INVESTIGADORES
PIERELLA Liliana Beatriz
artículos
Título:
Beta zeolite modified with cobalt: structural and magnetic characterization
Autor/es:
HÉCTOR R. BERTORELLO, PAULA G. BERCOFF, LILIANA B. PIERELLA, SOLEDAD RENZINI AND CLARA SAUX
Revista:
MATERIALS CHEMISTRY AND PHYSICS
Editorial:
ELSEVIER SCIENCE SA
Referencias:
Lugar: Amsterdam; Año: 2014
ISSN:
0254-0584
Resumen:
Beta zeolites were synthesized by the hydrothermal crystallization method obtaining finalparticles of mean size of 20 nm. Cobalt was incorporated after synthesis by ion-exchange, reaching a1.72 wt% as confirmed by ICP. According to XRD and FTIR results, the produced Co-Beta presents highpurity and cristallinity. Our DRS UV-vis results showed the presence of three absorption bandscorresponding to typical α-, β-, γ-types due to low coordination Co2+ ions. The magnetic behavior ofthe materials was evaluated by Zero Field-Cooling/Field-Cooling curves and hysteresis loops atdifferent temperatures, showing Curie constants that vary with T. A complex structure of particles andconglomerates originates different contributions to the observed magnetic response at differenttemperatures. At 4K, the contribution of the smallest particles is explained in terms of the Co2+ ions inthe zeolite structure and magnetocrystalline interactions.
