Nitride tuning of lanthanide chromites

Abstract

LnCrO_3−xN_x 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.