Abstract
The lattice expansion of a small piece of Ni (85wt%)-Cr (15wt%) thin film was measured by means of in-situ High Temperature X-ray Diffraction (HTXRD), referring to Ni-Cr plate of the same composition. The experimentally obtained coefficient of linear expansion of the film, β=1.42×10-5/K, was consistent with the β-value of the reference plate. Furthermore, the derived value β=1.40×10-5/K, based on the Vegard rule, was correspondent with the β-value of the film. It was confirmed that HTXRD is a remarkable technique for measuring β-values of tiny samples which cannot be measured by conventional dilatometry. The crystal structure, peak separation, and the factors of XRD peak transformation during temperature elevation of HTXRD are also discussed.
