High-pressure x-ray scattering and computer simulation studies of density-induced polyamorphism in silicon

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dc.contributor.author Daisenberger, Dominik
dc.contributor.author Wilson, Myra Scott
dc.contributor.author Wilding, Martin C.
dc.contributor.author Machon, Denis
dc.contributor.author Cabrera, Raul Quesada
dc.date.accessioned 2010-01-19T10:57:54Z
dc.date.available 2010-01-19T10:57:54Z
dc.date.issued 2007-06-28
dc.identifier.citation Daisenberger , D , Wilson , M S , Wilding , M C , Machon , D & Cabrera , R Q 2007 , ' High-pressure x-ray scattering and computer simulation studies of density-induced polyamorphism in silicon ' Physical Review B: Condensed Matter and Materials Physics , vol 75 , no. 22 , 224118 . en
dc.identifier.issn 1098-0121
dc.identifier.other PURE: 143643
dc.identifier.other dspace: 2160/3997
dc.identifier.uri http://hdl.handle.net/2160/3997
dc.description Wilson, M., Wilding, M. C., Daisenberger, D., Machon, D., Cabrera, R. Q. (2007). High-pressure x-ray scattering and computer simulation studies of density-induced polyamorphism in silicon. Physical Review B: Condensed Matter and Materials Physics, 75 (22). Sponsorship: ESRF en
dc.description.abstract A low- to high-density pressure-driven phase transition in amorphous silicon is investigated by synchrotron x-ray diffraction in the diamond anvil cell. Complementary atomistic molecular dynamics computer simulations provide insight into the underlying structural transformations and allow us to interpret the structure factors obtained from experiment. During compression the form of the scattering function S(Q) changes abruptly at 13.5 GPa, indicating significant structural rearrangement in the amorphous solid. In particular, the first peak in S(Q) shifts to larger Q values. The changes are correlated with the occurrence of a low- to high-density (LDA-HDA) polyamorphic transition observed previously using Raman scattering and electrical conductivity measurements. The data are analyzed to provide real space (pair distribution function) information. The experimental data are compared with results from molecular dynamics (MD) simulations using a modified Stillinger-Weber many-body potential energy function in order to extract structural information on the densified amorphous material. We deduce that the polyamorphic transition involves an abrupt increase in the proportion of 5- and 6-coordinate Si atoms. The overall structure of the HDA polyamorph can be related to that of the LDA form by creation of highly-coordinated "defects" within the tetrahedrally-bonded LDA network. However classical and quantum MD simulations indicate that an even higher density amorphous state might exist, based on structures that resemble the densely-packed metallic polymorphs of crystalline Si. en
dc.format.extent 11 en
dc.language.iso eng
dc.relation.ispartof Physical Review B: Condensed Matter and Materials Physics en
dc.subject RANGE ORDER en
dc.subject GE en
dc.subject PHASE-TRANSITION en
dc.subject MOLECULAR-DYNAMICS SIMULATIONS en
dc.subject GERMANIUM en
dc.subject POROUS SILICON en
dc.subject SUPERCOOLED LIQUID SILICON en
dc.subject DISORDERED PHASES en
dc.subject NEUTRON-DIFFRACTION en
dc.subject PURE AMORPHOUS-SILICON en
dc.title High-pressure x-ray scattering and computer simulation studies of density-induced polyamorphism in silicon en
dc.type Text en
dc.type.publicationtype Article (Journal) en
dc.identifier.doi http://dx.doi.org/10.1103/PhysRevB.75.224118
dc.contributor.institution Materials Research en
dc.contributor.institution Department of Computer Science en
dc.contributor.institution Institute of Mathematics & Physics (ADT) en
dc.description.status Peer reviewed en


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