Crystal phase identification

A method for determining the crystalline phase and crystalline characteristics of a sample, comprising:

• obtaining a backscattered electron Kikuchi pattern of a sample;
• determining the location of lines on said Kikuchi pattern;
• extracting from the Kikuchi pattern widths and angles of said lines;
• extracting d-spacings of said lines;
• determining an approximate unit cell volume;
• obtaining chemical composition information about the sample;
• determining compounds from a database that match the chemical composition information and approximate unit cell volume, said database containing crystallography data;
• obtaining line angles of said matched compounds from the database crystallography data;
• and
• comparing said line angles calculated from the database crystallography data for said matched compounds with the angles extracted from the Kikuchi pattern of the sample to identify a phase match and determine the crystalline phase and crystalline characteristics of said sample.

An apparatus for determining crystallographic characteristics of a sample, comprising:

• an electron beam generator for generating an electron beam;
• an image collection system for obtaining an backscattered electron Kikuchi pattern of a crystalline particle of a sample, said pattern being produced by the illumination of said sample by said electron beam;
• and
• means for processing said backscattered electron Kikuchi pattern to obtain an indexing solution for said crystalline particle, said means for processing being in data communication with said image collection system and comprising an algorithm to obtain said backscattered electron Kikuchi pattern of said sample, to determine the location of the lines on said Kikuchi pattern, to extract from the Kikuchi pattern line widths and angles of said lines, to extract d-spacings of said lines, to determine an approximate unit cell volume, to obtain chemical composition information, determine compounds from a database that match the chemical composition information and approximate unit cell volume, said database containing crystallography data, to calculate line angles of said matched compounds from the database crystallography data, and to compare said line angles calculated from the database crystallography data for said matched compounds with the angles extracted from the Kikuchi pattern of the sample to identify a phase match and determine the crystalline phase and crystalline characteristics of said sample.