Banca de DEFESA: NEYMAR PEREIRA DA COSTA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : NEYMAR PEREIRA DA COSTA
DATA : 14/09/2017
HORA: 15:00
LOCAL: Auditório do DFTE
TÍTULO:

PROPRIEDADES TERMOELÉTRICAS DE FILMES NANOMÉTRICOS DE LIGAS DE TELURIO SELENIO E ANTIMONIO PRODUZIDOS POR MAGNETRON SPUTTERING DC.

PALAVRAS-CHAVES:

Target, Bismuth Telluride, Thermoelectric, Seebeck Coefficient, Figure of Merit.

PÁGINAS: 92
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
SUBÁREA: Física da Matéria Condensada
RESUMO:

The present thesis discusses a semiconductor target production method whose material is obtained from commercial thermoelectric modules. The targets are used in a magnetron sputtering system. The materials consist of two semiconductor ternary alloys, one made of bismuth telluride and antimony, characterized as type P and the other of bismuth selenide and telluride, characterized as type N. These alloys of Bi₂Te_3-ySe_y and Bi_2-xSb_xTe₃ systems exhibit high-performance thermoelectric properties within an ambient temperature range. Based on these data, thermoelectric films of nanometric thickness were produced in two batches, whose samples were submitted to post-production thermal treatments. We investigated the thermoelectric properties of films, at ambient temperature in the physical property measurement system (PPMS). To that end, the thermal transport option (TTO), which makes it possible to acquire data on physical quantities such as Seebeck coefficient α, thermal conductivity κ and electrical resistivity ρ, was applied. These quantities were used to calculate the power factor and figure of merit, which is an adimensional factor that determines how promising the material is for energy conversion and thermoelectric refrigeration applications. Measures of voltage current using the four-point collinear method showed that the type P semiconductor can be used as a thermal keying sensor. An important perspective is the development of a substrate, using films as planar thermoelements, thereby functioning as a thermoelectric device capable of promoting thermal gradients in applications for other systems such as magnetic-galvanometric.

MEMBROS DA BANCA:
Interno - 1509949 - ALEXANDRE BARBOSA DE OLIVEIRA
Presidente - 2199774 - CARLOS CHESMAN DE ARAUJO FEITOSA
Externo à Instituição - CHARLIE SALVADOR GONCALVES - UFPB
Externo à Instituição - CLÁUDIO BENEDITO SILVA FURTADO - UFPB
Interno - 1675199 - SUZANA NOBREGA DE MEDEIROS