Workshops

 

22º Workshop SEMAT/UM - Caracterização Avançada de Materiais

 

Electron Backscatter Diffraction on Thin Films

 

Download apresentação: Difração de Eletrões Retrodifundidos (EBSD).pdf (5.7MB)

Data: Segunda feira, 30 de maio 2016
Hora: 2:30 pm,

Lugar: Anfiteatro EA2.05, Edif. Escola de Arquitectura da Universidade do Minho em Azurém

Abstract: Electron backscatter diffraction (EBSD) coupled with scanning electron microscope (SEM) is a powerful tool for the microstructural and crystallographic characterization applied to a wide range of materials. EBSD measurements need specific geometrical configurations in the SEM, especially a high tilt angle (70°) between the surface of the specimen and the primary electron beam, to promote a high level of backscattered electron emission. These backscattered electrons can be diffracted by crystal lattice planes of the sample surface according to Bragg´s law, giving rise to a diffraction pattern, called Kikuchi pattern, which can be interpreted as a gnomonic projection of the crystal lattice. Each band corresponds to a distinct crystallographic plane and the interception of bands leads to poles directly related to principal directions of the crystal. The width of the Kikuchi band increases with the decreasing of the interplanar spacing, since the angular width of a Kikuchi band is twice of the Bragg angle. EBSD has become a standard investigations method to quantitatively analyse the microstructure especially for metals and alloys. In this talk, EBSD investigations on ZnO thin films deposited by sputtering will be presented, as well as on other thin film systems.

Palestrante: Cibeli Garcia, Centre of Physics, University of Minho