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Crystalline resorcinol [C6H4(OH)2] has been shown to amorphize at 40 kbars, solely using Raman scattering. The external modes vanish resulting in a spectrum similar to the density of states spectrum, but the internal modes persist indicating a breakdown of translational and orientational correlation between the molecules. The amorphous state recrystallizes after the pressure is released. We also provide additional information on the known a to P phase transition.

High pressure behavior of adamantane is investigated up to pressures of 26 GPa at ambient temperature using Raman spectroscopy. A detailed study of changes in the Raman spectrum of the C–H stretching modes across the disorder–order transition around 0.5 GPa is reported. Pressure dependence of the internal mode frequencies suggest two more subtle transitions around 2.8 GPa and 8.5 GPa, respectively, which are reversible. Evolution of spectra at higher pressures show evidence for another structural transition above 24 GPa.

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Aspherical optical lenses with spatially varying curvature are desired for capturing high quality, aberration free images in numerous optical applications. Conventionally such lenses are prepared by multistep top-down processes which are expensive, time-consuming, and prone to high failure rate. In this context, an alternate method is presented here based on arrested spreading of a sessile drop of a transparent, cross-linkable polymeric liquid on a solid substrate heated to an elevated temperature. Whereas surface tension driven flow tends to render it spherical, rapid cross-linking arrests such flow so that nonequilibrium aspherical shapes are attained. It is possible to tune also the initial state of the drop via delayed pinching of a liquid cylinder which precedes its release on the substrate. This method has led to the generation of a wide variety of optical lenses, ranging from spherical plano convex to superspherical solid immersion to exotic lenses not achieved via conventional methods.