Role of interface in ion mixing or thermal annealing induced amorphization in multilayers in some immiscible systems
- Tsinghua Univ., Beijing (China). Dept. of Materials Science and Engineering
Six binary metal systems were selected to study the possibility of forming amorphous alloys by ion mixing or thermal annealing in multilayered films, i.e. the Ta-Cu, Zr-Nb, Zr-Ta, Y-Zr, Y-Mo and Y-Ta systems, featuring positive heats of formation ({Delta}H{sub f}) ranging from +3 to +40 kJ/mol. Firstly, the interfacial free energy consisting of a chemical and an elastic terms was calculated and added to the energetic state of the multilayers. It was found that the excess interfacial free energy increased with increasing the fraction of the interfacial atoms in the multilayers, and could raise the multilayers to an energy level intersecting with or being higher than that of the amorphous phase possessing a typical convex shape. It is therefore possible to produce amorphous alloys in such systems, if the multilayered films included enough fraction of the interfacial atoms. The multilayered samples were then designed and prepared accordingly and both ion mixing and thermal annealing under appropriate conditions resulted in the formation of a number of new amorphous alloys, confirming the above prediction based on the interfacial free energy concern. It is noted that the success of synthesizing amorphous alloys by solid-state reaction in the immiscible systems develops a new glass forming technique, namely interface-generated spontaneous amorphization, which has a great potential to produce new and relatively thick amorphous films, e.g. a Ta{sub 72}Cu{sub 28} amorphous film of 800 nm thick was obtained.
- Sponsoring Organization:
- National Science Council, Taipei (Taiwan, Province of China)
- OSTI ID:
- 477380
- Report Number(s):
- CONF-951155-; ISBN 1-55899-299-5; TRN: 97:009395
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 27 Nov - 1 Dec 1995; Other Information: PBD: 1996; Related Information: Is Part Of Ion-solid interactions for materials modification and processing; Poker, D.B. [ed.] [Oak Ridge National Lab., TN (United States)]; Ila, D. [ed.] [Alabama A and M Univ., Normal, AL (United States)]; Cheng, Y.T. [ed.] [General Motors Corp., Warren, MI (United States)]; Harriott, L.R. [ed.] [AT and T Bell Labs., Murray Hill, NJ (United States)]; Sigmon, T.W. [ed.] [Arizona State Univ., Tempe, AZ (United States)]; PB: 923 p.; Materials Research Society symposium proceedings, Volume 396
- Country of Publication:
- United States
- Language:
- English
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