1. Department of Materials Science and EngineeringIQMAAB, Universidad Carlos III de Madrid 28911 Leganes Madrid Spain
2. Department of Electric EngineeringUniversidad Carlos III de Madrid 28911 Leganes Madrid Spain
3. Department of ChemistryUniversidad de Navarra 31080 Pamplona Navarra Spain
4. Universidad Nacional Autónoma de Nicaragua Managua Nicaragua