1. Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02-668 Warsaw, Poland
2. Division of Superconductivity and Magnetism, Felix Bloch Institute for Solid State Physics, Universitat Leipzig, Linnéstrasse 5, D-04103 Leipzig, Germany
3. Instituto Federal do Rio Grande do Sul, Campus Vacaria, 95200-000 Vacaria, RS, Brazil