TY - JOUR
T1 - Relaxation and glass transition in an isostatically compressed diopside glass
AU - Wondraczek, Lothar
AU - Behrens, Harald
AU - Yue, Yuanzheng
AU - Deubener, Joachim
AU - Scherer, George W.
PY - 2007/5
Y1 - 2007/5
N2 - Relaxation of isostatically compressed CaMgSi2O6 (diopside) glass is explored by ex situ differential scanning calorimetric (DSC) experiments. A diopside melt was compressed above its glass transition temperature under isostatic conditions at a pressure of 500 MPa. DSC analysis was performed at ambient pressure after slowly cooling the compressed melt under pressure (i.e., after freezing-in the densified state). Compression-induced enhancement of the overshoot in heat capacity was observed in the glass transition region. This indicates that a densified, quenched glass possesses a lower apparent fictive temperature, TfA, than a glass that was cooled under ambient pressure at the same cooling rate. However, a thermodynamic analysis indicates that the fictive temperature produced under pressure, Tf0, is actually much higher than that determined from DSC experiments at ambient pressure (Tf0>TfA).
AB - Relaxation of isostatically compressed CaMgSi2O6 (diopside) glass is explored by ex situ differential scanning calorimetric (DSC) experiments. A diopside melt was compressed above its glass transition temperature under isostatic conditions at a pressure of 500 MPa. DSC analysis was performed at ambient pressure after slowly cooling the compressed melt under pressure (i.e., after freezing-in the densified state). Compression-induced enhancement of the overshoot in heat capacity was observed in the glass transition region. This indicates that a densified, quenched glass possesses a lower apparent fictive temperature, TfA, than a glass that was cooled under ambient pressure at the same cooling rate. However, a thermodynamic analysis indicates that the fictive temperature produced under pressure, Tf0, is actually much higher than that determined from DSC experiments at ambient pressure (Tf0>TfA).
UR - http://www.scopus.com/inward/record.url?scp=34248372008&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34248372008&partnerID=8YFLogxK
U2 - 10.1111/j.1551-2916.2007.01566.x
DO - 10.1111/j.1551-2916.2007.01566.x
M3 - Article
AN - SCOPUS:34248372008
SN - 0002-7820
VL - 90
SP - 1556
EP - 1561
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
IS - 5
ER -