Abstract
Transition Metal (TM) ions V, Cr, Mn and Co were implanted into GaN/sapphire films at fluences 5 x 10(14), 5 x 10(15) and 5 x 10(16) cm(-2). First order Raman Scattering (RS) measurements were carried out to study the effects of ion implantation on the microstructure of the materials, which revealed the appearance of disorder and new phonon modes in the lattice. The variations in characteristic modes 1GaN i.e. E-2(high) and A(1)(LO), observed for different implanted samples is discussed in detail. The intensity of nitrogen vacancy related vibrational modes appearing at 363 and 665 cm(-1) was observed for samples having different fluences. A gallium vacancy related mode observed at 277/281 cm(-1) for TM ions implanted at 5 x 10(14) cm(-2) disappeared for all samples implanted with rest of fluences. The fluence dependent production of implantation induced disorder and substitution of TM ions on cationic sites is discussed, which is expected to provide necessary information for the potential use of these materials as diluted magnetic semiconductors in future spintronic devices. (c) 2015 Elsevier Ltd. All rights reserved.