1. Department of Chemistry; Federal University of Paraná (UFPR), Centro Politécnico; P.O. Box 19032, Curitiba CEP 81531-980 Brazil
2. Department of Materials Science and Technology; Institute for the Development of Technology, LACTEC; P.O. Box 19067, Curitiba 81531-990 PR Brazil
3. Department of Physics; Federal University of Paraná (UFPR); Curitiba Brazil