![]() ![]() Method of bonding single crystal quartz by field-assisted bondingĬurlee, Richard M. NMR results from single crystal studies may be more applicable to natural systems. powder) and different shock loading histories. The difference in results between this study and that of Cygan and others is most likely caused by different starting materials ( single crystal vs. Our NMR results differ substantially from those of Cygan and others and suggest that the proposed shock wave barometer may require refinement. These results are expanded by studying single crystal quartz shocked to 12 and 33 GPa using the 6.5 m two-stage light-gas gun at Lawrence Livermore National Laboratories. J.Ĭygan and others report a broadening of the Si-29 nuclear magnetic resonance (NMR) peak for synthetic quartz powders with increasing shock pressure which they propose as a shock wave barometer for natural systems. NMR spectroscopy of experimentally shocked single crystal quartz: A reexamination of the NMR shock barometerįiske, P. The H2O weakening by this process is of a disequilibrium nature and thus depends on the amount of H2O available. Cracking and crack healing play an important role in the recycling process and imply a close interrelationship between brittle and crystal plastic deformation. The deformation processes in these crystals represent a recycling of H2O between FI´s, dislocation generation at very small fluid inclusions, incorporation of structurally bound H into dislocation cores, and release of H2O from dislocations back into FI´s during recovery. The H2O weakening effect in our FI-bearing natural quartz crystals is assigned to the processes of dislocation generation and multiplication at small FI´s. This band is polarized and represents structurally bound H, its H-content is estimated to be 1-3% of the total H2O-content and appears to be associated with dislocations. The 3585 cm-1 band is reduced or even disappears after annealing. In addition, there is a discrete absorption band at 3585 cm-1, which only occurs in deformed regions. Strongly deformed regions show FTIR spectra with a pointed broad absorption band in the ~3400 cm-1 region as a superposition of molecular H2O bands and three discrete absorption bands (at 3367, 3400, and 3434 cm-1). Sample deformation occurs by dominant dislocation glide on selected slip systems, accompanied by some dynamic recovery. During subsequent deformation, the size of FI´s is further reduced (down to ~10 nm). Cracks heal and small neonate FI´s form, increasing the number of FI´s drastically. During pressurization many FI´s decrepitate. The starting material is milky quartz, consisting of dry quartz (H2O contents of <150 H/106Si) with fluid inclusions (FI). Natural single crystals of quartz have been experimentally deformed in two orientations: (1) normal to one prism-plane, (2) In O+ orientation at temperatures of 9Â☌, pressures of 1.0 and 1.5 GPa, and strain rates of ~1 x 10-6s-1. Water weakening in experimentally deformed milky quartz single crystals after the fused quartz has crystallized, and maintaining these conditions until crystal growth in the upper zone is completed. DELTA.T sufficient to increase material transport between the zones and rapid crystallization.alpha.- Quartz single crystal can thus be made from fused quartz in caustic solvent by heating to 350.degree. The heating rate is then increased to maintain a large. DELTA.T between the warmer lower zone and cooler upper zone until the amorphous substance is transformed to the crystalline state in the lower zone. The apparatus loaded with the substance, solvent, and seed crystals is heated slowly maintaining a very low. The process is carried out in an autoclave having a lower dissolution zone and an upper crystallization zone between which a temperature differential (.DELTA.T) is maintained at all times. Using this approach, we demonstrate quartz nanomechanical cantilevers and ring resonators featuring Qs of 49, respectively.Ī process for growing single crystals from an amorphous substance that can undergo phase transformation to the crystalline state in an appropriate solvent. Here, we show that the Faraday cage angled-etching technique can be used to realize nanoscale electromechanical and photonic devices in quartz. Owing to the fact that an integrated thin-film based quartz platform is not available, most of these applications rely on macroscopic, bulk crystal-based devices. Single-crystal α- quartz, one of the most widely used piezoelectric materials, has enabled a wide range of timing applications. Sohn, Young-Ik Miller, Rachel Venkataraman, Vivek LonÄar, Marko Mechanical and optical nanodevices in single-crystal quartz ![]()
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