Nitride tuning of lanthanide chromites.

LnCrO3−xNx perovskites with Ln = La, Pr and Nd and nitrogen contents up to x = 0.59 have been synthesised through ammonolysis of LnCrO4 precursors. These new materials represent one of the few examples of chromium oxynitrides. Hole-doping through O2−/N3− anion substitution suppresses the magnetic transition far less drastically than Ln3+/M2+ (M = Ca, Sr) cation substitutions because of the greater covalency of metal–nitride bonds. Hence, nitride-doping is a more benign method for doping metal oxides without suppressing electronic transitions. [ABSTRACT FROM AUTHOR]