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http://hdl.handle.net/11422/25750
| Type: | Dissertação |
| Title: | Aperfeiçoando as Propriedades de Imãs Permanentes de SmCo5 |
| Author(s)/Inventor(s): | Carvalho, Tainara Coutinho de |
| Advisor: | Simão, Renata Antoun |
| Abstract: | Filmes finos Sm-Co, com estequiometria nominal SmCo5, foram depositados, por pulverização catódica, sobre substrato de Si (1 0 0) com diferentes camadas buffer (Cu, Cr e Ta). A microestrutura e as propriedades magnéticas foram investigadas. Os valores de coercividade dos filmes Sm-Co, com buffer de Cr e Cu, mostraram-se semelhantes aos do HC relatado anteriormente na literatura (cerca de 1 T). No entanto, nos filmes depositados com camada buffer de Ta, a coercividade excedeu 4 T. Depósitos de Sm-Co, à temperatura ambiente, em camadas Ta com diferentes espessuras, seguidas de diferentes tratamentos térmicos, (TT) foram realizadas. A difração de raios X (DRX), a espectroscopia de energia dispersiva (EDS) e a análise magnética mostram a fase SmCo7, para filmes com TT a temperaturas superiores à 550oC e espessura de Ta superior a 30 nm. A difusão de Ta na estrutura de SmCo7 parece ser o responsável pelas propriedades magnéticas duras desses filmes. |
| Abstract: | Sm-Co thin films, with nominal stoichiometry SmCo5, where deposited, by sputtering, on Si substrate (1 0 0) with different buffer layers (Cu, Cr and Ta). The microstructure and the magnetic properties were investigated. The coercivity values of Sm-Co films, with Cr and Cu buffers were similar to the HC previously reported in the literature (about 1 T). However, in films deposited on Ta buffer, the coercivity exceeded 4 T. Deposition of Sm-Co, at room temperature on Ta layers with different thickness, followed by different thermal treatments (TT) were made. The X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and magnetic analysis show a SmCo7 phase in films with TT at temperatures greater than 550oC, and Ta thickness greater than 30 nm. The Ta diffusion in SmCo7 structure seems to be the responsible to the hard magnetic properties of these films. |
| Keywords: | Imãs permanentes Coercividade Sm-Co |
| Subject CNPq: | CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA::METALURGIA FISICA |
| Program: | Programa de Pós-Graduação em Engenharia Metalúrgica e de Materiais |
| Production unit: | Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia |
| Publisher: | Universidade Federal do Rio de Janeiro |
| Issue Date: | Mar-2020 |
| Publisher country: | Brasil |
| Language: | por |
| Right access: | Acesso Aberto |
| Appears in Collections: | Engenharia Metalúrgica e de Materiais |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 943190.pdf | 1.25 MB | Adobe PDF | View/Open |
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