NONEQUILIBRIUM CRYSTALLINE PHASES FORMED IN THE CO-TA SYSTEM BY ION-BEAM MIXING

作者:ZHANG ZJ*; LIU BX
来源:Journal of Physics: Condensed Matter , 1994, 6(43): 9065-9074.
DOI:10.1088/0953-8984/6/43/011

摘要

Co-rich Co-Ta solid solutions of the high-temperature Co FCC structure were synthesized by 200 keV room-temperature xenon ion mixing. The experimental results revealed that these FCC solid solutions were formed gradually from the Co hexagonal solid solutions through a HCP --> FCC transition, that the solid solubility was greatly beyond the equilibrium value up to 20 at.% Ta, and that their lattice parameters followed the prediction of Vegard's law. Interestingly, a new metastable crystalline phase of FCC structure with a = 4.43 angstrom was formed in two Ta-rich films, i.e. Co30Ta70 and Co25Ta75 multilayered films, at different irradiation stages. The thermal stabilities of the Co-rich and the Ta-rich metastable crystalline phases were also studied by thermal annealing.