Structural changes in amorphous GeS2 at high pressure

TY - JOUR

T1 - Structural changes in amorphous GeS2 at high pressure

AU - Vaccari, M.

AU - Garbarino, G.

AU - Aquilanti, G.

AU - Coulet, M. V.

AU - Trapananti, A.

AU - Pascarelli, S.

AU - Hanfland, M.

AU - Stavrou, E.

AU - Raptis, C.

PY - 2010/1/12

Y1 - 2010/1/12

N2 - High-pressure modifications in glassy GeS2 have been investigated up to 45 GPa using the diamond anvil cell through x-ray absorption fine structure (XAFS) spectroscopy and x-ray diffraction (XRD). The gradual increase in the Ge-S distance of about 0.1Å between 15 and 25 GPa evidenced by XAFS is interpreted as a signature of a coordination increase around Ge. The negative shift of the germanium K absorption edge position is connected to the progressive metallization of the glass. XRD measurements reveal the amorphous-amorphous nature of the structural transformation. The first sharp diffraction peak loses intensity and shifts toward higher Q values in the first few gigapascal, reflecting changes in the intermediate-range order prior to the local coordination increase. The observed changes are reversible after pressure release with strong hysteresis.

AB - High-pressure modifications in glassy GeS2 have been investigated up to 45 GPa using the diamond anvil cell through x-ray absorption fine structure (XAFS) spectroscopy and x-ray diffraction (XRD). The gradual increase in the Ge-S distance of about 0.1Å between 15 and 25 GPa evidenced by XAFS is interpreted as a signature of a coordination increase around Ge. The negative shift of the germanium K absorption edge position is connected to the progressive metallization of the glass. XRD measurements reveal the amorphous-amorphous nature of the structural transformation. The first sharp diffraction peak loses intensity and shifts toward higher Q values in the first few gigapascal, reflecting changes in the intermediate-range order prior to the local coordination increase. The observed changes are reversible after pressure release with strong hysteresis.

UR - http://www.scopus.com/inward/record.url?scp=77954800353&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.81.014205

DO - 10.1103/PhysRevB.81.014205

M3 - 文章

AN - SCOPUS:77954800353

SN - 1098-0121

VL - 81

JO - Physical Review B - Condensed Matter and Materials Physics

JF - Physical Review B - Condensed Matter and Materials Physics

IS - 1

M1 - 014205

ER -