Formation, characterization and magnetic properties of some ternary Al-Cu-M (M = transition metal) quasicrystals prepared by conventional solidification
- Univ. of Patras (Greece). Engineering Science Dept.
The author presents a new semi-empirical criterion responsible for the formation and stability of the quasicrystalline state of conventionally solidified ternary Al{sub 80-x}Cu{sub 20}M{sub x} (M = Ru, Rh, Re, Ir) alloys with x = 7.5, 15, 20 at.%. Generally he found that decagonal (D-phase) and icosahedral (I-phase) quasicrystals exist in neighboring composition ranges, when one of the reported criteria examined in terms of average valence electron concentration (e/a) and effective atomic radius ratio (a{sub eff}) is fulfilled. By conventional cooling decagonal and icosahedral quasicrystals were formed in all the systems, with the exception of the Al-Cu-Re system, where only crystalline phases were found. In the ternary Al-Cu-Ir system he found large (1--1.3 mm) and stable D- and I-phases. Further on, magnetic susceptibility and magnetization curves of the alloys were investigated i n the temperature range from 5 to 300 K and for magnetic fields between {minus}50 kOe {le} H {le} 50 kOe. On the basis of the resulting magnetic susceptibility curves he found that in the range of 20--300 K the magnetic susceptibility is temperature independent for all samples. On the contrary, in the range of 5--20 K the magnetic susceptibility is temperature dependent, with the exception of the samples I-Al{sub 65}Cu{sub 20}Ru{sub 15}, D-Al{sub 65}Cu{sub 20}Rh{sub 15}, D-Al{sub 65}Cu{sub 20}Ir{sub 15} and D-Al{sub 60}Cu{sub 20}Rh{sub 20}.
- OSTI ID:
- 566553
- Journal Information:
- International Journal of Modern Physics B, Vol. 11, Issue 20; Other Information: PBD: 10 Aug 1997
- Country of Publication:
- United States
- Language:
- English
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