Implementation of interactive exit wave reconstruction algorithm by HRTEM focal serie images

• Grant number: 07/07357-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2008
• End date: December 31, 2008
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Antonio José Ramirez Londono
• Grantee: Fellipe Grillo Peternella
• Host Institution: Associação Brasileira de Tecnologia de Luz Síncrotron (ABTLuS). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil

Abstract

In order to get important information at the nanometric scale, transmission electron microscopy shows to be an efficient tool. However, during image formation in the microscope, several undesirable effects occur. Some examples are: spherical aberration of objective lenses and noise addition, which microscopists must correct or live with. The goal of this project is to implement an algorithm to reconstruct the exit wave function and to use it to avoid the spherical aberration effect. The exit wave reconstruction algorithm is based on the focal series, which is a set of images recorded at different objective lens focus value. The research group where this project will be developed already has experience with the use of Meyer et al. algorithm for exit wave reconstruction, which requires about 15 to 20 images to perform the wave reconstruction. The IWFR (Iterative Wave Function Reconstruction) algorithm proposed by Allen et al., which needs a reduced number of images, will be implemented in this work. This algorithm facilitates the electrons exit wave function reconstruction, especially in specimens sensitive to the electron beam. Both reconstruction methods (Meyer et al and Allen et al) will be compared. Finally, they would be also developed noise filtering (before the wave function reconstruction) and image alignment procedures. (AU)