| Texto completo | |
| Autor(es): |
Correa, Leonardo M.
;
Ortega, Eduardo
;
Ponce, Arturo
;
Cotta, Monica A.
;
Ugarte, Daniel
Número total de Autores: 5
|
| Tipo de documento: | Artigo Científico |
| Fonte: | ULTRAMICROSCOPY; v. 259, p. 13-pg., 2024-02-07. |
| Resumo | |
The association of scanning transmission electron microscopy (STEM) and detection of a diffraction pattern at each probe position (so-called 4D-STEM) represents one of the most promising approaches to analyze structural properties of materials with nanometric resolution and low irradiation levels. This is widely used for texture analysis of materials using automated crystal orientation mapping (ACOM). Herein, we perform orientation mapping in InP nanowires exploiting precession electron diffraction (PED) patterns acquired by an axial CMOS camera. Crystal orientation is determined at each probe position by the quantitative analysis of diffracted intensities minimizing a residue comparing experiments and simulations in analogy to x-ray structural refinement. Our simulations are based on the two-beam dynamical diffraction approximation and yield a high angular precision (-0.03 degrees), much lower than the traditional ACOM based on pattern matching algorithms (-1 degrees). We anticipate that simultaneous exploration of both spot positions and high precision crystal misorientation will allow the exploration of the whole potentiality provided by PED-based 4D-STEM for the characterization of deformation fields in nanomaterials. (AU) | |
| Processo FAPESP: | 14/01045-0 - Estudo por técnicas avançadas de microscopia eletrônica de agregados metálicos e materiais nanocompósitos utilizados em aplicações fotovoltaicas |
| Beneficiário: | Daniel Mario Ugarte |
| Modalidade de apoio: | Bolsas no Exterior - Pesquisa |
| Processo FAPESP: | 19/07616-3 - Novos catalisadores e controle de direcionalidade em nanofios semicondutores do tipo III-V |
| Beneficiário: | Mônica Alonso Cotta |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| Processo FAPESP: | 15/16611-4 - Nanofios semicondutores do tipo III-V: estudos de síntese voltados para aplicações em biologia |
| Beneficiário: | Mônica Alonso Cotta |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |