Synthetic Quartz Crystals Research Articles

Cytotoxicity of fractured quartz on THP-1 human macrophages: role of the membranolytic activity of quartz and phagolysosome destabilization

The pathogenicity of quartz involves lysosomal alteration in alveolar macrophages. This event triggers the inflammatory cascade that may lead to quartz-induced silicosis and eventually lung cancer. Experiments with synthetic quartz crystals recently showed that quartz dust is cytotoxic only when the atomic order of the crystal surfaces is upset by fracturing. Cytotoxicity was not observed when quartz had as-grown, unfractured surfaces. These findings raised questions on the potential impact of quartz surfaces on the phagolysosomal membrane upon internalization of the particles by macrophages. To gain insights on the surface-induced cytotoxicity of quartz, as-grown and fractured quartz particles in respirable size differing only in surface properties related to fracturing were prepared and physico-chemically characterized. Synthetic quartz particles were compared to a well-known toxic commercial quartz dust. Membranolysis was assessed on red blood cells, and quartz uptake, cell viability and effects on lysosomes were assessed on human PMA-differentiated THP-1 macrophages, upon exposing cells to increasing concentrations of quartz particles (10–250 µg/ml). All quartz samples were internalized, but only fractured quartz elicited cytotoxicity and phagolysosomal alterations. These effects were blunted when uptake was suppressed by incubating macrophages with particles at 4 °C. Membranolysis, but not cytotoxicity, was quenched when fractured quartz was incubated with cells in protein-supplemented medium. We propose that, upon internalization, the phagolysosome environment rapidly removes serum proteins from the quartz surface, restoring quartz membranolytic activity in the phagolysosomes. Our findings indicate that the cytotoxic activity of fractured quartz is elicited by promoting phagolysosomal membrane alteration.

Luminescence of natural α-quartz crystal with aluminum, alkali and noble ions impurities

Photoluminescence and thermally stimulated luminescence of synthetic and natural (morion and smoky) α-quartz crystals doped with aluminum and alkali ions were studied. The samples were examined both untreated and subjected to substitution of alkali ions for copper or silver ions. The photoluminescence spectrum of the untreated crystals is characterized with the main blue band around 400 nm (~3.1 eV). The corresponding luminescence center is based on a defect containing aluminum and alkali as compensators in natural and synthetic quartz crystals. Photoluminescence is subjected to thermal quenching and can be detected at high temperatures above 700 K, however the main intensity decay takes place at 200 K. The thermal quenching activation energy is 0.15 ± 0.05 eV and the frequency factor is 3·107 s−1. In the samples with silver ions the main luminescence band is located at ~260 nm (~4.7 eV) with a time constant of ~37 μs at 80 K, and in the samples with copper ions the PL band is at ~ 360 nm (~3.4 eV) with a time constant ~ 50 μs at 80 K. The initial luminescence of crystals is greatly reduced after introduction of noble ions. The luminescence of noble ions quenches at 700 K without drop in intensity at 200 K. For luminescence associated with silver the energy of thermal quenching is 0.7 ± 0.1 eV with a frequency coefficient of 1 · 1013 s−1, and for the luminescence related to copper, these parameters are 0.55 ± 0.1 eV and 1 · 1012 s−1. The differences in intra-center luminescence properties of the same defect containing alkali ions or noble ions are based on differences in electronic transitions. In the case of alkali ions the charge transfer transitions between oxygen and alkali ions. In the case of noble ions absorption – luminescence corresponds to intra ion transitions. Radiation properties are related to trapping of an electron on one valence ion. Created atom moves out of aluminum containing defect. The hole remains on aluminum-oxygen defect. Thermally stimulated luminescence is related to release of atom, it diffusion to aluminum defect with the hole on oxygen and following radiative recombination. Optically stimulated luminescence is explained by the similar process of optical release of excited atom and movement to aluminum defect and recombination of electron with hole.

Studying internal structure of quartz by broadband ultrasonic tomography under cyclic compression

The article considers the possibility of studying and identifying defects in the internal structure of synthetic quartz crystals using the parameters of acoustic emission and laser-ultrasound tomography. In the course of cyclic compressive loading, the nature of the propagation of discontinuities in a sample was investigated. It is revealed that the properties of the material, the inhomogeneity of which is associated with the presence of microdefects and anisotropy, change in the initial stages of mechanical load. With repeated application of the load on the sample, previously formed defects cause significant changes in its internal structure. With the help of numerical modeling, the obtained results were verified.

Excellent Crystal Coloration and An Extraordinary Improvements of Developing Synthetic Quartz Single Crystals Growth and Defects

The analysis of the impurity content crystals grown in sodium carbonate solution is carried out using flame technique. Colored crystals have been produced from aqueous solutions of potassium carbonate under laboratory conditions and using a steel autoclave. The seeds were slices cut parallel to the planes (0001). With the impurity of aluminum and irradiation, defective color centers have generated quartz coloration phenomenon. This is occurred on the base of the electrical balance by exchanging aluminum ions with tetravalent silicon ions in the presence of alkali elements (monvalent) i.e. Na+ or Li+ . Interestingly, the current paper introduces a method suggests the utilization of silica-rich rocks to develop the growth of large crystals of synthetic quartz.

Atomic Diffusion Bonding for Optical Devices with High Optical Density

In recent years, high-brightness projector products equipped with laser light sources are widely used for digital cinema, projection mapping, and simulation. Their increased luminance enhances the optical energy density of the optical system, and the strong photon and thermal energies degrade the organic adhesive used in the optical interface. This has come to pose a severe shortcoming affecting the reliability and durability of optical elements used in optical systems. A new bonding method that provides high light transmittance with high bonding strength is necessary for the optical interface of high optical density devices. Atomic diffusion bonding (ADB) of wafers is a promising process to achieve room-temperature wafer bonding: Thin metal films are fabricated using sputter deposition on two flat wafers’ surfaces, with subsequent bonding of the two films on the wafers in vacuum (1,2). Bonding can be done even with film thickness of a few angstroms on each side. Incident light can be transmitted through such thin bonded films without any marked reduction in intensity. The use of thin Ti films is effective to achieve high light transmittance while maintaining high bonding strength to bond oxide wafers such as synthetic quartz crystal (2). However, optical energy absorption of 2% remains at the bonded interface even when the wafers are bonded using 0.2 nm thick Ti film on each side. A reduction of Ti film thickness below 0.2 nm enhances the transmittance further, but it reduces the bonding strength considerably. To enhance the light transmittance at the bonded interface, we propose atomic diffusion bonding using oxide underlayers: After oxide films are deposited on two flat wafers’ surfaces, the wafers are bonded as usual using thin metal films at room temperature using atomic diffusion bonding as shown in figure (A). Oxygen dissociated from oxide layers enhances the formation of Ti oxide; 100% light transmittance at the bonded interface can be achieved by post-bonded annealing in air at low temperatures. Table (B) presents the light transmittance at wavelength λ of 500 nm at the bonded interface for wafers bonded using Ti(0.5 nm) on each side. In the ADB process with oxide underlayer, SiO2 films deposited using ion-assisted vapor deposition were used. The SiO2 layer surface roughness was less than 0.5 nm. In ADB process with SiO2 underlayer, light transmittance at the bonded interface was enhanced considerably from 90% for as-bonded wafers to 100% for wafers annealed at 300 °C. It is noteworthy that this marked enhancement of the light transmittance is applicable to any material wafer. Without an oxide underlayer, enhancement of the light transmittance by annealing is slight: The enhancement for bonded quartz glass wafers, for instance, was from 90% for as-bonded to 91% for annealed even at 500 °C. Moreover, the surface free energy at the bonded interface for quartz glass wafers bonded using SiO2 underlayers was greater than that of wafers without the underlayers, indicating another important merit for ADB processing with an oxide underlayer. This bonding technique is applicable to almost all optical interfaces between mirror-polished surfaces of any material, and is expected to be useful to fabricate optical devices with high optical density such as high-brightness projectors with laser light sources. (1) T. Shimatsu and M. Uomoto, “Atomic diffusion bonding of wafers with thin nanocrystalline metal films,” J. Vac. Sci. Technol., B 28, 706-714 (2010). (2) T. Shimatsu, M. Uomoto, and H. Kon, “Invited: Room Temperature Bonding Using Thin Metal Films (Bonding Energy and Technical Potential),” ECS Transactions, 64(5), 317-328 (2014). Figure 1

Effect of irradiation and thermal annealing on quartz materials luminescence

X-ray and gamma-quanta irradiation of radiation-resistant quartz materials including natural and synthetic quartz crystals and high-purity quartzite causes the luminescence in the ultraviolet range (365 nm), thermally stimulated luminescence and radiofrequency electromagnetic emission. Preliminary radiation and thermal annealing improves luminescence properties of quartz materials.

Characterization of Swept Synthetic High Quality Quartz Crystal

The synthetic quartz crystal is widely utilized in electronic and optical components due to its high frequency and temperature stability, good dielectric properties, low thermal coefficient of linear expansion, and wide range of optical transparency. However, radiation effects due to cosmic rays are responsible for a frequency shift for quartz oscillators in space systems, which impair their performance. Sweeping quartz at high electric field is a well-established method for improving device performance in a radiation environment. The present paper focuses on the voltage current characteristic of swept quartz. First, the sweeping conduction mechanism is ionic conduction. Second, as the voltage increases, the current increases first, then decreases, and then increases. ICP-AES results indicated that the sweeping process make Na+ a oriented locomotion. Third, the etch channel tensity is obviously reduced to less than 3/cm3, which is a very promising result for space applications. Moreover, the radiation resistance properties are improved after electrical sweeping.

Morphological ripening of fluid inclusions and coupled zone-refining in quartz crystals revealed by cathodoluminescence imaging: Implications for CL-petrography, fluid inclusion analysis and trace-element geothermometry

Cathodoluminescence (CL) studies have previously shown that some secondary fluid inclusions in luminescent quartz are surrounded by dark, non-luminescent patches, resulting from fracture-sealing by late, trace-element-poor quartz. This finding has led to the tacit generalization that all dark CL patches indicate influx of low temperature, late-stage fluids. In this study we have examined natural and synthetic hydrothermal quartz crystals using CL imaging supplemented by in-situ elemental analysis. The results lead us to propose that all natural, liquid-water-bearing inclusions in quartz, whether trapped on former crystal growth surfaces (i.e., of primary origin) or in healed fractures (i.e., of pseudosecondary or secondary origin), are surrounded by three-dimensional, non-luminescent patches. Cross-cutting relations show that the patches form after entrapment of the fluid inclusions and therefore they are not diagnostic of the timing of fluid entrapment. Instead, the dark patches reveal the mechanism by which fluid inclusions spontaneously approach morphological equilibrium and purify their host quartz over geological time.Fluid inclusions that contain solvent water perpetually dissolve and reprecipitate their walls, gradually adopting low-energy euhedral and equant shapes. Defects in the host quartz constitute solubility gradients that drive physical migration of the inclusions over distances of tens of μm (commonly) up to several mm (rarely). Inclusions thus sequester from their walls any trace elements (e.g., Li, Al, Na, Ti) present in excess of equilibrium concentrations, thereby chemically purifying their host crystals in a process analogous to industrial zone refining. Non-luminescent patches of quartz are left in their wake. Fluid inclusions that contain no liquid water as solvent (e.g., inclusions of low-density H2O vapor or other non-aqueous volatiles) do not undergo this process and therefore do not migrate, do not modify their shapes with time, and are not associated with dark-CL zone-refined patches.This new understanding has implications for the interpretation of solids within fluid inclusions (e.g., Ti- and Al-minerals) and for the elemental analysis of hydrothermal and metamorphic quartz and its fluid inclusions by microbeam methods such as LA-ICPMS and SIMS. As Ti is a common trace element in quartz, its sequestration by fluid inclusions and its depletion in zone-refined patches impacts on applications of the Ti-in-quartz geothermometer.

Specific Surface Free Energy of As-Grown and Polished Faces of Synthetic Quartz

Contact angles of water droplet on as-grown Z, +X, –X, and m faces of synthetic quartz crystals with growth term of 20 and 48 days, and polished Z, +X, –X, Y, and 45&#176 cut faces of synthetic quartz crystal were observed. The average of the contact angles on as-grown Z, +X, and –X faces increased with the growth term, and they were larger than that on polished Z, +X, and –X faces. On the other hand, the average of the contact angles of water on m face decreased with the growth term, and they were smaller than that on polished Y cut face. Growth rate of the faces of synthetic crystals was measured and the order of growth rate was, m < –X < +X < Z. Specific surface free energy (SSFE) was calculated using Neumann’s equation. The SSFE of polished face was in the order of, m < –X < +X < Z, which corresponds to the order of the growth rate. The SSFE was larger for the face with larger growth rate.

Giant g-factors of natural impurities in synthetic quartz

We report the observation of g-factors of natural paramagnetic impurities in a pure synthetic quartz crystal at milli-Kelvin temperatures. Measurements are made by performing spectroscopy using multiple high-Q whispering gallery modes sustained in the crystal. Extreme sensitivity of the method at low temperatures allows the determination of natural residual impurities introduced during the crystal growth. We observe g-factors that significantly differ from integer multiples of the electron g-factor in vacuum, and with values of up to 7.6, which reveals much stronger coupling between impurities and the crystal lattice than in previous studies. Both substitutional and interstitial ions are proposed as candidates for the observed interactions.

Research on Synthetic Quartz Crystal Quality

The quality of two synthetic quartz crystals, Z lump and Y bar, was researched by the infrared spectrophotometer technology and chemical spectral analysis in this study. The relationships between typical impurity OH and other impurities such as Fe, CO and Mg were discussed which impacted the quality of artificial rock crystal; the defects in artificial rock crystal and crystals, such as lattice dislocation and distortion with a close relation appear at the same time and impact the quality of synthetic quartz. The work in future should begin from the following two aspects in order to improve synthetic quartz crystal quality: the one is to further study the crystal structure characteristics and to explore the cutting type of crystal with convenient cultivation and processing process, high use ratio and high Q value. For example, the research is to make the Z area of Y bar crystals bigger and the other areas smaller or disappear. The other one is to improve the existing technological level and to reduce defects.

A Study of Cathodoluminescence and Trace Element Compositional Zoning in Natural Quartz from Volcanic Rocks: Mapping Titanium Content in Quartz

This article concerns application of cathodoluminescence (CL) spectroscopy to volcanic quartz and its utility in assessing variation in trace quantities of Ti within individual crystals. CL spectroscopy provides useful details of intragrain compositional variability and structure but generally limited quantitative information on element abundances. Microbeam analysis can provide such information but is time-consuming and costly, particularly if large numbers of analyses are required. To maximize advantages of both approaches, natural and synthetic quartz crystals were studied using high-resolution hyperspectral CL imaging (1.2-5.0 eV range) combined with analysis via laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Spectral intensities can be deconvolved into three principal contributions (1.93, 2.19, and 2.72 eV), for which intensity of the latter peak was found to correlate directly with Ti concentration. Quantitative maps of Ti variation can be produced by calibration of the CL spectral data against relatively few analytical points. Such maps provide useful information concerning intragrain zoning or heterogeneity of Ti contents with the sensitivity of LA-ICPMS analysis and spatial resolution of electron microprobe analysis.

Small-angle neutron scattering studies on the structure of radiation defects in neutron-irradiated synthetic quartz

The supra-atomic structure of single crystals of synthetic quartz with a dislocation density of 54 cm−2 in their initial state and after irradiation in a VVR-M reactor by fast neutrons with the energy, En > 0.1 MeV, at fluences of 2.3 × 1019 and 4.5 × 1019 N/cm2, has been studied by the method of small-angle thermal neutron scattering. It has been established that fast neutrons create point, linear, and bulk defects throughout the entire material. It has been shown that extended defects have a significant integral length per volume unit equal to ∼3 × 1011 cm/cm3, and can form a consolidated network in the sample with a cell size of ∼30 nm, through the channels of which the migration of impurity atoms and molecules is possible.

Calibrating Ti concentrations in quartz for SIMS determinations using NIST silicate glasses and application to the TitaniQ geothermobarometer

The recently developed titanium-in-quartz (TitaniQ) geothermobarometer of Wark and Watson (2006) and Thomas et al. (2010) has the potential to be applied to a wide range of igneous and metamorphic rocks. For Ti concentrations > ∼10 ppm, the concentrations can be measured using an electron microprobe, but lower concentrations are below detection limits and require techniques such as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) or secondary ion mass spectrometry (SIMS). SIMS is ideal for this purpose as it maximizes lateral and depth resolution. We used SIMS to analyze synthetic quartz crystals characterized for Ti concentration by electron probe (18–813 ppm Ti) and compare this calibration to the commonly available NIST 61X glasses using both high mass resolution (HMR) and conventional energy filtering (CEF) techniques. We used a primary beam of 16 O – ions and detected positive secondary ions. During HMR sessions, the mass spectrometer was operated at a mass resolving power (M/∆M) of ~2000 to separate molecular ions from elemental Ti peaks. For CEF analyses, the instrument detected secondary ions sputtered from the sample with excess kinetic energies of 75 ± 20 eV. Titanian quartz measurements reveal general homogeneity and a linear increase in Ti + /Si + ion ratios with increasing Ti concentrations. Background signals represent 0–1 ppm. The slopes of the calibration curves for the titanian quartz crystals are ∼70% of the curves constructed using NIST glasses, indicating a much higher ion yield for Ti from the glasses compared to the simple oxide of silicon. We demonstrate, however, that a simple correction factor allows NIST glasses to be used to quantitatively determine the Ti concentrations of quartz (with 3.8% error using HMR, and 8.2% error using CEF) until homogenous, well-characterized samples of SiO2 become

Plastic anisotropy and fabric evolution in sheared and recrystallized quartz single crystals

[1] The effect of a lattice preferred orientation on the flow strength of quartz aggregates dynamically recrystallized from single crystals of synthetic quartz was investigated using general shear experiments in a Griggs apparatus. Experiments were conducted at shear strains (γ) up to 5 at a temperature of 900°C, confining pressure of 1.5 GPa, and shear strain rate of 10−5 s−1. Three starting orientations of crystal were used, to activate three slip systems: basal 〈a〉, prism [c], and prism 〈a〉, although slip-induced rotation of the crystal axes in the first two orientations led to the activation of additional slip systems. For crystals with higher water contents, basal 〈a〉 and prism 〈a〉 orientations are relatively weak and prism [c] orientations are stronger. All three initial crystal orientations undergo dynamic recrystallization with increasing shear strain, although the strain required for 100% recrystallization varies: γ ≈ 2 for prism [c] slip, γ ≈ 3.8 for basal 〈a〉 slip, and γ ≈ 5 for prism 〈a〉 slip. For all three starting orientations, distinct domains of recrystallized grains develop with c axes parallel to Y of the strain ellipsoid (Ymax), replacing recrystallized grains of other orientations; the Ymax domains increase in size with increasing strain. In addition, strain markers show that strain is highly localized within the Ymax domains, indicating geometrical softening of up to an order of magnitude in effective viscosity.

Hydrolytic Weakening of Quartz and Other Silicates*

Rocks at high pressure and temperature become weak when exposed to an aqueous environment. Four different weakening processes have been found: (1) Increase in pore pressure reduces the effective confining pressure, thus negating the strengthening effect of confining pressure (Terzaghi). (2) Penetration of water into the intergranular boundaries reduces the cohesive strength. This is believed to have occurred in the dehydration weakening found in gypsum (Heard & Rubey) and in serpentinite (Raleigh & Paterson). (3) Water promotes recrystallization, greatly reducing the strength at low strain-rates at temperatures above the critical temperature for recrystallization. (4) Water permeates most silicate crystals so far tested and causes hydrolytic weakening of the component crystals of rocks. The most revealing experiments on hydrolytic weakening have been those on single crystals of synthetic quartz with varying water content (Griggs & Blacic). The water content inferred from 3 micron infra-red absorption varies from 0·0015 to 0·13 wt% (100–9000 H/106 Si) in the nine crystals tested. All crystals became weak at a critical temperature dependent on the water content, varying from 380°C at 0·13% to 1070 °C at 0·0015%. The weakening process is thermally activated, is reversible, and is rate dependent. The mechanism of deformation is intracrystalline glide. MLaren has shown by transmission electron microscopy that deformed weakened synthetic quartz contains dislocation densities similar to those found in strong dry quartz deformed in the ductile regime. Annealing of water-weakened quartz removes most of the dislocations and causes the formation of bubbles. These are believed to be water bubbles formed by the reaction Si(OH)4→ SiO2+2H2O, the water migrating through the lattice. The Frank-Griggs hypothesis of hydrolytic weakening is that easy slip occurs only when Si-O-Si bridges adjacent to a dislocation are hydrolyzed by the migration of water. No Si-O bonds need be broken, for dislocation motion can occur by hydrogen bond exchange. All the evidence in hand suggests that hydrolytic weakening is general in silicates containing very small amounts of water. This phenomenon is expected to be important in the mantle, leading to a rate-dependent strength.

Reaction rim growth in the system MgO-Al2O3-SiO2 under uniaxial stress

We synthesize reaction rims between thermodynamically incompatible phases in the system MgO-Al2O3-SiO2 applying uniaxial load using a creep apparatus. Synthesis experiments are done in the MgO-SiO2 and in the MgO-Al2O3 subsystems at temperatures ranging from 1150 to 1350 °C imposing vertical stresses of 1.2 to 29 MPa at ambient pressure and under a constant flow of dry argon. Single crystals of synthetic and natural quartz and forsterite, synthetic periclase and synthetic corundum polycrystals are used as starting materials. We produce enstatite rims at forsterite-quartz contacts, enstatite-forsterite double rims at periclase-quartz contacts and spinel rims at periclase-corundum contacts. We find that rim growth under the “dry” conditions of our experiments is sluggish compared to what has been found previously in nominally “dry” piston cylinder experiments. We further observe that the nature of starting material, synthetic or natural, has a major influence on rim growth rates, where natural samples are more reactive than synthetic ones. At a given temperature the effect of stress variation is larger than what is anticipated from the modification of the thermodynamic driving force for reaction due to the storage of elastic strain energy in the reactant phases. We speculate that this may be due to modification of the physical properties of the polycrystals that constitute the reaction rims or by deformation under the imposed load. In our experiments rim growth is very sluggish at forsterite-quartz interfaces. Rim growth is more rapid at periclase-quartz contacts. The spinel rims that are produced at periclase-corundum interfaces show parabolic growth indicating that reaction rim growth is essentially diffusion controlled. From the analysis of time series done in the MgO-Al2O3 subsystem we derive effective diffusivities for the Al2O3 and the MgO components in a spinel polycrystal as \({\rm D}_{MgO} = 1.4 \pm 0.2 \cdot 10^{-15}\) m2/s and \({\rm D}_{Al_2O_3} = 3.7 \pm 0.6 \cdot 10^{-16}\) m2/s for T = 1350 °C and a vertical stress of 2.9 MPa.

Characterization of the E1′ center in quartz: Role of aluminum hole centers and oxygen vacancies

The growth of E1′ centers in a variety of natural and synthetic quartz crystals has been investigated by employing the electron spin resonance technique. It has been reported that the growth of E1′ centers, formed by irradiation and subsequent annealing at 300 °C for 15 min, scale with the concentration of the aluminum hole center, [AlO4]0, till a limit. Later, the E1′ centers show saturation even when the [AlO4]0-center continues to grow. For quartz with low efficiency of the formation of [AlO4]0-center or irradiated with low accumulated doses, the intensity of E1′ center was small where not all oxygen vacancies are converted to the E1′ center. Thus, besides the availability of a number of oxygen vacancy sites, the number of holes released from the [AlO4]0-center plays an important role in the formation of E1′ centers in quartz.

Characterization of unswept and swept quartz crystals for space applications

Unswept and vacuum-swept synthetic quartz crystals were investigated in order to determine the mechanisms responsible for the radiation sensitivity of this material. Results were obtained by means of infrared (IR) spectroscopy, dielectric relaxation spectroscopy (DRS), and thermoluminescence (TL). First, the effect of vacuum sweeping was clearly demonstrated in IR absorption by a significant decrease in the amount of hydroxyl ions and in DRS by the disappearance of the dielectric loss peak arising from the relaxation of alkali ions. Second, it was shown that swept quartz is less sensitive to irradiation than the unswept crystal. A sharp decrease in the TL sensitivity of the electrolyzed material was observed in the energy range corresponding to the recombination of alkaline-electronic defects. DRS results indicated that the dielectric signal is shifted toward a lower energy range for both types of crystals, suggesting that the irradiation greatly facilitates the relaxation of alkaline species by creating low energy hosting sites. However, this shift is drastically less pronounced in the swept quartz because relaxing species are more stable in this material. Third, a correlation was established in TL between trapped charge carriers at point defects in quartz and the frequency variation in quartz oscillators, which is a very promising result for space applications.

Effect of fast neutrons on structural rearrangement in crystalline quartz

IR spectroscopy has been used to study the effect of reactor radiation on the structural state of different specimens of synthetic quartz crystals. The patterns have been established for modification of the spectral characteristics of the bending vibrations of the crystal lattice as a function of the orientation of the crystals and the fast neutron fluence. It is hypothesized that the identified features of radiation-induced modification of the parameters of the bending modes for the different quartz specimens are due mainly to structural rearrangement occurring in the crystals.