Estudo das propriedades estruturais e elétricas de nanocompósitos (Cu₅₀Mn₂₅Sn₂₀Al₅)₁₋ₓ(ZnO)ₓ

• Ano de defesa: 2025
• Autor(a) principal: Lima, Ariely Vitória Bezerra
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Engenharia de Materiais; Programa de Pós-Graduação em Ciência e Engenharia de Materiais; UFPB
• Palavras-chave em Português: Materiais termoelétricos; Ligas Heusler; Óxido de zinco; Nanocompósitos; Sinterização; Thermoelectric materials; Heusler Alloys; Zinc oxide; Nanocomposites; Sintering; CNPQ::ENGENHARIAS
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/123456789/37512

This work aimed to investigate the effect of zinc oxide (ZnO) addition on the structural, thermal, electrical, and microstructural properties of the Full-Heusler alloy Cu₅₀Mn₂₅Sn₂₀Al₅, seeking to understand the modifications induced by varying the ZnO content. The samples were obtained by induction melting, followed by characterization through X-ray diffraction (XRD) with Rietveld refinement, scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM/EDS), density and porosity analyses using the Archimedes method, and thermoelectric measurements. The results indicated that small additions of ZnO favored the formation of metallic phases such as martensite and austenite and reduced the presence of simple oxides, whereas higher contents promoted the formation of complex oxides, affecting the stability and toughness of the material. The thermoelectric measurements revealed a characteristic behavior of materials with a negative temperature coefficient (NTC), with ZnO acting as an effective structural and electrical modifier. In general, the results demonstrate that the addition of ZnO modifies the balance between metallic and oxide phases, influencing the structural and electrical properties of the alloy according to the incorporated content and processing conditions.