Annealing of BaTiO3 thin films after heavy ion implantation

Abstract

Single crystalline BaTiO3 films have been grown by pulsed laser deposition on SrTiO3. Radioactive I I I in ions were implanted with energies of 60 and 400 keV, respectively. The lattice site of(111) In has been determined by emission channeling of conversion electrons emitted after the nuclear decay to Cd-111. Besides a large random fraction, 11(3)% of the events show that In substitutes Ti-sites directly after the implantation. The recovery of the lattice after the implantation has been monitored in the direct vicinity of the probes by perturbed angular correlation (PAC) spectroscopy in a wide temperature range. After annealing in air at a temperature of 1420 K for 10 min, PAC spectroscopy yields a unique electric field gradient at the site of the In-111(Cd-111)-probe with a quadrupole coupling constant of 28.7(5) MHz and a frequency distribution with a width of 4.2(2) MHz. The film starts to degrade at a temperature of 1520 K. Scanning electron microscopy and energy dispersive X-ray spectroscopy investigations have been used to monitor the degradation. (C) 2003 Elsevier B.V. All rights reserved.