S?ntese e caracteriza??o de nanopart?culas magn?ticas do sistema bin?rio sam?rio cobalto

• Main Author: Concei??o Filho, Raimundo Nazareno da Silva
• Other Authors: 24150720444
• Language: Portuguese
• Published: PROGRAMA DE P?S-GRADUA??O EM F?SICA 2017
• Subjects: CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA; M?todo Poliol; Sistema sam?rio cobalto; Nanopart?culas magn?ticas; ?cido ac?tico
• Online Access: https://repositorio.ufrn.br/jspui/handle/123456789/24270

Submitted by Automa??o e Estat?stica ([e-mail]) on 2017-11-01T22:37:28Z No. of bitstreams: 1 RaimundoNazarenoDaSilvaConceicaoFilho_DISSERT.pdf: 12242083 bytes, checksum: 01e4da6c38f0cf877f871a80f9e59811 (MD5) === Approved for entry into archive by Arlan Eloi Leite Silva ([e-mail]) on 2017-11-14T00:09:04Z (GMT) No. of bitstreams: 1 RaimundoNazarenoDaSilvaConceicaoFilho_DISSERT.pdf: 12242083 bytes, checksum: 01e4da6c38f0cf877f871a80f9e59811 (MD5) === Made available in DSpace on 2017-11-14T00:09:04Z (GMT). No. of bitstreams: 1 RaimundoNazarenoDaSilvaConceicaoFilho_DISSERT.pdf: 12242083 bytes, checksum: 01e4da6c38f0cf877f871a80f9e59811 (MD5) Previous issue date: 2017-09-01 === Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) === Neste trabalho utilizamos o m?todo qu?mico poliol para a prepara??o de nanopart?culas de Sm-Co. As amostras sintetizadas foram nomeadas das seguintes formas: ARS-0%; ARS-5%;ARS-7% e ARS-9%, sendo as porcentagens referente a varia??o do ?cido Ac?tico utilizado na s?ntese. A caracteriza??o estrutural foi realizada via difra??o de raio-X e microscopia eletr?nica de transmiss?o (MET). Os par?metros estruturais foram determinados pelo m?todo de Rietvelt utilizando o software Maud. As seguintes fases foram identificadas: Sm2Co7; Sm2Co17 e Sm5Co19. Para o estudo das propriedades magn?ticas, medidas com o magnet?metro de amostra vibrante foram utilizadas para obten??o de curvas de magnetiza??es em fun??o do campo magn?tico aplicado ? temperatura ambiente. O PPMS foi utilizado para medir curvas de magnetiza??o em fun??o da temperatura. As temperaturas de Curie obtidas est?o de acordo com as fases obtidas pelos m?todos de caracteriza??o estrutural. Foram obtidas imagens das amostras atrav?s do MEV e MET para estudo morfol?gico e determina??o do tamanho das nanopart?culas das amostras. Nossos resultados mostram a viabilidade do m?todo poliol para obten??o de nanopart?culas de Sm-Co e a influencia do ?cido Ac?tico no processo de s?ntese. === In this work we used the chemical polyol method for the preparation of Sm-Co nanoparticles. The synthesized samples were named in the following forms: ARS-0%; ARS-5%, ARS-7% and ARS-9%, being the percentages referring to the variation of Acetic Acid used in the synthesis. The structural characterization was performed by X-ray diffraction and transmission electron microscopy (TEM). The structural parameters were determined by the Rietvelt method using the Maud software. The following phases were identified: Sm2CO7; Sm2Co17 and Sm5Co19. For the study of magnetic properties, measurements with the vibrating sample magnetometer were used to obtain magnetization curves as a function of the magnetic field applied at room temperature. The PPMS was used to measure magnetization curves as a function of temperature. The Curie temperatures obtained are in accordance with the phases obtained by the structural characterization methods. Images of the samples were obtained through the SEM and MET for morphological study and determination of the size of the nanoparticles of the samples. Our results show the feasibility of the polyol method to obtain Sm-Co nanoparticles and the influence of Acetic Acid in the synthesis process.