Volume 77, Issue 1, January 2006
Index of content:
- CONDENSED MATTER; MATERIALS
The development of a rapid quenching device for the study of the dependence of glass structure on fictive temperature77(2006); http://dx.doi.org/10.1063/1.2162751View Description Hide Description
We have constructed a rapid quenching device with an estimated quench rate of in order to explore the structural changes of glasses formed with varying quench rates. This apparatus quenches the sample in an inert atmosphere and recovers 100% of the sample, allowing the study of small , isotopically enriched samples that can greatly facilitate nuclear magnetic resonance(NMR) studies of nuclei with low natural abundance (such as and ). An -enriched Ca-boroaluminosilicate glass was formed with a high quench rate using this apparatus, and a clear increase in the amount of nonbridging oxygens with increasing quench rate was observed. Additionally, NMR spectra of E-glass samples formed with a wide variety of fictive temperatures showed a decrease in the proportion of in E-glass with increasing fictive temperature, in accordance with previous studies. The changing proportion of present in the E-glass sample with changing quench rate was used as a rough method of confirmation of the calculated quench rate.
77(2006); http://dx.doi.org/10.1063/1.2162453View Description Hide Description
Understanding the elastic and plastic deformationproperties of nanostructured metals requires the development of in situ testing methods that can follow the footprints of the deformation mechanism(s) during mechanical testing. Here we present an in situ synchrotron x-ray-diffraction technique which allows the measurement of diffraction profiles continuously during mechanical testing, providing an in situ peak profile analysis capability. The in situ approach is achieved thanks to the development of a microstrip detector allowing the instantaneous measurement of the diffraction pattern over a range of 60°. This in situ technique allows for the first time a comparison of the footprints of the plastic deformation mechanism during loading and after unloading. The measurements are performed on several types of freestanding dog bones, covering sample thicknesses down to the submicron range.