Kinetics of ordering in Ni_1.50Sn ('Ni₃Sn₂') as revealed by the variation of the lattice parameters upon annealing

Andreas Leineweber (1) , Eric Jan Mittemeijer (2) , Michael Knapp (3) , Carsten Baehtz (4)

1 Department Mittemeijer
2 Max Planck Institute for Metals Research
3 Cells
4 HASYLAB

X-ray powder diffraction was employed to reveal the structural changes occurring upon annealing of quenched, hexagonal Ni_1.50Sn below its equilibrium ordering temperature, leading finally to long-range ordered, orthorhombic Ni_1.50Sn. The changes in the diffraction patterns indicate that the features of the low-temperature phase develop gradually in two main stages. Ex-situ and in-situ time-resolved X-ray powder diffraction analysis of the first stage was employed to monitor at various temperatures in particular the time dependence of the lattice axial ratio c/a associated with the formation of long-range order in small domains. Data evaluation using an 'equivalence-time' method gave a value of 165-170 kJ/mol for the activation energy of the ordering, indicative of lattice-site changes of Ni atoms.

Mots clés: Physical Sciences

Andreas Leineweber, Eric Jan Mittemeijer, Michael Knapp, Carsten Baehtz. Kinetics of ordering in Ni_1.50Sn ('Ni₃Sn₂') as revealed by the variation of the lattice parameters upon annealing. Philosophical Magazine, 2006, 87 (12), pp.1821-1844. ⟨10.1080/14786430601083355⟩. ⟨hal-00513809⟩