Banca de DEFESA: ÁDILA PRISCILLA GOMES RODRIGUES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ÁDILA PRISCILLA GOMES RODRIGUES
DATA : 22/07/2019
HORA: 09:30
LOCAL: Auditório do NUPPRAR
TÍTULO:

SYNTHESIS AND CHARACTERIZATION OF DOUBLE PEROVSKITES WITH STOICHIOMETRY La2CrBO6 WITH B = Fe, Co AND Ni - DETERMINATION OF THEIR MAGNETIC PROPERTIES

PALAVRAS-CHAVES:

Perovskites Doubles. Synthesis Via Gelatin. Magnetic Properties

PÁGINAS: 70
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Inorgânica
ESPECIALIDADE: Físico Química Inorgânica
RESUMO:

The metal oxides have various interesting physical properties ranging from, for example, ferroelectricity, colossal magnetoresistance until superconductivity, occupying therefore an outstanding position in the modern technological stage. The perovskite structure is the basis of a large number of oxides containing transition metals that exhibit these varied physical properties. This work proposes to obtain and characterize double perovskite stoichiometry with La2CrB'O6 (B '= Co, Fe and Ni) and to study the effect of the transition metals Co, Fe and Ni in their magnetic properties. The materials were obtained by gelatin synthesis. The synthesis process by this method is novel and is a variation of the sol-gel method in which the alkoxide precursors are replaced by gelatin. This method has the advantage that gelatin is a low cost and non-toxic material. The method uses metal nitrates using commercial gelatin as an organic precursor. The synthesized material was characterized by X-ray diffraction (XRD) using the Rietveld refinement of the method, scanning electron microscopy (SEM) and their magnetic characteristics were obtained by Mossbauer spectroscopy and magnetization measurements. The results of the XRD, combined with the refinement, showed the formation of perovskite phases and secondary phases in all the samples. Hysteresis curves and magnetic measurements revealed different temperature dependent magnetism behaviors.

MEMBROS DA BANCA:
Presidente - 349770 - DULCE MARIA DE ARAUJO MELO
Externa à Instituição - JOANNA ELZBIETA KULESZA - UFPE
Externo ao Programa - 350830 - JOSE HUMBERTO DE ARAUJO
Externa ao Programa - 1979301 - RENATA MARTINS BRAGA
Externo à Instituição - RODRIGO CÉSAR SANTIAGO - UFERSA