Influence of Nd Doping on the Properties of SrTiO3 thin Films Synthesized by PLD on Different Substrates

SrTiO3, SrTi0.99Nd0.01O3 and Sr0.99Nd0.01TiO3 thin films were synthesized by pulsed laser deposition at 700 °C on different substrates (silica, R-sapphire, (100) LaAlO3 and (100) MgO). The influence of Nd3+ substitution into the A and B sites of SrTiO3 perovskite on film growth was studied. The films were characterized by X-ray diffraction (–2, - and φ-scans), micro-Raman spectroscopy, UV–Vis spectroscopy and field-emission scanning electron microscopy. All of the films exhibited a (h00) orientation and high-quality epitaxial growth on LaAlO3. The films grown on MgO, with the exception of the SrTi0.99Nd0.01O3 film, also exhibited a (h00) orientation. The polycrystallinity of the SrTi0.99Nd0.01O3 film may be related to the increased lattice distortion when Ti4+ was replaced with Nd3+. A polycrystalline growth was observed for all of the films deposited on silica and R-sapphire, as expected. The Raman results showed that Nd doping led to an increase in the short-range disorder. The morphology strongly depended on the nature of the substrate and on Nd doping, specially in the case of SrTi0.99Nd0.01O3.