High-pressure x-ray diffraction of icosahedral Zr-Al-Ni-Cu-Ag quasicrystals

The effect of pressure on the structural stability of icosahedral Zr-Al-Ni- Cu-Ag quasicrystals forming from a Zr65Al7.5Ni10Cu7.5Ag10 metallic glass wi th a supercooled liquid region of 44 K has been investigated by in situ hig h-pressure angle-dispersive x-ray powder diffraction at ambient temperature using synchrotron radiation. The icosahedral quasicrystal structure is ret ained up to the highest hydrostatic pressure used (approximately 28 GPa) an d is reversible after decompression. The bulk modulus at zero pressure and its pressure derivative of the icosahedral Zr-Al-Ni-Cu-Ag quasicrystal are 99.10+/-1.26 GPa and 4.25+/-0.16, respectively. The compression behavior of different Bragg peaks is isotropic and the full width at half maximum of e ach peak remains almost unchanged during compression, indicating no anisotr opic elasticity and no defects in the icosahedral Zr-Al-Ni-Cu-Ag quasicryst als induced by pressure. (C) 2001 American Institute of Physics.