The low-temperature nitridation of gallium arsenide, silicon and transition metals was investigated using hydrazine. Gallium nitride films were grown on gallium arsenide (GaAs) by direct reaction of the semiconductor surface layers with hydrazine at 200 - 400 degrees C. Auger electron spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses show that the films are primarily gallium nitride with a small oxide impurity Thin nitride films (similar to 15 Angstrom) were grown on silicon by reaction with hydrazine at 300-500 degrees C. Ellipsometry results suggest that the film growth goes through different phases following linear, parabolic and logarithmic functions with time. XPS analysis shows that the nitride films could be formed at much lower temperatures than possible with ammonia (300 vs.,600 degrees C). The formation of numerous transition metal nitrides (Go, Cr, Fe, Mo, Si, Ta, Ti, V, and W) by reaction with hydrazine at 400 degrees C is demonstrated, as well as the chemical vapor deposition of boron nitride films from diborane and hydrazine reactants. The temperature at the mixing point was critical in determining the final composition of the film. A 1-D transport model suggests that the reaction rate at 400 degrees C was kinetically limited The results also agree qualitatively with thermodynamic equilibrium calculations.