Density Of Structural Defects Research Articles

In situ construction of Flowerlike bismuth oxide (BiO2-x)/N-rich carbon nitride (C3N5) S-scheme heterojunctions with enhanced structural defects for the efficient photocatalytic removal of tetracycline antibiotic and RhB

Efficient photocatalysts for the simultaneous removal of organic dyes and antibiotics are crucial for sustainable environmental management. In this study, we designed and synthesized a C3N5/BiO2-x S-type heterojunction photocatalyst with structural defects using a hydrothermal method, aimed at degrading both Rhodamine B (RhB) and tetracycline (TC). The degradation kinetic constants for RhB and TC were 0.0809 min−1 and 0.0535 min−1, respectively, showing improvements of 9.52 and 25.48 times over pure C3N5, and 2.90 and 1.49 times over BiO2-x. This enhanced performance is attributed to the unique electron transfer mechanism of the S-scheme heterojunction and the structural defects that facilitate efficient separation of electron-hole (e−-h+) pairs. Free radical trapping experiments indicated that the main reactive oxygen species (ROS) involved are ·O2− and h+. Additionally, electrochemical impedance spectroscopy (EIS) and transient photocurrent response (TPR) measurements confirmed improved separation and transfer of photogenerated e−-h+ pairs in the C3N5/BiO2-x heterojunction. The higher density of structural defects in C3N5/BiO2-x compared to individual BiO2-x counterparts enhances its ability to activate and photo-oxidize TC and degrade RhB. Consequently, C3N5/BiO2-x demonstrates significant potential as a photocatalyst for improving water quality.

Dynamic annealing assisted near-surface structural and bond stabilization in high-temperature low-energy N2+ implanted diamond.

Nitrogen-rich ultra-thin (1-2nm thick) layers in diamond produced by high-temperature nitrogen ion (N2+) implantation at low N2+ energies studied by in situ x-ray photoelectron spectroscopy are reported. Nitrogen bonding at the subsurface region and its thermal stability, as well as structural defects in polycrystalline diamond (PCD) implanted with 200, 500, and 800eV N2+ at room temperature (RT) and 600 °C at an ion dose of 4.5 × 1014 ions/cm2, are investigated. Implantation at RT leads to nitrogen bonding at interstitial and substitutional sites in the diamond lattice, which is associated with the C-N/C=N bond, lower intensity of the C≡N (nitrile-like) component associated with nitrogen bonding with carbon defects, and quaternary nitrogen. The relative composition of these chemical states varies with implantation energy, temperature, and post-implantation annealing temperature. Upon annealing the RT implanted layers above 500-600 °C, the interstitial nitrogen converts to substitutional nitrogen. This process competes with nitrogen desorption. The thermal stability of nitrogen increases with implantation energy. Implantation at 600 °C at 800eV resulted in a significantly lower concentration of nitrile-like bonds and a lower density of structural defects compared to RT implantation at the same energy. These effects are associated with dynamic annealing, which becomes more significant at higher implantation energies. Upon high-temperature implantation, nitrogen mostly populates directly substitutional sites. Nitrogen implantation at low energy and high temperature may be a viable way to nitride diamond surfaces with reduced density of defects where nitrogen is selectively bonded to substitutional sites. Finally, a comparison between nitrogen implantation into PCD and Diamond (100) [Di(100)] surfaces is presented.

Relationship between functionalization and structural defect density of graphite for application in potassium-ion batteries

Potassium-ion batteries (PIBs) have recently gained attention as an alternative to Li-ion batteries (LIBs) because Li and K belong to the same alkali metal group and are replaceable. However, the theoretical capacity of PIBs is hindered by the larger size of potassium ions compared to lithium ions. Generally, the surface treatment of graphite, an anode material in metal-ion batteries, enhances ion diffusivity and improves electrochemical performance. In this study, a straightforward approach is introduced in which graphite is treated with an acid to widen the interlayer spacing and an alkali to create pores. Acid and alkali treatments not only improve ion diffusivity but also control the surface charge of graphite in PIBs. Consequently, acid-treated graphite (AG) displays the highest specific capacity (206.2 mAh g−1 at 0.2 A g−1 after 100 cycles) with good durability. In addition, the trade-off between the physical ion pathway derived from structural defect density and functionalization-induced surface charge improves ion diffusivity.

Roadmap toward Controlled Ion Beam‐Induced Defects in 2D Materials

AbstractUnderstanding the nature, density, and distribution of structural defects is crucial for tailoring the properties of atomically thin two‐dimensional (2D) materials, which is paramount for advances in nanotechnology. Ion irradiation emerges as a promising technique for defect engineering of single‐atom‐thick materials, due to its high controllability, repeatability, and accuracy. The objective is to provide a comprehensive review elucidating the impact of various irradiation parameters, such as ion mass, energy, fluence, and incident angle, on defect formation in 2D materials. However, the presence of the substrate can significantly influence defect yield and the mechanism of formation due to backscattered ions and sputtered substrate atoms. Hence, a thorough comparison of ion beam‐induced defects in both freestanding (suspended) and supported (on a substrate) 2D materials, with a focus on substrate effects is conducted. Moreover, a detailed analysis of characterization techniques suitable for each scenario will be provided. This work not only contributes to advancing the current understanding of defect formation and evolution in 2D materials during ion beam irradiation but also offers insights into selecting specific parameters for this process to create desired defects in these materials. Consequently, it has the potential to facilitate the design of nanoscale devices with tailored functionality.

Contribution of EBSD for the Microstructural Study of Archaeological Iron Alloy Artefacts from the Archaeological Site of Loiola (Biscay, Northern Spain)

Iron palaeometallurgy was carried out on three artefacts, classified as nails and excavated from the archaeological site of Loiola (La Arboleda, Biscay, northern Spain), to investigate Roman manufacturing techniques. Energy Dispersive Spectroscopy (EDS) coupled with Environmental Scanning Electron Microscopy (ESEM) and micro-Raman spectroscopy were used to obtain elemental composition and structural characterization of mineral phases. Metallurgical properties and crystallographic texture were studied by combining microscopic methods such as optical microscopy (OM), Electron Backscatter Diffraction realized in environmental mode (EBSD) and measurements of local Vickers microhardness. The three artefacts had different microstructures, distinguished by a large gradient of carbon content, although important segregations (inclusions) were observed in all of them. Two pearlite-rich artefacts showed a high density of structural defects (geometrically necessary dislocations and large crystallographic orientation gradients in pearlitic ferrite, curved pearlitic cementite) resulting from a high level of plastic deformation that occurred during the manufacturing process. The third artefact consisted of pure ferrite without structural defects. This one was clearly manufactured differently from the two others, so it probably had another functionality.

Acidity-Aided Surface Modification Strategy to Enhance In Situ MnO2 Deposition for High Performance Zn-MnO2 Battery Prototypes.

Zn-MnO2 batteries offer cost-effective, eco-friendly, and efficient solutions for large-scale energy storage applications. However, challenges, like irreversible cathode reactions, prolonged cyclability, and electrolyte stability during high-voltage operations limit their broader application. This study provides insight into the charge-discharge process through in situ deposition of active β-MnO2 nanoflakes on a carbon-based current collector. The study elucidates the effect of pH and electrolyte concentration on chemical conversion reactions with Zn, in particular focus on their impact on the two-electron MnO2/Mn2+ reaction crucial for high voltage operation. The electrolyte, characterized by being relatively lean in Mn2+ and with a targeted low pH, enables extended cycling. This research achieves greater cycling durability by integratinga carbon-based cathode current collector with high density of structural defects in combination with cell architectures suitable for large-scale energy storage. A flooded stack-type Zn-MnO2 battery prototype employing the optimized electrolyte demonstrates a high discharge voltage (≈2V) at a substantial discharge current rate of 10mAcm-2. The battery exhibits an impressive areal capacity of ≈2mAhcm-2, maintaining ≈100% capacity retention over 400cycles. This research establishes a promising practical, and cost-effective cathode-free design for Zn-MnO2 batteries, that minimizes additional processing and assembly costs.

Magnetocaloric effect in Gd-Sc solid solutions

Development of magnetic cooling technology needs effective and suitable solid state refrigerants whose properties meet rigorous functional and market requirements. One of the important issues hindering progress in this field is the lack of a clear understanding of the mechanisms underlying the giant magnetocaloric effect that some materials demonstrate. Considering systems based on one magnetic component seems to be a promising and effective way to unraveling this puzzle. This study is aimed at partially filling this gap by inspecting the magnetic and magnetocaloric properties of a series of GdSc alloys containing up to 25 at.% Sc. It has been established that all obtained alloys form single-phase disordered solid solutions with an hexagonal closed-packed crystal lattice. We found that doping with scandium induces strong distortion effects in the crystal structure due to huge atomic size mismatch. The studied GdSc alloys are ultra-soft ferromagnets with high Curie points. The magnetocaloric response in the alloys is not large in magnitude compared to Gd but the magnetocaloric effect (MCE) extends over a wide temperature interval exceeding 135 K, resulting in the relative cooling power of 930 – 986 J/kg in a magnetic field of 5 T. Such behavior in the MCE is associated with the strongly distorted crystalline structure which provokes complicated magnetic exchange correlations. High density of structural defects in GdSc alloys, induced by large atomic size mismatch, is probably the determining factor in improving the refrigerant capacity.

SCAPS simulation and DFT study of ultra-thin lead-free perovskite solar cells based on RbGeI3

To reduce fossil fuel usage and mitigate greenhouse effects, we have developed an ultra-thin, more stable, and environmentally friendly all-inorganic perovskite solar cell (PSC). We demonstrated the excellent stability of the perovskite absorption layer (RbGeI3) at both micro- and macroscales. The SCAPS software optimized a range of parameters, such as initial structure thickness, bandgap, and defect density, based on continuity equations, Poisson's equation, and transport equations, investigating their impact on device performance. Compared to the pre-optimized state, the optimized fill factor (FF) increased by 26%, and power conversion efficiency (PCE) improved by 34%, while the total thickness was only 700 nm, indicating lower overall stress and increased stability of the device. Additionally, we conducted density functional theory studies on RbGeI3. State density indicated a high hybridization between Ge and I atoms, aiding in forming stable chemical bonds, which was further supported by electron configuration. Charge difference density revealed charge transfer between I and Ge, enhancing the performance of PSCs. Elastic properties demonstrated that RbGeI3 not only exhibited good mechanical stability but also had good toughness, reducing stress during PSCs operation, which is crucial for long-term stability. Our study offers guidance for the development of more stable PSCs.

Rational Regulation of the Defect Density in Platinum Nanocrystals for Highly Efficient Hydrogen Evolution Reaction.

Constructing structural defects is a promising way to enhance the catalytic activity toward the hydrogen evolution reaction (HER). However, the relationship between defect density and HER activity has rarely been discussed. In this study, a series of Pt/WOx nanocrystals are fabricated with controlled morphologies and structural defect densities using a facile one-step wet chemical method. Remarkably, compared with polygonal and star structures, the dendritic Pt/WOx (d-Pt/WOx) exhibited a richer structural defect density, including stepped surfaces and atomic defects. Notably, the d-Pt/WOx catalyst required 4 and 16 mV to reach 10 mA cm-2, and its turnover frequency (TOF) values are 11.6 and 22.8 times higher than that of Pt/C under acidic and alkaline conditions, respectively. In addition, d-Pt/WOx//IrO2 displayed a mass activity of 5158 mA mgPt -1 at 2.0 V in proton exchange membrane water electrolyzers (PEMWEs), which is significantly higher than that of the commercial Pt/C//IrO2 system. Further mechanistic studies suggested that the d-Pt/WOx exhibited reduced number of antibonding bands and the lowest dz2-band center, contributing to hydrogen adsorption and release in acidic solution. The highest dz2-band center of d-Pt/WOx facilitated the adsorption of hydrogen from water molecules and water dissociation in alkaline medium. This work emphasizes the key role of the defect density in improving the HER activity of electrocatalysts.

Epitaxial Lateral Overgrowth of Wafer‐Scale Heteroepitaxial Diamond for Quantum Applications

Wafer‐scale heteroepitaxial diamond thin films demonstrate multiple advantages for a further development of integrated optical and quantum devices based on impurity–vacancy color centers. The main obstacle here is a high structural defect density characteristic for heteroepitaxial epilayers. In this work, technological methods of stress control, NV formation, and defect density reduction in diamond epilayers, which are based on principles of epitaxial lateral overgrowth (ELO) are reported on. Herein, material and quantum properties of NV‐doped diamond thin films obtained by patterned nucleation growth and by ELO of microstructured epilayers, are compared. It is demonstrated that a combination of both methods might have a significant potential for the wafer‐scale production of heteroepitaxial diamond for quantum devices.

Non‐Toxic and Stable Double Perovskite Solar Cells Based on Cs2AgSbX6 Light Harvester: First Principle Calculations‐Aided Theoretical Estimation

AbstractOwing to the low long‐term stability and high toxicity, high‐efficiency perovskite solar cells are yet to be commercialized. Therefore, it is imperative to find a reliable and environmentally benign alternative perovskite light harvester. Herein, the study presents a non‐toxic double perovskite light harvester based on Cs2AgSbX6 (where X = Cl, Br, and I) as a substitute, which can render both high efficiency and long‐term durability. The optoelectronic properties of the Cs2AgSbX6 double perovskite light harvesters are investigated with the Cambridge Serial Total Energy Package (CASTEP) software package that is committed to density functional theory (DFT). The bandgap (indirect) tunability of Cs2AgSbX6 double perovskite light harvesters and associated changes in the density of states (DOS) are explored. The obtained results are further loaded as input to the SCAPS‐1D software package to assess the potential of Cs2AgSbX6 double perovskite solar cells. With the FTO/AZnO/Cs2AgSbX6/MoO3/rear contact device structure, the thickness and bulk defect density of the Cs2AgSbX6 light harvester have superior control over the performance of the double perovskite solar cells. The highest theoretical efficiency of ≈29.9% is estimated for the Cs2AgSbI6 light harvester. Additionally, the effectiveness of several prospective back electrodes is examined.

(Digital Presentation) Internal Friction, Mechanical Spectroscopy in SiO2/Si Wafers

Introduction The electrophysical properties of semiconductor devices significantly depend on the perfection of their structure. It is necessary to control the structure of semiconductor wafer-plates disks in the manufacture of large integrated circuits (LIC). Technique was developed and device was made that allows to obtain the information about structural defects in such disks by attenuating elastic oscillations Q-1 to study the defects density nd and the depth hd of their propagation. Defect annealing leads to change in the shape of internal friction (IF) temperature spectrum Q-1(T) [1]. IF method allows to set the spectrum of structural defects on the analysis of positions of maximums IF, on duration of relaxation time τ and on their deposit in attenuation of elastic vibrations [2]. A non-destructive method for the technological control of the structure defects by measuring internal friction (IF) and elastic modulus E after laser radiation was developed. Experimental procedure Ultrasonic (US) pulse-phase method using USMV-LETI, modernized USMV-KNU and computerized “KERN-4” with frequencies f║ ≈ 1 MHz and f┴ ≈ 0,7 MHz, US invariant-polarization method for determining the effective acoustic μil and elastic constants Cijkl were used [3,4,5]. The measured velocity error was equal to ΔV/V = 0.5÷1,5%. The study of influence of structure defects on damping of vibrations in Si/SiO2 wafer-plates by the diameter of D = 100÷60 mm and by the thickness of hSiO2 ≈ 600 nm, hSi ≈ 470 000 nm, allows to estimate the degree of perfection of crystalline structure. Metallography optical supervision of microstructure by means of the microscope ”LOMO MVT”, atomic-force microscopy (AFM) were used. Results and discussion The quasi-longitudinal US velocity V║[001] = 5870 m/s, elastic modulus E001 = ρV║[001] 2 = 80,28 GPa for SiO2/Si from the oscillogram were determined. Temperature dependence of internal friction Q-1(T) in SiO2/Si wafer-plate p-type, doped with B, KDB-7.5(100) diameter D ≈ 76∙10-3 m, thickness hSi ≈ 460∙103 nm with SiO2 layer thickness hSiO2 ≈ 100 nm after X-ray irradiation with dose Dγ ≈ 102 Gy is showed. Conclusions It was found that as the result of the structural defect annealing IF background Q0 -1 significantly decreases during measuring of IF temperature dependence Q-1(T), which indicates the improvement of SiO2/Si crystal structure.The elastic modulus Е, the shear modulus G, Poisson coefficient μ, IF Q-1 are dependent from SiO2/Si wafer-plate anisotropy.The value of IF background Q-1 0 after temperature T, mechanical treatments describes the changes of the elastic stress σi fields in SiO2/Si wafer-plate.The study of vibrations of disk wafer-plate Si/SiO2 at different harmonic frequencies f0, f2 made it possible to develop the technique for determining the structural defects density nD for semiconductor wafers-substrates.The relationship between IF Q-1 value, the logarithmic decrement of ultrasound damping δ and the dislocations density nD was established for disk-shaped semiconductor wafers-substrates. Acknowledgements This work has been supported by Ministry of Education and Science of Ukraine: Grant of the Ministry of Education and Science of Ukraine for perspective development of a scientific direction "Mathematical sciences and natural sciences" at Taras Shevchenko National University of Kyiv.

Annealing and Doping Effects on Transition Metal Dichalcogenides—Based Devices: A Review

Transition metal dichalcogenides (TMDC) have been considered promising electronic materials in recent years. Annealing and chemical doping are two core processes used in manufacturing electronic devices to modify properties and improve device performance, where annealing enhances crystal quality, reduces defects, and enhances carrier mobility, while chemical doping modifies conductivity and introduces new energy levels within the bandgap. In this study, we investigate the annealing effects of various types of dopants, time, and ambient conditions on the diverse material properties of TMDCs, including crystal structure quality, defect density, carrier mobility, electronic properties, and energy levels within the bandgap.

Surface Chemistry and Specific Surface Area Rule the Efficiency of Gold Nanoparticle Sensitizers in Proton Therapy.

Gold nanoparticles (AuNPs) are currently the most studied radiosensitizers in proton therapy (PT) applicable for the treatment of solid tumors, where they amplify production of reactive oxygen species (ROS). However, it is underexplored how this amplification is correlated with the AuNPs' surface chemistry. To clarify this issue, we fabricated ligand-free AuNPs of different mean diameters by laser ablation in liquids (LAL) and laser fragmentation in liquids (LFL) and irradiated them with clinically relevant proton fields by using water phantoms. ROS generation was monitored by the fluorescent dye 7-OH-coumarin. Our findings reveal an enhancement of ROS production driven by I) increased total particle surface area, II) utilization of ligand-free AuNPs avoiding sodium citrate as a radical quencher ligands, and III) a higher density of structural defects generated by LFL synthesis, indicated by surface charge density. Based on these findings it may be concluded that the surface chemistry is a major and underexplored contributor to ROS generation and sensitizing effects of AuNPs in PT. We further highlight the applicability of AuNPs in vitro in human medulloblastoma cells.

Quasiepitaxial Aluminum Film Nanostructure Optimization for Superconducting Quantum Electronic Devices

In this paper, we develop fabrication technology and study aluminum films intended for superconducting quantum nanoelectronics using AFM, SEM, XRD, HRXRR. Two-temperature-step quasiepitaxial growth of Al on (111) Si substrate provides a preferentially (111)-oriented Al polycrystalline film and reduces outgrowth bumps, peak-to-peak roughness from 70 to 10 nm, and texture coefficient from 3.5 to 1.7, while increasing hardness from 5.4 to 16 GPa. Future progress in superconducting current density, stray capacitance, relaxation time, and noise requires a reduction in structural defect density and surface imperfections, which can be achieved by improving film quality using such quasiepitaxial growth techniques.

Elimination of Domain Boundaries Accelerates Diffusion in MOFs by an Order of Magnitude: Monolithic Metal‐Organic Framework Thin Films Epitaxially Grown on Si(111) Substrates

AbstractMany properties of the emerging class of metal‐organic frameworks (MOFs) depend crucially on defect concentrations, as in case of other solids. In order to provide reference systems with nearly perfect structure and low defect density, a procedure to grow MOFs epitaxially on cm‐sized Si(111) single crystals is developed. The crystalline metal‐organic thin films are in high registry with the substrate's crystal lattice, as demonstrated by synchrotron‐based grazing incidence X‐ray diffraction (GI‐XRD) experiments. The corresponding reduction of MOF defect density is shown to have striking effects on the properties of these porous frameworks. The most pronounced difference concerns mass transport. An increase in the diffusion coefficient of guest molecules by one order of magnitude relative to the same MOF materials with normal defect densities is observed.

In Ukrainian

Investigating the formation of inversion layers (IL) at the Si-SiO2 interface in the manufacturing technology of silicon photodetectors, some dynamics of dislocations after isothermal annealing were revealed, which were absent in samples without inversion. After selective etching of samples with inversion layers, localization of dislocations on the periphery of responsive elements (RE) with accumulation of guard rings (GR) or other elements of n+-type topology outside the RE was observed. This testified to the movement of dislocations on the surface of the Si-SiO2 structures with IL in the direction of the periphery of the crystal during isothermal annealing, which contributed to a significant decrease in the density of structural defects in RE. The described phenomenon can be used to obtain highly doped defect-free silicon structures. Since the presence of dislocations or other violations of the crystal lattice negatively affect the parameters of the products. In the case of using the described phenomenon as a technological method of “cleaning” the surface of silicon structures, there is a need for controlled formation of IL. One of the methods of forming inversion layers can be thermal oxidation in hydrochloric acid vapors according to the principle of dry-wet-dry oxidation (for p-type silicon). Another method that does not require additional materials is the annealing of Si-SiO2 structures at a temperature of 900–950 Celsium degrees in a nitrogen atmosphere for ≥ 240 minutes. Inversion channels, in this case, will be formed due to the redistribution and diffusion of metal impurities in the oxide (which were introduced during previous thermal operations) to the Si-SiO2 interface. In the described case, these structural defects after annealing were localized in the GR, which is also an active element of the phododiodes, as it limits the dark current of the RE, accordingly, the dark current of the GR should also be low. To be able to implement this method, it is necessary to create passive n+-regions on the periphery of the crystals, limited by oxide, which will be the locations of defects after annealing. It can be both separate areas of arbitrary shape and a concentric ring outside the GR. Elements that will be the locations of defects on the periphery can be cut off at the stage of separating the substrates into crystals. After annealing, it is necessary to remove the IL and form an anti-reflective coating by any known method, since the presence of inversion channels contributes to the growth of dark currents. When examining the morphology of defect localization areas after annealing under high-magnification microscopes and with the help of an atomic force microscope, the formation of hexagonal and round defects, which are partial marginal Frank dislocation loops, was observed. The mechanism of dislocation movement described in this article has not been thoroughly studied by us and requires additional research, but it may be related to Cottrell atmospheres and their interaction with IL

Front Cover: Electronic and Charge Transport Properties in Bridged versus Unbridged Nanohoops: Role of the Nanohoop Size (Chem. Eur. J. 41/2023)

The impact of the hoop size on the electronic and charge transport properties of [5]- and [4]-cyclo-N-butyl-2,7-carbazoles is reported. In these examples, a small nanohoop is beneficial for good organization of the molecules into thin films, whereas a large one increases the density of structural defects. More information can be found in the Research Article by C. Poriel and co-workers (DOI: 10.1002/chem.202300934).

Electronic and Charge Transport Properties in Bridged versus Unbridged Nanohoops: Role of the Nanohoop Size.

In the field of π-conjugated nanohoops, the size of the macrocycle has a strong impact on its structural characteristics, which in turn affect its electronic properties. In this work, we report the first experimental investigations linking the size of a nanohoop to its charge transport properties, a key property in organic electronics. We describe the synthesis and study of the first example of a cyclocarbazole possessing five constituting building units, namely [5]-cyclo-N-butyl-2,7-carbazole, [5]C-Bu-Cbz. By comparison with a shorter analogue, [4]-cyclo-N-butyl-2,7-carbazole, [4]C-Bu-Cbz, we detail the photophysical, electrochemical, morphological and charge transport properties, highlighting the key role played by the hoop size. In particular, we show that the saturated field effect mobility of [5]C-Bu-Cbz is four times higher than that of its smaller analogue [4]C-Bu-Cbz (4.22×10-5 vs 1.04×10-5 cm2 V-1 s-1 ). However, the study of the other organic field-effect transistor characteristics (threshold voltage VTH and subthreshold slope SS) suggest that a small nanohoop is beneficial for good organization of the molecules in thin films, whereas a large one increases the density of structural defects, and hence of traps for the charge carriers. The present findings are of interest for the further development of nanohoops in electronics.

(Digital Presentation) Internal Friction, Mechanical Spectroscopy in SiO2/Si Wafers

In this work, after X-ray and electron irradiation, the outcomes of the evaluation dynamic characteristics of interstitial atoms Sij , vacancy V, and O-complexes were evaluated to account for the annealing conditions to derive specific structural defects in the SiO2/Si wafer. A non-destructive method, which allows the determination of the internal friction difference ΔQ-1/Q-1 0 of the elastic vibration structure defect density Nd and the depth of the broken layer hb , is offered for the SiO2/Si wafer. The method was developed, the installation was designed and manufactured for the excitation and registration of damped bending resonant oscillations in a SiO2/Si disc-shaped wafer with a thickness hSiO2 ≈ 100 nm, his = 300÷500×103 nm, and diameter D = 60÷100×10-3 m to measure the structurally sensitive internal friction Q-1 . Measurement of the internal friction background Q-1 0 at harmonic frequencies f0 and f2 allowed us to experimentally determine the nodal lines of the oscillating disks.