J.F. Liu

Atomic structure of Al89La6Ni5 metallic glass

Atomic structures of amorphous Al(89)La(6)Ni(5), prepared by single-roller melt spinning, and pre-annealed at 493 and 588xa0K for 1xa0h, were characterized by differential scanning calorimetry, x-ray diffraction with a large wavevector transfer value, La L(3)-edge and Ni K-edge x-ray absorption fine structure and the reverse Monte Carlo technique. In the as-prepared amorphous alloy, our study reveals that the Ni-Al distance is 2.38 ± 0.02xa0Å coupled with a coordination number as low as 6.2. The Al-Al distance was found to be ∼4.5% shorter than the nominal atomic diameter of aluminium and the coordination number to be ∼39% less than expected from the dense random packing model. Crystallization of the Al(89)La(6)Ni(5) glassy alloy at high temperatures can be described as follows: [amorphous alloy] [Formula: see text] [fcc-Al] + [bcc-(AlLa)] + residual amorphous [Formula: see text] [fcc-Al] + [o-Al(3)Ni ] + [o-La(3)Al(11) ].

Compression behavior and phase transition of cubic In2O3 nanocrystals

High-pressure behaviors of bixbyite-type cubic In2O3 nanocrystals with an average grain size of 6.0 nm and bulk In2O3 samples were investigated by in situ high-pressure synchrotron radiation x-ray diffraction measurements up to 40 GPa at ambient temperature. It was found that nanosized and bulk samples began to transform from cubic into hexagonal structure at about 15–25 GPa and extended up to 40 GPa. Both cubic and hexagonal phases remained after pressure release. Below the onset transition pressure, the nanosized samples were harder to compress with a larger bulk modulus of 296.06 GPa than the bulk samples with a bulk modulus of 178.87 GPa.

High-pressure structural behaviour of nanocrystalline Ge

The equation of state and the pressure of the I?II transition have been studied for nanocrystalline Ge using synchrotron x-ray diffraction. The bulk modulus and the transition pressure increase with decreasing particle size for both Ge-I and Ge-II, but the percentage volume collapse at the transition remains constant. Simplified models for the high-pressure structural behaviour are presented, based on the assumption that a large fraction of the atoms reside in grain boundary regions of the nanocrystalline material. The interface structure plays a significant role in affecting the transition pressure and the bulk modulus.

Atomic structure of Al(89)La(6)Ni(5) metallic glass.

Atomic structures of amorphous Al(89)La(6)Ni(5), prepared by single-roller melt spinning, and pre-annealed at 493 and 588xa0K for 1xa0h, were characterized by differential scanning calorimetry, x-ray diffraction with a large wavevector transfer value, La L(3)-edge and Ni K-edge x-ray absorption fine structure and the reverse Monte Carlo technique. In the as-prepared amorphous alloy, our study reveals that the Ni-Al distance is 2.38 ± 0.02xa0Å coupled with a coordination number as low as 6.2. The Al-Al distance was found to be ∼4.5% shorter than the nominal atomic diameter of aluminium and the coordination number to be ∼39% less than expected from the dense random packing model. Crystallization of the Al(89)La(6)Ni(5) glassy alloy at high temperatures can be described as follows: [amorphous alloy] [Formula: see text] [fcc-Al] + [bcc-(AlLa)] + residual amorphous [Formula: see text] [fcc-Al] + [o-Al(3)Ni ] + [o-La(3)Al(11) ].

Atomic structure of Al89La6Ni5metallic glass

Atomic structures of amorphous Al(89)La(6)Ni(5), prepared by single-roller melt spinning, and pre-annealed at 493 and 588xa0K for 1xa0h, were characterized by differential scanning calorimetry, x-ray diffraction with a large wavevector transfer value, La L(3)-edge and Ni K-edge x-ray absorption fine structure and the reverse Monte Carlo technique. In the as-prepared amorphous alloy, our study reveals that the Ni-Al distance is 2.38 ± 0.02xa0Å coupled with a coordination number as low as 6.2. The Al-Al distance was found to be ∼4.5% shorter than the nominal atomic diameter of aluminium and the coordination number to be ∼39% less than expected from the dense random packing model. Crystallization of the Al(89)La(6)Ni(5) glassy alloy at high temperatures can be described as follows: [amorphous alloy] [Formula: see text] [fcc-Al] + [bcc-(AlLa)] + residual amorphous [Formula: see text] [fcc-Al] + [o-Al(3)Ni ] + [o-La(3)Al(11) ].