Method of determining lattice constant, method of evaluating material by using the same and electronic microscope suitable for using the same

Abstract

The invention provides a method of determining a lattice constant of an arbitrary material such as a polycrystalline material speedily and easily, and a method of evaluating the stress and strain of the material speedily. According to the invention, the lattice constant of a standard sample is varied within a predetermined range and finds the HOLZ line pattern of the standard sample by calculation using an equation (y=f(x, a)=α(a)x+β(a)) and the data of the pattern is accumulated to form a data library. On the other hand, a test sample to be measured is irradiated and scanned with a convergent electron beam. Then, a developing HOLZ line pattern is compared with the HOLZ line pattern in the data library and the most similar HOLZ line pattern is selected. From the data of the lattice constant of the data library having the most similar HOLZ line pattern, the lattice constant of the test sample to be measured is determined. Moreover, the distribution state of the stress and strain of the test sample to be measured can be two-dimensionally mapped by the use of the lattice constant determined in this manner.