Microdiffraction Application to short-range order in a quenched copper-platinum alloy

Abstract

The microdiffraction technique has been applied to the problem of short-range-order in quenched CuPt alloy. The microdiffraction patterns agree with the space filling microdomain model proposed from previous dark field electron microscopy. Patterns can be obtained from regions down to about 2 nm in size. Quantitative microdiffraction measurements show that the microdomains are partially ordered, with a value of the Bragg‐Williams parameter S = 0·49 ± 0·03. A value of the Cowley parameter, α₂, can be calculated from this, and it is in good agreement with the value obtained from previous X-ray studies.