Synthesis and transport properties of SrTiO3−xNy/SrTiO3−δ layered structures produced by microwave-induced plasma nitridation

SrTiO3-xNy/SrTiO3-delta layered structures were synthesized from single crystals of SrTiO3 (1 0 0) by ammonolysis using a microwave-induced plasma (MIP). Samples prepared using a low ammonia flow rate (50-100 mL min-1) gave nanocrystals of TiN at the surface, while the samples prepared in an ammonia flow in the range 125-175 mL min-1 did not show impurity phases. Electrical resistance measurements of SrTiO3-xNy/SrTiO3-delta single crystals show metallic-like behaviour in the temperature range 2-300 K, with a residual resistance ratio R(300 K)/R(4.2 K) of ca 50. The Hall mobility follows the power law muH {proportional to} T-2.3 in the temperature range 150-300 K, which is attributed to n-type charge carriers.