Autor(es): Rocha, Leandro S.R. ; Amoresi, Rafael A.C. [UNESP] ; Moreno, Henrique [UNESP] ; Ramirez, Miguel A. [UNESP] ; Ponce, Miguel A. ; Foschini, Cesar R. [UNESP] ; Longo, Elson ; Simões, Alexandre Z. [UNESP]
Data: 2020
Identificador Persistente: http://hdl.handle.net/11449/201897
Origem: Oasisbr
Made available in DSpace on 2020-12-12T02:44:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-06-30
The modification of CeO2 with rare-earth elements opens up a wide range of applications as biomedical devices using infrared emission as well as magnetic and gas-sensing devices, once the structural, morphological, photoluminescent, magnetic, electric, and gas-sensing properties of these systems are strongly correlated to quantum electronic transitions between rare-earth f-states among defective species. Quantitative phase analysis revealed that the nanopowders are free from secondary phases and crystallize in the fluorite-type cubic structure. Magnetic coercive field measurements on the powders indicate that the substitution of cerium with lanthanum (8 wt %), in a fluorite-type cubic structure, created oxygen vacancies and led to a decrease in the fraction of Ce species in the 3+ state, resulting in a stronger room-temperature ferromagnetic response along with high coercivity (160 Oe). In addition to the magnetic and photoluminescent behavior, a fast response time (5.5 s) was observed after CO exposure, indicating that the defective structure of ceria-based materials corresponds to the key of success in terms of applications using photoluminescent, magnetic, or electrical behaviors.
Department of Chemistry Federal University of São Carlos (UFSCar)
School of Engineering Sao Paulo State University (UNESP)
Institute of Materials Science and Technology Investigation (INTEMA)
School of Engineering Sao Paulo State University (UNESP)
