Decrease In Resonant Frequency Research Articles

On the displacement control performance of base-isolated structures incorporating nonlinear negative stiffness device

Low-frequency dominant far-field harmonic-like long period ground motions (FGMs) excitations have the potential to amplify the seismic response of base-isolated structures (BIS) and may result in isolator displacements exceeding their maximum limits. The application of negative stiffness devices (NSD) in isolated structures primarily focuses on SDOF systems, which fails to capture the displacement response of the superstructure on the isolation story. To address this issue, this study proposes the application of NSD to a 2DOF system in a BIS, with root mean square value as the metric for displacement transmissibility. Firstly, the displacement transmissibility of base-isolated structures with negative stiffness devices (BIS-NSD) and BIS is derived using the triple-harmonic balance (T-HB) method and the single-harmonic balance (S-HB) method, respectively. Subsequently, the applicability of the T-HB method and the S-HB method in obtaining analytical solution for the displacement transmissibility of BIS-NSD and BIS is revealed and validated through numerical solution. Parameters are selected based on fixed-point theorem for comparative analysis of the displacement and acceleration transmissibility between BIS-NSD and BIS. Finally, a comparative analysis between BIS-NSD and BIS under FGMs confirms the application advantages of NSD. The results indicate that compared to BIS, BIS-NSD significantly reduces the displacement transmissibility of the superstructure and the isolation story in the low-frequency range. As the primary resonance frequency decreases, NSD widens the vibration bandwidth of BIS. BIS-NSD effectively mitigates the increase in displacement caused by low-frequency ground motions. The acceleration transmissibility demonstrates that, without sacrificing the acceleration of the superstructure, it effectively controls the displacement of the isolation story.

Analytical Study of Nonlinear Flexural Vibration of a Beam with Geometric, Material and Combined Nonlinearities

This article explores the nonlinear vibration of beams with different types of nonlinearities. The beam vibration was modeled using Hamilton’s principle, and the equation of motion was solved using method of multiple time scales. Three models were developed assuming (a) geometric nonlinearity, (b) material nonlinearity and (c) combined geometric and material nonlinearity. The material nonlinearity also included both third and fourth nonlinear elasticity terms. The frequency response equation of these models were further evaluated quantitatively and qualitatively. The models capture the hardening effect, i.e., increase in resonant frequency as a function of forcing amplitude for geometric nonlinearity, and the softening effect, i.e., decrease in resonant frequency for material nonlinearity. The model is applied on the first three bending modes of the cantilever beam. The effect of the fourth-order material nonlinearity was smaller compared to the third-order term in the first mode, whereas it is significantly larger in second and third mode. The combined nonlinearity models shows a discontinuous frequency shift, which was resolved by utilizing a set of transition assumptions. This results in a smooth transition between the material and geometric zones in amplitude. These parametric models allow us to fine tune the nonlinear response of the system by changing the physical properties such as geometry, linear and nonlinear elastic properties.

Nonlinear model for assessing seismic resilience in nuclear fuel assemblies

Seismic events may lead to vibrations of fuel assemblies in the nuclear reactor cores, thus the dynamic analysis of such vibration of fuel assemblies is essential for the safety design of nuclear reactor plant. In this paper, by considering the friction between fuel pins, we proposed a nonlinear mechanical model for both static and dynamic analysis of fuel assemblies for pressurized water reactor (PWR). The proposed model used a two-beam structure with frictional units to mimic friction and possible contacts in the pin bundle during the static and dynamic loading in the air. By using this approach, we could characterize not only the hysteresis loop during the static bending test (the static slingshot experiment), but also the decrease of resonance frequency with increase of seismic load. Further, maximum contact forces during the seismic test are compared with experiment at various impact locations, and the predictions closely match the experimental findings, affirming the scientific validity and accuracy of the proposed model. The proposed model can be further used to analyzing seismic behavior of the entire reactor core structure, providing valuable insights for assessing reactor structural safety and predictive hazard assessments.

Impacts of Electrode Resistance on Resonance Characteristics of Film Bulk Acoustic Resonators

In the actual manufacturing process of film bulk acoustic resonators (FBAR), metal leads are necessary to complete the electrical topological connection. However, the electrode resistance will significantly influence the characteristics of the resonator. In this paper, the influence of electrode resistance on resonance characteristics of FBAR is analyzed. To be specific, how different electrode resistances affect the quality factor, impedance value, and electromechanical coupling factor of the FBAR series-parallel resonance frequencies is studied by incorporating the electrode resistances into an overall equivalent electromechanical model (i.e., the Mason model) and the COMSOL finite element simulation method. The results show that the increase of electrode resistance will result in the decrease of the series resonant frequency, the impedance value increases significantly and the quality factor decreases significantly at series resonant, while the parallel resonant frequency does not change, the impedance value slightly increases and the quality factor slightly decreases at parallel resonant, and their electromechanical coupling factor slightly increases.

ВЛАСНІ КОЛИВАННЯ В ПЛАНАРНО-КІРАЛЬНИХ ДВОШАРОВИХ ОБ’ЄКТАХ ПОРОДЖУЮТЬ ШТУЧНУ ОПТИЧНУ АКТИВНІСТЬ

Subject and Purpose. The research focuses on how the resonance frequencies, the Q-factor of resonances, and the polarization plane rotation ability are influenced by the topology of individual components of a planar-chiral double-layer object consisting of a pair of con- jugated irises having rectangular slots and accommodated in a circular waveguide. Methods and Methodology. All the numerical results are obtained by the mode-matching technique (MMT) and the transverse reso- nance method on the basis of our own proprietary MWD-03 software package. Results. By the waveguide example, it has been shown that the internal structure of individual components and dihedral symmetry of the conjugated bilayer allow all the conclusions of the spectral theory (theory of eigen-oscillations) to be carried over to all the objects of the type. On the other hand, these objects behave as symmetric two-port waveguide components with conventionally "symmetric" and "antisymmetric" eigen-oscillations. The mutual coupling of these eigen-oscillations depends on the bilayer parameters. Where the frequen- cies of these eigen-oscillations are close enough, the polarization plane rotation and the transmission bandwidth reach their highest. It has been demonstrated that as a slot number increases, the resonance frequency decreases. The theoretical results have been confirmed by the measurements at the X range of frequencies for pairs of conjugated irises with various numbers of rectangular slots. Conclusions. A pair of conjugated chiral irises can rotate the polarization plane. The iris topology, iris spacing, and the mutual ro- tation angle alter resonance frequencies. The resonance frequencies can be reduced by increasing the rectangular slot length and/or slot number. Even though they have not longitudinal symmetry, such objects have properties of two-port waveguide components. In particular, the phase shift of their reflection and transmission coefficients is modulo 90. Besides, a possibility exists to divide eigen-oscillations into conventionally "symmetric" and "antisymmetric" based on the proximity of their fields to those whose type of symmetry is known before- hand. This makes it possible to approximate the reflection and transmission coefficients through corresponding eigenfrequencies.

Theoretical study on resonance frequencies of vibration modes of Janus-Helmholtz transducer

Janus-Helmholtz transducer has the characteristics of high-power and broadband transmission due to the coupling between the longitudinal resonance of the driver and the liquid cavity resonance of Helmholtz resonator. Traditional view holds that the low frequency resonance peak in the transmitting voltage response curve in water is fluid cavity mode of Helmholtz resonator while the high frequency resonance is the longitudinal mode of Janus transducer. However, in the past few decades, a large number of experimental studies have found that this conclusion is questionable. This work is to distinguish the two resonances in the response curve and the two vibration modes of Janus-Helmholtz transducer. Based on the Janus-Helmholtz transducer prototype reported in the literature, the resonance frequencies of the vibration modes of Janus-Helmholtz transducer are studied theoretically. The structure dimensions and material parameters of the prototype are listed in detail. The test results and simulation results of conductivity are also presented. The longitudinal resonance of the driver is determined by using the equivalent circuit method and finite element analysis. Radiation masses of both Janus transducer and typical longitudinal vibration transducer are also calculated to analyze the phenomenon of the sharp decrease of longitudinal resonance frequency in water. Acoustic modal analysis by using ANSYS software is performed to investigate the resonance frequency of complex Helmholtz resonator in Janus-Helmholtz transducer. Correction length on the vent introduced by external fluid sound radiation is used to obtain the accurate Helmholtz resonance frequency. The sound pressure distribution of Helmholtz resonator obtained through finite element method is investigated, and the correct equivalent formula for solving the Helmholtz resonance frequency is obtained. The results reveal that the first resonance in the response curve is driver resonance while the second one is Helmholtz resonance, which is contrary to the traditional view. The considerable reduction of driver resonance frequency in water is mainly due to the large radiation mass on the four large radiation surfaces of the Janus transducer, which also causes the sharp response of driver resonance. In Janus-Helmholtz transducer, there are two Helmholtz resonators with the same size, instead of only one resonator in the traditional view. The two resonance frequencies solved by the method proposed in this work are in good agreement with the test and simulation results. These conclusions play an important role in correctly understanding the structure and characteristics of Janus-Helmholtz transducer at source, as well as provide technical support for structural optimization and innovation, thus improving the acoustic emission properties of the transducer.

A low-frequency sound insulation metastructure with relatively high ventilation

Noise pollution is growing nowadays and there is always a conflict between ventilation and noise insulation. The advances in acoustic metamaterials provide an effective solution for this conflict. In this paper, we propose a metastructure with protruded necks based on Helmholtz resonance. Sound transmission loss (STL) of 13 dB at low-frequency of 488[Formula: see text]Hz is obtained in experiment with the ventilation of 20%, which is in good agreement with the simulation. It is revealed that introduction of protruded neck can reduce the resonant frequency. Sound absorption is the main mechanism for noise insulation at low frequency. Next, the effects of geometric parameters on sound insulation are discussed. A reduction in cross-sectional area of neck, an increase in neck length, and an increase in ventilation all lead to a decrease in both resonant frequencies and STL amplitudes. Finally, a two-layer structure is constructed by the proposed metastructure with different neck length in each unit. Both the amplitude and frequency range of STL are enlarged. These results exhibit a practical application for ventilated metastructure in sound insulation at low frequency.

Variability in measured resonance frequencies and loss factors of a bolted panel structure

Structural bolted joints are not perfectly contiguous or rigid. Instead, the joint stiffness, mass, and damping depend on many parameters including the joint thickness, number and size of bolts, the bolt preload, and the motion of the jointed region. Also, damping can vary with motion type (stick-slip for friction and impact for joint opening and closing) and amplitude. Finally, all joint dynamic parameters vary from installation to installation. We measured the variability of bolted joint stiffness and damping for four low-order modes of a bolted Aluminum panel structure - two flexural modes and two twisting/torsional modes. While a large portion of the bolted joint literature features a lap joint or an assembly of two beams, there are few studies dealing with flanged connections of plates. Two flanged rectangular panels were bolted together with two cap screws threaded into one of the flanges. Modal resonance frequencies and loss factors were tracked throughout a decaying vibration response induced by hammer impacts on the structure. Measurements were made for three bolt torques and two flange thicknesses, three impact force strengths, and three repeated assemblies (the panel was unbolted and bolted together again). Relative motion at the joint with respect to mode shape determines whether the joint primarily adds stiffness or mass, as well as the amount of added damping. Not surprisingly, reducing bolt preload reduces resonance frequencies. Only minor variability in resonance frequency and loss factor were observed for most conditions, except for cases with low bolt preload. In these cases mild nonlinearity is evident in the response, where resonance frequency decreases and loss factor increases with increasing vibration amplitude. Also, variability of resonance frequencies and loss factors between installations often exceeds that due to variability in preload and vibration amplitude.

Effects of magnetic domain morphology on the magnetic spectrum and high‐frequency core losses of MnZn ferrites

AbstractMnZn ferrites that exhibit low core losses at high frequencies are suitable for the integration and miniaturization of power conversion devices. To obtain low core losses at high frequencies, it is important to understand the underlying mechanism. In this work, MnZn ferrites with various grain sizes were produced by changing the sintering temperature. The relationship between domain morphology, dynamic magnetization behavior, and core losses at high frequencies was carefully investigated. As the average grain size approached the critical size of single‐domain state, the contribution of domain wall displacement to complex permeability decreased, while domain wall resonant frequency improved significantly, resulting in the suppression of residual loss at 3 MHz. As the average grain size increased, the domain morphology changed from a single‐domain state to a multidomain state, which increased the initial permeability and decreased hysteresis loss. However, the number of domain walls increased, causing a significant decrease in the domain wall resonant frequency, and resulting in a sharp increase in residual loss. These results provide valuable insights into reducing high‐frequency core losses in MnZn ferrites by domain engineering.

Effect of anisotropic stiffness degradation on the forced vibration of cylindrical shells

Structural defects are commonly encountered in engineering applications. They can significantly affect not only the structural integrity but also the natural frequencies and vibration responses of cylindrical shells subject to external loading. This study proposes a novel concept of stiffness degradation to analyze the effect of defects on the vibration of shell structures. Specifically, stiffness degradation factors (SDFs) are introduced into the model of a cylindrical shell based on Sanders shell theory, and their influences on the dynamic response of an infinite-length cylindrical shell are evaluated by analyzing vibrations at multiple locations. The results show that vertical vibrations at receiver points located away from the driving point are more susceptible to the stiffness degradation, particularly at higher frequencies. The degradation of flexural stiffness has a greater effect on the vibration of cylindrical shells than the degradation of membrane stiffness, particularly in terms of the resonant frequency decrease. Furthermore, stiffness degradation in the circumferential direction has a greater effect on shell vibration than in the longitudinal direction. By examining the effects of eight SDFs separately, it is revealed that the vibration response of a cylindrical shell is affected by the directions and types of stiffness degradation, the frequency range, and the observation point. Overall, this study provides a general analytical framework for analyzing the vibration response of cylindrical shells including the effect of anisotropic stiffness degradation, which could be applied to composite shell structures with directional fiber orientations and shell structures with various defect modes.

Review of scientific instruments: Evaluation of adulteration in honey using a microwave planar resonator sensor.

A microwave microstrip line resonator sensor is developed as an alternative tool for detecting adulteration in honey. A honey-filled tube is placed at the position with the maximum electric field intensity. When the honey is adulterated, its permittivity is changed, leading to a distinct resonance frequency shift and enabling detection. Compared with the existing microwave sensors, this sensor offers the advantages of low cost, compact size, and easy fabrication. Moreover, quantitative analysis of the adulteration could be achieved. Electromagnetic simulation is performed using a co-simulation with CST and MATLAB. The simulation results reveal that the resonance frequency of the resonator decreases as the added water content increases, following a quadratic polynomial relationship. In the experiments, the results demonstrate a successive decrease in the resonance frequency from the empty tube, honey-filled tube to water-filled tube cases. Furthermore, honey samples with varying water contents (up to 70%) are tested, and the resonance frequency decreases with increasing added water content, which agrees well with the simulation results. In addition, there is a quadratic relationship between the two parameters. Principal component analysis is conducted on the transmission coefficients, and the first principal component decreases with increasing water content. With the addition of the second principal component, the cases of different water contents in honey can be well classified.

Shallow Water Equations on modeling resonant waves evolution in a rough varying-width basin

Wave resonance is known to be extremely damaging to the coastal areas surrounding it, particularly if the wave has tsunami-like features, as it can amplify the height and energy of the wave propagating to the shorelines. The installation of a rough material on the bottom is one of the solutions to protect the coast from resonance. In this study, we examine the resonant wave evolution and its frequency in a triangular or rectangular semi-closed basin using a varying-width Shallow Water Model. The basins are assumed to feature a rough bottom topography as well as an uneven width. The resonant frequencies are obtained analytically and numerically using separation of variables and the finite volume method on a staggered grid, respectively. The computational approach is also used to assess the evolution and properties of resonant waves. The numerical scheme is validated by comparing simulation results to analytical solutions, which show relatively good agreement. Further, it is discovered that a greater friction coefficient induces a higher resonant frequency in both types of basins but results in a lower maximum resonant wave amplitude. It is also found that the resonant frequencies of both types of varying-width basins are greater than those of the prior study’s constant-width basins. However, the effect of the variations in the maximum width of the basin on its resonant frequency is found to be insignificant. Moreover, sensitivity analyses of the basin’s length and maximum basin depth are presented, with the maximum water depth being directly proportional to the maximum wave amplitudes and resonant frequencies of both basins. In contrast, the resonant frequency decreases and the maximum wave amplitude fluctuates as the length of the basin grows.

A nonlinear biodynamic model of seated human body exposed to vertical vibration with sensitivity analysis

The nonlinearity observed in the apparent mass of a seated human body exposed to vertical vibration demonstrates a decrease in resonance frequency as the vibration magnitude increases. However, there is a dearth of appropriate models that accurately capture this nonlinear biodynamic response. Furthermore, the impact of different properties of human body parts on this nonlinearity remains unexplored. This paper presents a model that effectively characterizes the nonlinearity in the apparent mass of a seated human body subjected to vertical vibration.The proposed model incorporates the legs, thighs, pelvis, torso, head, and viscera as key components. Nonlinear springs are employed to simulate the dynamic interactions between the human body and the seat, as well as the connection between the viscera and the pelvis/torso. To validate the model, vertical in-line and fore-and-aft cross-axis apparent masses were measured at the seat pan for 11 subjects without backrest contact, using three different vibration magnitudes (0.4, 0.6, and 1.0 m/s2 r.m.s.).A comprehensive global sensitivity analysis was conducted with the calibrated model to identify the factors that have the greatest influence on the biodynamic response. The results revealed that the stiffness of the soft tissues beneath the thighs, the mass of the thighs, and the mass of the torso were the three most influential parameters affecting the apparent mass. When considering the degree of nonlinearity in the apparent mass, the stiffness of the soft tissues beneath the thighs and the mass of the torso contributed the most.The proposed model holds significant potential for studying the nonlinear biodynamic responses of vehicle drivers and passengers. It provides a valuable tool for gaining insights into the intricate dynamics of human body vibration and can contribute to the development of improved seating systems and enhanced ride comfort in vehicles.

Analysis of HepG2 cell response to a wide concentration range of mitomycin C using a multichannel quartz crystal microbalance system with a microscope

The morphological response of HepG2 cells to mitomycin C was analyzed using a multichannel quartz crystal microbalance system equipped with a home-built movable microscope that enables the simultaneous acquisition of cell images and measurements of eight-channel quartz crystal microbalance. After 24 h of cell seeding, mitomycin C was injected into the culture medium. During the attachment process, the resonant frequency decreased, and the curves fitted well with the first-order lag response. Analysis of the response to mitomycin C revealed that the resonant frequency response curves varied with mitomycin C concentration. When the mitomycin C concentration was <10 μmol L−1, the delay time was observed before the increase in resonant frequency. When the mitomycin C concentration was extremely low, an additional decrease in resonant frequency was observed in the middle of the delay time that fitted well with the cumulative log-normal distribution curve. The resonant frequency response curves after the delay time fitted well with the cumulative log-normal distribution curves. The delay time and mean cumulative log-normal distribution time for the increase in resonant frequency correlated with the mitomycin C concentration; however, the mean time for the additional decrease in the resonant frequency did not show a statistically significant difference as a function of mitomycin C concentration. For mitomycin C concentrations of >20 μmol L−1, the response to the change in resonant frequency was rapid, and the response curves fitted well with the first-order lag response. The first-order lag response indicates that the response occurred simultaneously for all cells. The results showed that the time constant was independent of the tested mitomycin C concentration between 20 and 100 μmol L−1. These results suggested that different cell death processes occurred by mitomycin C. The findings of this study suggest that the system can be used to investigate cell death in adherent cells.

An experimental and theoretical piezoelectric energy harvesting from a simply supported beam with moving mass

The feasibility of harvesting electrical energy from mechanical vibration is demonstrated in the thesis. In the technique, energy is harvested from simply supported beam vibration under a moving mass using a thin piezoelectric material.The structure is represented by a basic beam of length L that is supported at both ends and traversed by a moving mass M travelling at a constant velocity v. The Euler-Bernoulli differential equation describes its behaviour. The dynamic analysis of a beam is performed by using three moving masses of (35.61, 65.81, and 79.41) gr each travelling three uniform speeds of (1.6, 2 and 2.4) m/s. A differential equation of the electromechanical system is obtained by transforming the piezoelectric constitutive equation and solved numerically by MATLAB.The results indicate that the numerical and experimental values for the midpoint deflection of the beam and the piezoelectric voltage are very close.Using the COMSOL programme, the proposed approach is checked by comparing results with data obtained by the finite element method (FEM). An experimental setup was also built and constructed to determine the voltage created by the piezoelectric patch and the beam response as a result of the mass travelling along the beam.The results show that the dynamic deflection, piezoelectric voltage, and piezoelectric energy harvesting all increase as the speed and magnitude of the moving mass increase. The harvesting power vs. load resistance curve begins at zero, increases to a maximum value, and then remains almost constant as the resistance is increased further. The optimal length of the piezoelectric patch was obtained to be 0.63 m. When the length of the beam increases, the resonant frequency decreases, and at the same time the harvested energy increases. However, increasing the beam thickness has the opposite effect; whereas raising the beam width does not affect the resonant frequency but decreases energy harvesting.The most essential point here is the need to have correctly built scale models. They can provide a substantial amount of information at a low cost, accommodate a variety of test settings, and aid in the selection and verification of the most effective analytical model to resolve the actual issue.

Probing Relative Humidity Impact on Biological Protein Bovine Serum Albumin and Bovine Submaxillary Gland Mucin by Using Contact Resonance Atomic Force Microscopy.

In biomaterials, a substantial amount of research has been placed on the mechanical properties of biomolecules and their interactions with body fluids. Bovine serum albumin (BSA) is a widely studied model protein, while bovine submaxillary gland mucin (BSM) is another cow-derived protein frequently employed in research. Films were examined with contact resonance atomic force microscopy (CR-AFM), and the results showed that the mechanical characteristics of the films were affected by the relative humidity. We quantitatively analyze the viscoelasticity of these proteins after they have been subjected to humidity by measuring the resonance frequency and quality factor. The findings indicate that prolonged humidity exposure has a different effect on the mechanical properties of BSA and BSM films. The results show that after exposure to humidity, the resonance peaks of BSA shift to the left, indicating stiffness, while those of BSM shift to the right, indicating hydration. Moreover, BSM's hydration is caused by relative humidity, leading to a constant increase in resonance frequency and material softness. Contrarily, BSA showed a decrease in contact resonance frequency due to ongoing strain-induced deformation, indicating increased material stiffness. The findings have significance for the design and development of biomaterials for a variety of applications, such as the delivery of drugs, the engineering of tissue, and the development of biosensors. Our research demonstrates that CR-AFM has the potential to become a non-invasive and sensitive method that can be used to characterize the mechanical characteristics of biomolecules and their interactions with bodily fluids.

A Study of Dielectric Effects on Resonance Frequency of a Spit Ring Shaped Inclusion

Resonator designs are central to the development of subwavelength unit structures of metasurfaces to create exotic and unique electromagnetic properties by modifying the host structure to tune impinging electromagnetic waves. The act of intentional control of propagating electromagnetic fields are actively being explored in wireless radio environment control for sixth generation (6G) and beyond. In this paper, we study the effect of dielectric properties on electric field distribution and resonance frequency of a circular split ring resonator (SRR). The subwavelength resonator structure is modelled and simulated using High Frequency Structure Simulation (HFSS) software. Rogers RO3003 and RO3210 were used at different thickness to study the field distribution and its effect on resonance frequency of the SSR. The results show a decrease in resonance frequency of 38.41% from RO3002 (lower relative permeability of 3) to RO3210 (higher relative permeability of 10.2). With change in Rogers RO3210 thickness from 1mm to 1.525mm, the resonance frequency has changed from 5.5GHz to 5.2313 GHz. This indicates that the material composition of the substrate and the physical dimension of the SRR unit cell affects the resonance frequency of the structure.&nbsp;&nbsp;&nbsp;&nbsp

A Sensitivity-Enhanced Fiber Optic Fabry-Perot Acoustic Sensor Based on Grooved Diaphragm

A novel fiber optic Fabry-Perot acoustic sensor based on a grooved diaphragm has been proposed, avoiding the decrease of resonant frequency due to the enhanced sensitivity of the sensor based on conventional circular diaphragm. The effect of the structural parameters on sensitivity and resonant frequency is investigated by finite element simulation, and the designed diaphragm is fabricated by a digital light processing 3D printer. Experimental results indicate that the sensor based on the grooved diaphragm has an acoustic pressure sensitivity of 37.44 mV/Pa @2 kHz and a resonant frequency of 2.12 kHz, where the sensitivity is about 2.07 times that of the sensor based on the conventional circular diaphragm and the resonant frequency is almost unchanged. It is shown that the proposed sensor has the advantages of simple fabrication process, high consistency, and excellent applicability for weak acoustic signal detection.

Modelling of coupled magnetoelastic waves in structure containing thin antiferromagnetic films on an elastic substrate

In this work we present a model explaining the properties of magnetoelastic waves propagation in the heterostructure containing an antiferromagnetic layer on a non-magnetic elastic substate. Horizontally polarized shear surface waves (SH-waves) propagating in thin film are Love waves. The dispersion characteristic of magnetoelastic waves in such structure was obtained, and the effect of variation of the thickness of the antiferromagnetic layer and the external magnetic field on the frequency of the magnetoelastic resonance was also studied. It was found that an increase in the magnetic field magnitude leads to the increase in the magnetoelastic resonance frequency, and, on the contrary, with an increase in the thickness of the AFM layer the magnitude of the magnetoelastic resonance frequency decreases. The obtained results can be used to develop devices for generating and processing signals in the GHz and THz frequency ranges.

Управление свойствами магнитоупругих волн в слоистых антиферромагнитных гетероструктурах

In this work we present a model explaining the properties of magnetoelastic waves propagation in the heterostructure containing an antiferromagnetic layer on a non-magnetic elastic substate. The dispersion characteristic of magnetoelastic waves in such structure was obtained, and the effect of variation of the thickness of the antiferromagnetic layer and the external magnetic field on the frequency of the magnetoelastic resonance on the elastic structure was also studied. It was found that an increase in the magnetic field magnitude leads to the increase with pressure of the magnetoelastic resonance frequency, and, on the contrary, with an increase in the thickness of the AFM layer the magnitude of the magnetoelastic resonance frequency decreases. The results obtained can be used to create devices for generating and processing signals in the gigahertz and terahertz frequency ranges.