ABSTRACTReduction of aqueous solutions of tungstates, molybdates or vanadates by
aqueous alkali metal borohydrides at ambient‐temperature results in a
formation of dark colored gel. The gel is amorphous to X‐ray diffraction and
crystallizes sharply at around 300‐500 °C to yield reduced transition metal
oxides such as the oxide bronzes, NaxMyOz,
or the binary oxides, MO2 (M = V, Mo or W). The nature and
composition of the products formed are strongly influenced by the reaction
conditions such as the reaction pH as well as the concentration and amount
of the reagents. Experimental procedures to obtain the different phases are
presented. This novel low‐temperature approach has a potential to access new
metastable phases.
Which orbital and charge ordering in transition metal oxides can resonant X-ray diffraction detect?