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Previous issue date: 2014-03-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / No presente trabalho foram sintetizados comp?sitos, a partir da moagem de altaenergia dos precursores hidroxiapatita - HAp (Ca10(PO4)6(OH)2) e ferro met?lico (?-Fe),com o intuito de serem utilizados em hipertermia magn?tica no tratamento do c?ncer. Osprodutos da moagem foram caracterizados por difratometria de raios X (DRX),microscopia eletr?nica de varredura (MEV), espectroscopia de energia dispersiva (EDS),medidas de magnetiza??o em fun??o do campo aplicado e medidas de temperatura emfun??o do campo alternado. Os DRX das amostras batidas de HAp/Fe revelaram somente apresen?a dos precursores. O MEV mostrou aglomerados com formatos irregulares. Ascurvas de magnetiza??o obtidas apresentam casos t?picos de comportamentoferromagn?tico fraco. Para as amostras batidas e submetidas a tratamento t?rmico asseguintes fases foram identificadas: HAp (Ca10(PO4)6(OH)2) , hematita (Fe2O3) e ferrofosfato tric?lcio, FeTCP, Ca19Fe2 (PO4)14. Analisando os resultados de M x H, verificou-seuma redu??o na magnetiza??o de satura??o, tendo em vista que o Fe foi incorporado ?HAp. As curvas de histerese, obtidas a 300 K, s?o caracter?sticas de amostras que possuemmais de uma fase. Em 77 K, o comportamento da curva de histerese ? influenciado pelapresen?a da hematita que ? antiferromagn?tica. J? em T = 4,2K, ? observado umcomportamento ferromagn?tico fraco. Al?m disso, verifica-se o efeito de ?exchange bias?.Os resultados obtidos das medidas de temperatura em fun??o do campo alternado s?opromissores para aplica??es em hipertermia magn?tica e outras aplica??es biom?dicas. / In this work, composites were prepared using high energy mechanical milling from
the precursors hydroxyapatite - HAp (Ca10(PO4)6(OH)2) and metallic iron ( -Fe ). The main
goal here is to study composites in order to employ them in magnetic hyperthermia for cancer
therapy. The produced samples were characterized by X-ray di raction (XRD), scanning
electron microscopy (SEM), energy dispersive spectroscopy (EDS), magnetization curves as
a function of applied eld (MxH), and nally measurements of magnetic hyperthermia. The
XRD patterns of the milled samples HAp/Fe revealed only the presence of precursor materials.
The SEM showed clusters with irregular shapes. The magnetization curves indicated
typical cases of weak ferromagnetic behavior. For samples submitted to grinding and annealing,
the identi ed phases were: HAp (Ca10(PO4)6(OH)2), hematite (Fe2O3) and Calcium
Iron Phosphate (Ca9Fe(PO4)7). Analyzing the results of MxH, there was a reduction of the
saturation magnetization, given that the Fe was incorporated into HAp. Hysteresis curves obtained
at 300 K are characteristics of samples possessing over a phase. At 77 K, the behavior
of the hysteresis curve is in uenced by the presence of hematite, which is antiferromagnetic.
Already at T = 4.2 K, it is observed a weak ferromagnetic behavior. Furthermore, there is
the e ect of exchange bias. Regarding the magnetic hyperthermia, the results of temperature
measurements as a function of the alternating eld are promising for applications in magnetic
hyperthermia and other biomedical applications.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/19377 |
| Date | 14 March 2014 |
| Creators | Santos, Wellington Cantanhede dos |
| Contributors | 78609801420, http://lattes.cnpq.br/2148858591663240, Bohn, Felipe, 99793628049, http://lattes.cnpq.br/9522788035526763, Dantas, Ana Lucia, 78604303472, http://lattes.cnpq.br/7211312864602492, Medeiros, Suzana N?brega de |
| Publisher | Universidade Federal do Rio Grande do Norte, PROGRAMA DE P?S-GRADUA??O EM F?SICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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