1. Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-Carlense 400, São Carlos, São Paulo 13566-590, Brazil
2. Nippon Electric Glass Co., Ltd., 7-1, Seiran 2-chome, Otsu, Shiga 520-8639, Japan
3. Department of Material Science, University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga 522-8533, Japan
4. Institut für Physikalische Chemie, WWU Münster, Corrensstraße 28-30, 48149 Münster, Germany