenuated total reflection (ATR) infrared spectroscopy, UV-vis-NIR spectroscopy, thermal stability, as well as magnetic susceptibility, and specific heat. The compound Ba 2 CrIO 3 F 6 contains the [CrIO 3 F 6 ] 4- spin chains which are further separated by nonmagnetic Ba 2+ cations. The magnetic susceptibility results show no long-range magnetic order down to 2 K, which are further confirmed by specific heat measurement. The positive Weiss temperature and the increase of χT - T curve at low temperature both suggest the magnetic exchange interactions through the Cr 3+ −IO 4 F−Cr 3+ pathway are unexpectedly ferromagnetic. Our work illustrates that it is promising to use the IO x F y anion group for the design and construction of novel magnetic materials with ferromagnetic exchange interactions for potential spintronics device applications.