Open AccessParticle size and convergent electron diffraction patterns of triangular prismatic gold nanoparticles
Author(s) -
Clemente Fernando-Marquez,
G. MondragónGalicia,
Lourdes Bazán-Díaz,
J. ReyesGasga
Publication year - 2021
Publication title -
revista mexicana de física/revista mexicana de física
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.181
H-Index - 25
eISSN - 2683-2224
pISSN - 0035-001X
DOI - 10.31349/revmexfis.67.041005
Subject(s) - electron diffraction , stacking , materials science , diffraction , crystallography , particle (ecology) , symmetry (geometry) , kikuchi line , condensed matter physics , molecular physics , reflection high energy electron diffraction , optics , chemistry , physics , geometry , nuclear magnetic resonance , geology , oceanography , mathematics
Convergent beam diffraction (CBED) patterns of nanoparticles are possible. CBED of triangular prismatic shaped Au nanoparticle with focus on diffraction pattern symmetry and forbidden reflections observed along [111] and [112] zone axes are reported in this work. It is well known that the CBED patterns of nanoparticles of 30 nm or less in size only show bright kinematical discs. The dynamic contrast with Kikuchi and sharp HOLZ lines within the bright discs, as observed in CBED of volumetric materials, is well observed in particles larger of 500 nm in size. In addition, it is shown that the 1/3[422] and 1/2[311] weak forbidden reflections observed in the [111] and [112] electron diffraction patterns of these particles do not modify the symmetry of the CBED patterns, but they disappear as the size of the particle increases. The symmetry of the CBED patterns are always observed in concordance with the space group Fm3m (No. 225) of the Au unit cell. The possible explanations for observing forbidden reflections are the incomplete ABC stacking due to surface termination and the stacking faults in the fcc structure.