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You searched for +publisher:"Universidade Estadual de Campinas" +contributor:("Sartorelli, Maria Luisa"). Showing records 1 – 2 of 2 total matches.

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Universidade Estadual de Campinas

1. Caron, Luana. Da s?ntese e do efeito magnetocal?rico de compostos derivados do Fe2P, Mn2Sb e MnAs .

Degree: 2008, Universidade Estadual de Campinas

Resumo: Nesta tese de doutoramento s?o apresentados os resultados do estudo das propriedades magn?ticas, magnetocal?ricas e estruturais de algumas s?ries de compostos que s?o de interesse para aplica??o em refrigera??o magn?tica baseada no efeito magnetocal?rico. Os m?todos de prepara??o da s?rie MnFe P1-xAsx s?o estudados de forma a otimizar o tempo de prepara??o e as propriedades magn?tocal?ricas. Uma nova s?rie de compostos baseada na anterior, a MnFeGe1-xSix foi descoberta, apresentando transi??es de fase magn?tica de segunda ordem e uma varia??o linear dos par?metros de rede em fun??o da concentra??o de Si no intervalo 0 ? x ? 0,7. Tamb?m foi descoberto, associado ? uma transi??o magn?tica de segunda ordem, o efeito magnetocal?rico no composto MnFeSn cujo TC situa-se em torno da temperatura ambiente. Foi feito o estudo do efeito magnetocal?rico dos compostos baseados no Mn2Sb com o Mn parcialmente substitu?do por Cr, V, Co e Cu e o Sb substitu?do por Ge. Nestes compostos uma transi??o do tipo Exchange Inversion ? induzida pelas substitui??es, transformando o estado ferrimagn?tico em antiferromagn?tico em baixa temperatura, dando origem ao chamado efeito magnetocal?rico inverso. Ainda foi desenvolvido um modelo fenomenol?gico para descrever tal transi??o e o efeito magnetocal?rico associado. Por fim ? reportado o efeito magnetocal?rico colossal nos compostos M n1-xCux As, devido ao qual os m?todos de medida magn?ticos do efeito magnetocal?rico s?o revistos. A partir dos resultados em diferentes procedimentos de medida, ? proposta uma forma de medir o efeito em materiais altamente hister?ticos que n?o leva a resultados esp?rios; Abstract: On this PhD thesis some results on the magnetic, magnetocaloric and structural properties of some series of compounds suitable for applications on magnetocaloric effect-based refrigeration are presented. The FeMnP1-xAsx series preparation methods are studied in order to optimize their magnetocaloric properties as well as to shorten its preparation time. A new series of compounds based on the previous one was studied, the MnFeGe1-xSix. These compounds present a second-order magnetic phase transition and a linear change in lattice parameters with Si content on the 0 ? x ? 0.7 range. Also associated with a second-order phase transition, the magnetocaloric effect on FeMnSn was discovered around room-temperature. A careful study of Mn2Sb-based compounds with Mn partially substituted by Cr, V, Co and Cu and Sb by Ge was performed. On these compounds an Exchange Inversion transition is induced by substitutions taking the material from the ferrimagnetic to the antiferromagnetic state with decreasing temperature, giving rise to the so-called inverse magnetocaloric effect. A phenomenological theoretical model was also developed to describe such transitions and their associated magnetocaloric effect. Finally we report on the colossal magnetocaloric effect on Cu-substituted MnAs compounds. Due to this compound?s unusual behavior, the magnetic measurements of the magnetocaloric effect are… Advisors/Committee Members: Gama, Sergio, 1949- (advisor), Bruck, Ekkes (advisor), Sartorelli, Maria Luisa (committee member), Jardim, Renato de Figueiredo (committee member), Moraes, M?rio Ant?nio Bica de (committee member), Lima, Oscar Ferreira de (committee member).

Subjects/Keywords: Efeito magnetocal?rico; Materiais baseados em metais de transi??o; Refrigera??o magn?tica

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Caron, L. (2008). Da s?ntese e do efeito magnetocal?rico de compostos derivados do Fe2P, Mn2Sb e MnAs . (Thesis). Universidade Estadual de Campinas. Retrieved from http://repositorio.unicamp.br/jspui/handle/REPOSIP/277089

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Caron, Luana. “Da s?ntese e do efeito magnetocal?rico de compostos derivados do Fe2P, Mn2Sb e MnAs .” 2008. Thesis, Universidade Estadual de Campinas. Accessed February 23, 2020. http://repositorio.unicamp.br/jspui/handle/REPOSIP/277089.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Caron, Luana. “Da s?ntese e do efeito magnetocal?rico de compostos derivados do Fe2P, Mn2Sb e MnAs .” 2008. Web. 23 Feb 2020.

Vancouver:

Caron L. Da s?ntese e do efeito magnetocal?rico de compostos derivados do Fe2P, Mn2Sb e MnAs . [Internet] [Thesis]. Universidade Estadual de Campinas; 2008. [cited 2020 Feb 23]. Available from: http://repositorio.unicamp.br/jspui/handle/REPOSIP/277089.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Caron L. Da s?ntese e do efeito magnetocal?rico de compostos derivados do Fe2P, Mn2Sb e MnAs . [Thesis]. Universidade Estadual de Campinas; 2008. Available from: http://repositorio.unicamp.br/jspui/handle/REPOSIP/277089

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Universidade Estadual de Campinas

2. Morais, Edival de. Estudo da oxigena??o dos compostos intermet?licos Fe17R2 (R=Sm, Pr, Nd) .

Degree: 1999, Universidade Estadual de Campinas

Resumo: Neste trabalho foi estudada a oxigena??o dos compostos Fe17R2, com R = Sm, Pr e Nd. Amostras em p? dos tr?s compostos foram oxigenadas, por rea??o g?s - s?lido, num reator do tipo Sieverts nas temperaturas de 225, 250, 300, 400, 500, 600, 700 e 800o C. Os tratamentos abaixo de 300o C foram destinadas ao estudo da primeira camada de difus?o do oxig?nio e ? obten??o de uma eventual fase ?xido intersticial, Fe17R2Ox; an?loga ? fase nitreto: a concentra??o de oxig?nio na primeira camada, o perfil (qualitativo) dessa concentr??o durante a oxigena??o e os padr?es de difus?o em diferentes temperaturas foram determinados. As amostras oxigenadas acima de 300o C foram destinadas ? identifica??o dos produtos da decomposi??o da fase 17 - 2 original pelo oxig?nio: foram detectados nove ?xidos, seis dos quais puderam ser identificados. As amostras foram caracterizadas por metalografia ?ptica (OM), difra??o de raios X (XRD), an?lise termomagn?tica (TMA), espectroscopia M?ssbauer (MS), an?lise t?rmica diferencial (DTA) e an?lise termogravim?trica (TGA); Abstract: In this work the oxidation of the compounds Fe17R2 with R = Sm, Pr and Nd, was studied. Powder samples of the three compounds were oxidized, by gas - solid reaction, in a Sieverts type reactor, at temperatures of 225, 250, 300, 400, 500, 600, 700 and 800 °C. The treatments below 300 °C were made to study the first diffusion layer and for trying to get an eventual interstitial oxidized fase, Fe17R2Ox; similar to the nitrided fase: the oxygen concentration in the first diffusion layer for samples fully oxidized, a qualitative oxygen concentration profile in the first layer of samples partially oxidized and the diffusion patterns for different oxidizing temperatures were determined. The samples oxidized above 300 °C were destined to the identification of decomposition products of the original 17 - 2 fase by the oxygen. Nine oxides were detected, six of which were identified. The samples were characterized by optical metallography (OM), X - ray diffractiion (XRD), thermomagnetic analyses (TMA), M?ssbauer spectroscopy (MS), differential thermoanalyses (DTA) and thermogravimetric analyses (TGA) Advisors/Committee Members: Gama, Sergio, 1949- (advisor), Ardisson, Jose Domingos (committee member), Sartorelli, Maria Luisa (committee member), Gandra, Fl?vio C?sar Guimar?es (committee member), Cabral, Francisco de Assis Olimpio (committee member).

Subjects/Keywords: Materiais magn?ticos; Propriedades magn?ticas; Ligas de ferro

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Morais, E. d. (1999). Estudo da oxigena??o dos compostos intermet?licos Fe17R2 (R=Sm, Pr, Nd) . (Thesis). Universidade Estadual de Campinas. Retrieved from http://repositorio.unicamp.br/jspui/handle/REPOSIP/277131

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Morais, Edival de. “Estudo da oxigena??o dos compostos intermet?licos Fe17R2 (R=Sm, Pr, Nd) .” 1999. Thesis, Universidade Estadual de Campinas. Accessed February 23, 2020. http://repositorio.unicamp.br/jspui/handle/REPOSIP/277131.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Morais, Edival de. “Estudo da oxigena??o dos compostos intermet?licos Fe17R2 (R=Sm, Pr, Nd) .” 1999. Web. 23 Feb 2020.

Vancouver:

Morais Ed. Estudo da oxigena??o dos compostos intermet?licos Fe17R2 (R=Sm, Pr, Nd) . [Internet] [Thesis]. Universidade Estadual de Campinas; 1999. [cited 2020 Feb 23]. Available from: http://repositorio.unicamp.br/jspui/handle/REPOSIP/277131.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Morais Ed. Estudo da oxigena??o dos compostos intermet?licos Fe17R2 (R=Sm, Pr, Nd) . [Thesis]. Universidade Estadual de Campinas; 1999. Available from: http://repositorio.unicamp.br/jspui/handle/REPOSIP/277131

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.