Method for reconstructing unknown nanophase Bravais lattice by single crystal electron diffraction patterns

Abstract

The invention relates to a method for reconstructing a unknown nanophase Bravais lattice by single crystal electron diffraction patterns, comprising the following steps of: selecting a characteristic parallelogram from an obtained nanophase single crystal electron diffraction pattern; measuring electron diffraction data of nanophase, and determining vector of an intersection line of two 2D (two-dimensional) reciprocal surfaces; solving lattice parameters of a reciprocal lattice after 3D (three-dimensional) reconstruction; selecting a 3D reciprocal primitive cell, and performing reduction process to obtain the reciprocal Bravais lattice of a unknown crystal. In the invention, a transmission electronic microscope and a double-tilting sample stage thereof are adopted, and the electron diffraction technology is adopted to resolve the Bravais lattice of a unknown crystal only by any two continuously tilted orthodiagonal single crystal electron diffraction patterns in situ of the nanophase crystal, so the invention can be used for determining Bravais lattice and parameters of any crystal system. The adopted electron diffraction technology comprises selected area electron diffraction pattern and electron diffraction pattern. The invention is particularly suitable for the situations incapable of simultaneously obtaining a plurality of single crystal electron diffraction patterns.

Description

technical field [0001] The invention relates to a method for reconstructing an unknown nano-phase Bravais lattice by a single crystal electron diffraction pattern, and belongs to the technical field of material microstructure characterization and crystal structure analysis. Background technique [0002] Common methods for determining the Bravais lattice of unknown crystals include X-ray diffraction and electron diffraction. The former is suitable for analyzing bulk and powder samples, and the measurement accuracy of interplanar spacing is relatively high, but the disadvantage is that the diffraction results reflect the sample Structural information of all phases inside, when the sample contains multiple constituent phases inside, this method cannot separate the diffraction peaks of each phase; the latter uses single crystal selected area electron diffraction or microdiffraction in transmission electron microscopy, the biggest advantage of electron diffraction While studying ...

AI Technical Summary

Problems solved by technology

More importantly, even if the operator of the transmission electron microscope has enough patience and spends a lot of time trying to obtain its series of electron diffraction patterns by tilting and repositioning the same nanoparticle, the object being characterized after long-term exposure to high energy Under the electron beam, its crystal structure may have been destroyed by the radiation, so it is almost impossible to obtain a series of diffraction patterns of crystal particles below 10 nanometers in actual operation

Due to these factors, there is still a lack of practical and feasible characterization methods for analyzing the lattice of unknown nanophases.

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