By heating mixtures of H3BO3, TiCl4, and NbCl5 With urea in 1:6 molar ratios in the 900-1000 degrees C range, nanoparticles of BN, TiN. and NbN have been obtained, respectively. The nanoparticles are crystalline and have been characterized by electron microscopy and other techniques. By carrying out the urea reaction over An islands deposited on Si substrates, nanowires of TiN could be obtained. (C) 2006 Elsevier Ltd. All rights reserved.