J. Phys. IV France 05 (1995) C2-281-C2-286
X-Ray Powder Diffraction Study of the R-Phase in a Ti50Ni48Fe2 Alloy by a New Calibration MethodG. Airoldi1, G. Carcano2, G. Riva3 and M. Vanelli1
1 Dipartimento di Fisica, Universita' di Milano, via Celoria 16, 20133 Milano, Italy
2 ITM-CNR, Area della Ricerca di Milano, via Bassini 15, 20133 Milano, Italy
3 INFM, Unita di Milano Universita', via Celoria 16, 20133 Milano, Italy
The R-phase in a polycrystalline 50Ti48Ni2Fe shape memory alloy has been here investigated by X-Ray Powder counter Diffractometry (XRPD). With the aim to determine the R-phase lattice parameters accurately, an original XRPD calibration method, specifically apt for shape memory alloys, has been developed. The intrinsic aberrations that affect the XRPD have been taken into account by evaluating the XRPD spectrum of the high temperature b.c.c. phase. The correction function Δ(2θ) has been calculated and applied to the R-phase diffraction peaks. A full indexing of the X-ray spectrum of the R-phase, not achievable by raw experimental data, has thus been obtained and the lattice parameters calculated on a set of reflections in un-aberrated angular positions with an accuracy of ≈part in 10000. The calibration method here developed can be used also in the XRPD study of crystalline materials that undergo a first solid-solid phase transition.
© EDP Sciences 1995