A novel nitride solid solution, NixTi1-xNy (0 less than or equal to x less than or equal to 0.31, 0.59 less than or equal to y less than or equal to 1) was grown on MgO(0 0 1) using a pulsed laser deposition (PLD) method combined with R F nitrogen radical irradiation. Compressed disks made of mixtures of titanium hydride and nickel metal were used as the PLD targets. Simple Ti-Ni alloyed targets gave no crystalline nitride. High-resolution X-ray diffraction reciprocal space mapping revealed that the deposited films were epitaxially grown on MgO(0 0 1) and that the lattice of the films shrunk to fit the lattice of MgO(0 0 1) in the plane. The lattice constant perpendicular to the plane decreased linearly as the Ni content increased up to x = 0.31, demonstrating the incorporation of Ni atoms into the crystal structure. These thin films were metallic conductors. X-ray photoelectron spectra showed that the substitution of Ti for Ni brought about the formation of large amounts of nitrogen vacancies. (C) 2002 Elsevier Science B.V. All rights reserved.