In this review we describe recent advances in transition metal oxyhydride chemistry obtained by topochemical routes, such as low temperature reduction with metal hydrides, or high-pressure solid-state reactions. Besides the crystal chemistry, magnetic and transport properties of the bulk powder and epitaxial thin film samples, the remarkable lability of the hydride anion is particularly highlighted as a new strategy to discover unprecedented mixed anion materials.
Keywords: 107 Glass and ceramic materials; 201 Electronics / Semiconductor / TCOs; 203 Magnetics / Spintronics / Superconductors; 60 New topics / Others; Oxyhydride; hydride; mixed anions; solid-state chemistry.