Expressions for spinodal wavelength in orthorhombic and tetragonal structure systems

摘要

Daniel and Lipson's expression [1], used for determining spinodal wavelength of the modulated structure, is stated to be general. This is derived for simple cubic, bcc or fee, decomposition in the (10 0) direction. Incremental change (δh) is taken in the h index to derive the expression. The end product may be of any crystal structure, but the initial alloy should be cubic. Expressions are needed when the decomposition is from other crystal structures. Suitable modifications in the expressions are also required to be carried out to take into account the direction of modulations.