Layer-by-layer deposition of epitaxial TiN–CrN multilayers on MgO(0 0 1) by pulsed laser ablation

Titanium nitride (TiN)–chromium nitride (CrN) multilayers were deposited epitaxially on MgO(0 0 1) by pulsed laser ablation combined with nitrogen radical irradiation. High quality TiN film was first deposited on MgO(0 0 1) substrate. During the alternate deposition of six TiN monolayers and three CrN monolayers, reflection high-energy electron diffraction (RHEED) intensity oscillations were observed continuously, showing layer-by-layer growth of a transition metal nitride multilayer structure. An X-ray diffraction peak corresponding to a multilayer periodicity of 2.1 nm was observed. The multilayer sample showed metallic conductivity and ferromagnetic behavior with a Curie temperature of ca. 70 K. The ferromagnetism may be attributable to the formation of a TiN–CrN mixed phase at the multilayer boundaries