2.6.1 Microscópios de Transmissão (TEM)
1) FEI TECNAI G2 STwin, canhão LaB6, câmera CCD Gatan Orius (14 bits, 2048x2048 pixeis) e o sistema de precessão ASTAR (Nanomegas) - Laboratório de Caracterização Estrutural (DEMa, UFSCar).
2.7 Referências
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Capítulo 3
Resultados
O sistema utilizado para a implementação do cálculo rPDF+ PED foi uma amostra de nanopartículas de Au0.70Ag0.30 sintetizadas na fonte de clusters presente no grupo [1], como foi
descrito em detalhe no capítulo anterior. A partir de imagens de TEM obtemos um diâmetro médio das NPs de aproximadamente 6 nm. Ao fim de comparação, foram medidos diagramas de difração tipo SAED comum e PED (ângulo de precessão φ = 2°), ambas as medidas foram realizadas exatamente na mesma região da amostra (ver exemplo na Fig. 3.1b).
Figura 3.2: a) Imagem da amostra de Au0.70Ag0.30; é possível observar um estágio inicial de coalescência e uma
distribuição no tamanho das nanopartículas. b) diagrama de difração SAPED de um conjunto de nanopartículas (aproximadamente um total de 2000 NPs, determinado pelo diâmetro da abertura de seleção de área).