AT-cut Quartz Crystal Resonator Research Articles

水晶マイクロバランス法を用いた走査型ずれ応力顕微鏡の開発

This paper describes a new scanning probe microscope which is able to measure the shearing stress generated by the interaction between the STM tip and the sample surface under STM controlled. The method of measurement is utilized the quartz crystal microbalance technique. The sample is deposited on the AT-cut quartz crystal resonator surface, and the shearing stress which is generated in the sample causes the resonance frequency shift of the quartz crystal resonator. By detecting this signal, we can obtain the shearing stress distribution. The gold thin films have been observed for the STM surface topography and the distribution of subsurface shearing stress simultaneously. In the experiment, the sensitivity of the shearing stress is as high as 0.12 N/m for a 0.05 Hz frequency shift of the quartz crystal resonance frequency.

Electrochemical intercalation of cations into an amorphous WO3 film and accompanying changes in mass and surface properties

Abstract The electrochemistry of electrodes coated with amorphous WO3 film in propylenc carbonate containing 0.1 M LiClO4, NaClO4, KPF6 or tetraethylammonium (TEA) perchlorate was examined. The surface density of redox-active sites on the WO3 film coated electrode is larger for smaller cations (Li+ > Na+ > K+). The charge transfer rate was also faster for smaller cations. In the KPF6 solution, the solvophilicity of the film surface increased with potential cycling, while no significant changes were observed in the LiClO4 solution and NaClO4 solution. In the LiClO4 solution, an apparent mass increase during cation intercalation, estimated using an AT-cut quartz crystal resonator, was roughly in agreement with the mass number of Li+. However, in the NaClO4 solution, an apparent mass increase was significantly larger than the mass number of Na+; this may be caused by stress generated by intercalation of the massive cation. Electrochemistry was not observed in the TEAClO4 solution. Proton intercalation was not observed in the TEAClO4 solution even in the presence of water (1.5 wt%), but was observed in the presence of CF3COOH (10 mM).

Highly sensitive quartz crystal immunosensors for multisample detection of herbicides

A piezoelectric quartz crystal immunosensor was developed for the multisample detection of herbicides in water. The antibodies against triazine derivatives were deposited onto a polystyrene-coated 9 MHz AT-cut quartz crystal resonator. A competitive immuno-reaction method with a protein-labelled antigen was utilized. The resulting frequency change due to the adsorption of protein-labelled atrazine was measured. The atrazine concentration was detectable in the range 0.001 to 1 ng/ml, and the linear correlation could be obtained from 0.01 to 1 ng/ml of atrazine. Several triazine derivatives were tested and found to be detectable owing to the cross-reactivity of the antibody.

Temperature dependence of the intrinsic mechanical Q of AT-cut quartz crystal resonators

The temperature dependence of Q factor of the thickness shear mode AT-cut quartz crystals is investigated by use of the piezoelectric resonance signal with an inductive pulse detection method. The intrinsic Q of the crystals is over 10 6 at low temperatures and shows much weaker temperature dependence than expected.

Analysis of piezoelectric bulk-acoustic-wave resonators as detectors in viscous conductive liquids

An analytical solution for the resonance condition of a piezoelectric quartz resonator with one surface in contact with a viscous conductive liquid is presented. The characteristic equation that describes the resonance condition and accounts for all interactions including acoustoelectric interactions with ions and dipoles in the solution is obtained in terms of the crystal and liquid parameters. A simple expression for the change in the resonance frequency is obtained. For viscous nonconductive solutions, the frequency change is reduced to a relationship in terms of the liquid density and viscosity. For dilute conductive liquid, the change in frequency is derived in terms of the solution conductivity and dielectric constant. The boundary conditions for the problem are defined with and without the electrical effects of electrodes. Experiments were conducted with various viscous and conductive chemical liquids using a fabricated miniature liquid flow cell containing an AT-cut quartz crystal resonator. The results, which show good agreement with the theory, on the use of quartz crystal resonators as conductivity and/or viscosity sensors are reported.

Theory and application of a quartz resonator as a sensor for viscous liquids

A comprehensive analysis of the interaction between an AT-cut quartz crystal resonator and a viscous fluid is presented. The analysis, which includes peizoelectric effects, assumes a liquid of finite extent and therefore could also be used to study thin film of viscous liquids. A novel continuous flow cell system was designed and fabricated to monitor viscosity using an 11-MHz quartz crystal resonator. Measured data for frequency shifts of aqueous solutions of alcohols and sugars are in excellent agreement with theory.

Quartz resonator as sensor for viscous/conductive liquids

A theoretical and experimental study of an AT-cut quartz crystal resonator as a sensor for viscous conductive liquids has been performed. A novel continuous-flow cell system and an 11 MHz quartz crystal were used for the experiments. Results are presented for aqueous dilute solutions of potassium chloride (KCl) and potassium nitrate (KNO3).

Healing length near the lambda point in liquid helium.

Viscous shear waves have been used to probe the spatial variation and healing of the viscosity and superfluid density near a solid wall in bulk He i, bulk He ii, and in saturated superfluid films with thicknesses from 14 to 24 nm. The shear waves were generated at 20 and 34 MHz with an AT-cut quartz crystal resonator, and the transverse-acoustic impedance of the helium was measured at temperatures T close to the \ensuremath{\lambda} point at ${T}_{\ensuremath{\lambda}}$. In bulk He ii the results confirm a previous measurement of the healing length a(T)=(0.094\ifmmode\pm\else\textpm\fi{}0.002)${\ensuremath{\epsilon}}^{\mathrm{\ensuremath{-}}2/3}$ nm, where \ensuremath{\epsilon}=\ensuremath{\Vert}1-T/${T}_{\ensuremath{\lambda}}$\ensuremath{\Vert}. In bulk He i the measurements suggest that the viscosity exhibits healing above ${T}_{\ensuremath{\lambda}}$ near a solid wall with a similar healing length as in He ii. Healing effects were observed below the superfluid transition temperature in the films and are also described by the same healing length as in the bulk liquid.

Variational analysis of GT‐Cut quartz crystal resonators with the supporting portions at the ends

AbstractIt is well known that a GT cut quartz crystal resonator coupled between two extensional mode vibrations has a cubic curve in frequency‐temperature characteristics as well as an AT cut quartz crystal resonator. This paper studies frequency‐temperature characteristics and electrical characteristics of the GT cut quartz crystal resonator with the supporting portions at both ends of the vibrational portion.First, a secular equation is derived from a vibration analysis of the resonator consisting of the vibrational portion and the supporting portions, by applying the energy method. From this secular equation, a relationship of resonant frequency, frequency temperature coefficients vs. a cut angle, a dimensional ratio and a mass ratio for the GT cut quartz crystal resonator is clarified theoretically. At the same time, from comparison of the calculated values with the experimental values, it is confirmed that they agree very well. Next, electrical characteristics of the quartz crystal resonators manufactured for trial experiments are measured. As a result, it is confirmed that a GT cut quartz crystal resonator with excellent frequency temperature characteristics, low crystal impedance and a high quality factor is realized.

Vibration analysis of flexural–torsional mode tuning fork–type resonators

AbstractIt is well known that a flexuraltorsional quartz crystal resonator which couples a torsional mode vibration to a flexural mode vibration, has a cubic curve in frequency temperature characteristics as well as an AT cut quartz crystal resonator. This paper describes the frequency‐temperature characteristics of a tuning fork‐type quartz crystal resonator which couples the torsional mode vibration to the flexural mode vibration and the estimated results of the various constants for the resonator manufactured for trial experiments. First, a secular equation coupled the torsional mode vibration to the flexural mode vibration is calculated. From the secular equation, frequency‐temperature characteristics for the flexural‐torsional mode tuning fork‐type resonator have been analyzed theoretically, specifically concerning a relationship of the resonant frequency, the frequency‐temperature coefficients vs. thickness, a normalized frequency and a cut angle. Next, by manufacturing tuning fork‐type flexural‐torsional quartz crystal resonators, the calculated values are compared with the experimental values, at the same time, the various constants of the resonators manufactured for trial experiments are estimated. As a result, it is confirmed that tuning fork‐type flexural‐torsional quartz crystal resonators with excellent frequency‐temperature characteristics, low‐crystal impedance, and a high quality factor are realized.

Investigation of the amplitude distribution of AT-cut quartz crystals

The three-dimensional equations of linear piezoelectricity are used to compute the mechanical vibration amplitude distributions, as well as the resonance frequencies of plano-convex circular AT-cut quartz crystal resonators. These computations are compared with vibration amplitude measurements employing a new technique that utilizes the speckle effect. Very good agreement has been found between the measured and the computed vibration amplitude distributions.

Aging characteristic of light-modulation quartz-crystal oscillator with glass-bar-mounted plano-convex AT-cut quartz-crystal plate

A glass-bar-mounted plano-convex AT-cut quartz-crystal resonator (GMPA resonator) is employed in the oscillator to work as a three-port network device. In this case, the light beam is modulated with the dynamic stress of the oscillating quartz-crystal plate and the modulated-light beam is used as a feedback loop of the oscillation. The experimental results for the frequency/temperature characteristic of the oscillator system are presented. About 5 × 10−9 aging rate for a week was realised in the present oscillator.

Erratum: Measurement of thickness-shear-stress distribution of the oscillating planoconvex AT-cut quartz-crystal resonator

Erratum: Measurement of thickness-shear-stress distribution of the oscillating planoconvex AT-cut quartz-crystal resonator

Measurement of thickness-shear-stress distribution of the oscillating plano-convex AT-cut quartz-crystal resonator

The paper compares measured and calculated thickness-shear-stress distributions of a plano-convex AT-cut quartz-crystal resonator oscillating at its fundamental, 3rd overtone and 5th overtone thickness-shear resonant vibration frequencies. The calculated resonant frequencies and the vibration-stress distribution calculated numerically using a finite-element method show good agreement with those obtained experimentally.

An analysis of contoured crystal resonators operating in overtones of coupled thickness shear and thickness twist

A previous treatment of overtone modes in trapped energy resonators is extended to the case of plates with slowly varying thickness. The resulting single scalar equation is applied in the analysis of plano-convex contoured quartz crystal resonators, and a lumped parameter representation of the admittance, which is valid in the vicinity of a resonance, is obtained. The analysis holds for the fundamental and anharmonic overtones of the fundamental and each harmonic overtone thickness mode. The influence of piezoelectric stiffening, electrode mass loading, and electrical shorting is included in the analysis. No adjustable parameters are required in the theory. Although the basic piezoelectric differential equation employed here is quite different from the ones that have been employed in similar applications heretofore, the analysis accounting for the contouring has appeared in the literature. It is shown that calculations based on the analysis agree extremely well with experimental results obtained with contoured AT-cut quartz crystal resonators.

Measurement of thickness-shear-stress distribution of the oscillating plano-convex AT-cut quartz-crystal resonator

The paper compares measured and calculated thickness-shear-stress distributions of a plano-convex AT-cut quartz-crystal resonator oscillating at its fundamental, 3rd overtone and 5th overtone thickness-shear resonant vibration frequencies. The calculated resonant frequencies and the vibration-stress distribution calculated numerically using a finite-element method show good agreement with those obtained experimentally.

Thickness-shear stress distributions of the oscillating planoconvex AT-cut quartz-crystal resonator

Thickness-shear stress distributions of a planoconvex AT-cut quartz-crystal resonator oscillating with the fundamental, 3rd overtone and 5th overtone thickness-shear vibration resonant frequencies are measured by means of a laser-beam modulation method. The measured stress distributions are compared with the stress values computed by the finite element method for a simulation study. The experimental values show good agreement with the computed stress distributions. The absolute value of the measured stress agrees with that in the experiment of Spencer.

Laser interferometric measurement of the vibration displacements of a plano-convex AT-cut quartz crystal resonator

Detailed vibrational displacement distributions of the thickness-shear modes of a plano-convex AT-cut quartz plate have been measured for the first time utilizing a laser interferometric technique. The technique is unique in that simple introduction of a low-frequency phase modulation into one of the laser beams makes measurements essentially free from the environmental mechanical disturbances, and hence relatively simple optical setups may be used for measuring in-plane vibration displacements down to the order of several angstroms.

A Polylithic Filter Channel Bank

The advent of AT-cut quartz crystal resonator filters has made possible the design of high-quality channel translation equipment with reduced cost and size. This paper describes a new channel bank, with built-in carrier generation, employing 8-MHz polylithic crystal filters for sideband selection and singleresonator filters for carrier selection. Integrated and hybrid thick film circuits have been used to provide increased reliability and size reduction The modulation plan, equipment design, and performance are discussed.

Factors influencing the accuracy of a quartz-crystal oscillator as a thickness monitor for thin-film deposition

Results are given on the continuous measuring of the mass thickness of thin metal and dielectric films over a large thickness range by coating experiments with a 4.96 MHz fundamental-mode AT-cut quartz-crystal resonator. The electronic circuit and the construction of a suitable crystal holder with low damping and for reduction of the temperature influence on the quartz frequency is discussed. Also information is given on the mass sensitivity depending on previous mass charges of the quartz crystal obtained in a special arrangement.