Accurate determination of lattice parameters based on Niggli reduced cell theory by using digitized electron diffraction micrograph

作者：Yang, Yi; Cai, Canying; Lin, Jianguo; Gong, Lunjun; Yang, Qibin^*

来源：Micron, 2017, 96: 9-15.

DOI：10.1016/j.micron.2016.12.006

• Niggli reduced cell
• Unit-cell determination
• Electron diffraction

In this paper, we used Niggli reduced cell theory to determine lattice constants of a micro/nano crystal by using electron diffraction patterns. The Niggli reduced cell method enhanced the accuracy of lattice constant measurement obviously, because the lengths and the angles of lattice vectors of a primitive cell can be measured directly on the electron micrographs instead of a double tilt holder. With the aid of digitized algorithm and least square optimization by using three digitized micrographs, a valid reciprocal Niggli reduced cell number can be obtained. Thus a reciprocal and real Bravais lattices are acquired. The results of three examples, i.e., Mg4Zn7, an unknown phase (Precipitate phase in nickel-base superalloy) and Ba4Ti13O30 showed that the maximum errors are 1.6% for lengths and are 0.3% for angles.

• 出版日期2017-5
• 单位湘潭大学