title: Accurate determination of lattice parameters based on Niggli reduced cell theory by using digitized electron diffraction micrograph.
abstract: 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 Ba4Ti13O30showed that the maximum errors are 1.6% for lengths and are 0.3% for angles.
authors.affiliation: School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.affiliation: School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China.
authors.forename: Canying
authors.initials: C
authors.lastname: Cai
authors.affiliation: School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Lin
authors.affiliation: School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China.
authors.forename: Lunjun
authors.initials: L
authors.lastname: Gong
authors.affiliation: School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China. Electronic address: yqb@xtu.edu.cn.
authors.forename: Qibin
authors.initials: Q
authors.lastname: Yang
keywords: Electron diffraction; Niggli reduced cell; Unit-cell determination