Presence Of Structural Defects Research Articles

Hollow CuO/Cu2O octahedrons for selective and stable detection of acetone gas

Acetone (C3H6O) is key member of the volatile organic compound family, which can cause health as well as environmental issues. The identification and sensing of acetone gas are important in many applications such as air quality control and biomarker-based diagnosis. Here, we synthesized hollow CuO/Cu2O octahedrons heterostructure composite through coprecipitation and subsequent heat treatment. The sensor manifested a response of 3.52 to 50 ppm acetone gas at 350 °C. Besides, it showed excellent stability in a 150-day test and excellent repeatability, with a response of 4.15. Also, exhaled gas sensing was carried out using standard method to estimate the acetone concentration in breath. The high sensing capability of the sensor was ascribed to the formation of p-p heterojunctions, the hollow morphology of octahedrons, and the presence of structural defects. The hollow CuO/Cu2O octahedron sensor with good performance may be employed for the detection and monitoring of acetone gas in real situations.

Impact of wrinkle orientation on the nanotribological properties of chemical vapor deposited TMD monolayers using AFM

Structural defects in two-dimensional (2D) materials are ubiquitous and can influence their physical and chemical properties. The presence of structural defects in single atom thick 2D materials such as graphene is detrimental to the tribological properties and is well documented; however, their effects on various other 2D materials such as transition metal dichalcogenides (TMDs) remain largely unexplored. Here, we report the role of wrinkles’ orientation on the nanoscale tribological behavior of the chemical vapor deposited (CVD) tungsten disulfide (WS2) monolayers. Our molecular dynamics (MD) simulations reveal the underlying atomistic mechanism which indicates the presence of wrinkles exhibiting various orientations, and maximum damage occurred when the tip moved at a 45-degree angle to the wrinkle. This underscores the significant influence of wrinkles’ orientation on the wear behavior of WS2 monolayers.

Multilevel magnetoresistance states in La0.7Sr0.3MnO3/BaTiO3/La0.7Sr0.3MnO3 heterostructure grown on MgO

Magnetic tunnel junction (MTJ) is one of the cornerstones of modern information technologies. Bringing MTJ's operation beyond the conventional binary regime, enabled by tunneling magnetoresistance (TMR) effect, is highly promising for prospective memory technologies and neuromorphic hardware development. In this paper, we demonstrate multilevel magnetoresistance states in an all-perovskite-oxide La0.7Sr0.3MnO3 (LSMO)/BaTiO3/LSMO heterostructure grown on MgO substrates. Unlike traditional TMR, we observe four distinct regions of increased magnetoresistance, which result in three magnetic field-induced resistance states in total. We show that the observed phenomenon arises from the low-field magnetoresistance effect, which occurs in the two epitaxial LSMO layers, independently and at different values of the magnetic field. The effect is well simulated by a model based on the presence of structural defects and non-uniform deformations in the LSMO layers, induced by the large lattice mismatch of the LSMO with the MgO substrate. We believe that our findings contribute to the understanding of complex magnetoresistance effects in MTJs and can be taken into consideration for the design of multi-bit memory cells or neuromorphic devices.

Identification of structural defects and their impact on the magnetic memory, static and cyclic strength of VNS9-SH thin sheet trip-steel

Identification of microstructure defects, which are stress concentrators (SC) during the operation of mechanical engineering products, is an important scientific and practical task relevant for manufacturing enterprises. This problem becomes especially urgent and difficult for critical helicopter parts made of sheet TRIP steel VNS9-Sh (23Kh15N5AM3-Sh) and operating under cyclic loads due to the complex microstructure of the steel and small thickness of strips and sheets. To assess the impact of structural defects on the cyclic strength of products made of the steel under study, the specimens were preliminary sorted proceeding from the results of their testing using the method of metal magnetic memory (MMM) and metallographic studies. The MMM method is a structure-sensitive procedure which provides information about the presence of structural defects that arise during the manufacture. Magnetic anomalies in the form of sharp local changes in the intrinsic stray magnetic field (SSMF) (H) and its gradient |ΔH| along the length of the controlled section Δx, were identified on the surface of sheets cut from five different batches. A conventional classification of the identified anomalies was made according to the magnitude of the magnetic field gradient. The specimens of two types were cut in zones of magnetic anomalies and outside them: type 1 — for cyclic tests and type 2 — for metallographic studies. The geometric parameters and field gradient values of magnetic anomalies on specimens of type 1 and type 2 were the same. Metallographic studies in zones of maximum magnetic field gradient on type 2 specimens revealed defects in the form of a strip at the boundary of different structures, which is a structural stress concentrator (SSC) and a source of the inhomogeneity and changes in the magnetic properties. Type 1 specimens with similar magnetic anomalies and Type 1 specimens cut from sheets outside zones of magnetic anomalies were then selected for cyclic testing. Comparative tests for cyclic strength of the specimens with and without specified SSC were carried out. It is shown that the presence of SSC zones in the specimens reduces the number of cycles to failure during cyclic tests by 1 – 2 orders of magnitude compared to the specimens free of SSC. Based on cyclic tensile tests of specimens, a limiting value of the magnetic field gradient was determined that corresponds to the acceptable level of stress concentration on structural defects. This value is recommended for use as a rejection criterion when examining a new tape by the MMM method.

Structural Characterisation of Zeolites Derived from Lithium Extraction: Insights into Channel- and Cage-Type Frameworks

This study investigates the structural and adsorption characteristics of channel- and cage-type zeolites obtained through lithium extraction. Through XRD, FT-IR spectroscopy, and adsorption isotherm analyses, distinct adsorption behaviours of CH4 and CO2 were observed in both zeolite types. Cage-type zeolites exhibited higher adsorption capacities attributed to their structural advantages, highlighting the importance of structural framework selection in determining adsorbent efficacy. The presence of structural defects and an amorphous phase influenced adsorption behaviours, while thermodynamic data underscored the role of adsorbate properties. Kinetics studies revealed the influence of the structural framework on CH4 adsorption and CO2 adsorption kinetics. Analysis of adsorbate–adsorbent interactions demonstrated robust interactions, particularly with LPM16-Y. These findings offer insights into the potential applications of zeolites in gas adsorption processes, emphasising the importance of structural properties and adsorbate characteristics in determining adsorption performance.

Innovative carbon materials from lignocellulosic wastes for electrochemical hydrogen peroxide production: Bridging biomass conversion and material properties

This study aims to assess the electrochemical generation of hydrogen peroxide and hydroxyl radicals (*OH) using carbon cathodes synthesized from three different lignocellulosic residues, Phragmites australis (PA), Cladium mariscus (CM) and Typha domingensis (TD). These vegetal species are commonly used in natural wetlands and phytoremediation processes and can accumulate recalcitrant pollutants within these treatment processes, generating a waste that should be properly managed. To convert these residues into valuable carbon materials, they underwent hydrothermal carbonization (HTC) followed by either chemical activation with KOH or pyrolysis at 1000 ºC. The best results were obtained with chemically activated materials, yielding a maximum H2O2 concentration of 313 mg L−1 with the carbon cathode produced from PA. The specific surface area, oxygenated functional groups and presence of structural defects in carbonous structures, were key parameters related to a good performance as catalysts towards the 2e- Oxygen Reduction Reaction (ORR). It was also demonstrated, in comparison with previous studies, that the presence of heavy metals in the structure of the lignocellulosic residue enhanced the decomposition of H2O2 into *OH. However, in the study of the degradation of a model organic contaminant as methylene blue (MB), it was shown that these *OH were not the main contributors to degradation, as direct H2O2 chemical degradation and adsorption on the carbon materials played the most significant role. Therefore, the outstanding capacity of these lignocellulosic residues as catalysts for the electrogeneration of H2O2 was confirmed, suggesting their potential future application in advanced oxidation processes for water decontamination.

Mechanism and selectivity of MOF-supported Cu single-atom catalysts for preferential CO oxidation

MOFs can achieve atom-precision in the design of single-atom catalysts (SACs). We elucidated the PROX-reaction mechanism on a well-defined Cu-SAC supported by UiO-66 framework using a multitude of experimental methods and detailed DFT computations.

PH-controlled synthesis of ZnO nanoflowers: A correlation study among the optoelectronic properties and improved photodegradation efficiency

ZnO nanoflowers (ZF) were successfully synthesized by a simple pH-controlled co-precipitation technique. Systematic investigations such as X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) were carried out to confirm the structure and morphology of the sample. It has been found that the petals of the nanoflowers are composed of nanorods. The higher Urbach tail energy calculated from the optical absorbance spectrum indicates the presence of structural defects in the sample. The findings confirmed that the photoluminescence (PL), photoconductivity and photocatalytic characteristics of ZnO are inextricably linked to oxygen defects. The presence of oxygen vacancy (Ov) and surface adsorbed oxygen in the sample is confirmed by X-ray Photoelectron Spectroscopy (XPS), PL, Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy. Also, it shows an improved photocatalytic efficiency with Rhodamine B (RhB) dye under UV (100%, 25 min) and visible (98%, 60 min) light irradiation. The higher Förster Resonance Energy Transfer (FRET) between the ZF and RhB dye can have a significant role in the photocatalytic activity of ZnO. Also, the results confirm that the stronger the PL signal, the lesser the photocatalytic activity, because of the rapid recombination of photo-induced electrons and holes. The higher photocatalytic efficiency of ZF results from O-related defects such as Ov and surface adsorbed groups in the sample.

Effect of Vacancy Defects and Hydroxyl on the Adsorption of Glycine on Mg(0001): A First-Principles Study

Glycine (Gly), as one of the fundamental components of biomolecules, plays a crucial role in functional biomolecular coatings. The presence of structural defects and hydroxyl-containing functional groups in magnesium (Mg) materials, which are commonly used as biomedical materials, significantly affects their biocompatibility and corrosion resistance performance. This study computationally investigates the influence of vacancy defects and hydroxyl groups on the adsorption behavior of Gly on Mg(0001) surfaces. All potential adsorption configurations are considered through first-principles calculations. The findings indicate that stronger chemisorption occurs when Gly is positioned at the edge of the groove, where the surface has a vacancy defect concentration of 1/3. Among the four adsorption locations, the fcc-hollow site is determined to be the most favorable adsorption site for hydroxyl. The adsorption energy of Gly on the Mg(0001) surface containing the hydroxyl (−1.11 eV) is 0.05 eV more than that of on the Mg(0001) surface (−1.16 eV). The adsorption energies, electronic properties, charge transfer, and stable configurations are calculated to evaluate the interaction mechanism between Gly and defective surfaces. Calculated results provide a comprehensive understanding of the interaction mechanism of biomolecules on defective Mg surfaces and also indicate the directions for future experimental research.

Prediction of the internal structure of a lithium-ion battery using a single ultrasound wave response

This paper describes a means to predict the internal structure of a lithium-ion battery from the response of an ultrasonic pulse, using a genetic algorithm. Lithium-ion batteries are sealed components and the internal states of the cell such as charge, health, and presence of structural defects are difficult to measure. Ultrasonic inspection of lithium-ion batteries is a recent and growing area of research. Reflected and transmitted ultrasound pulses are proposed as a non-invasive means of gaining insights into the internal structure and changes within the closed body of a cell. However, the multiple layers present in a lithium-ion cell are problematic when attempting to interpret waveforms as many internal reflections superimpose. Attributing specific features of a cell to wave characteristics is challenging.In this work a genetic algorithm has been developed as a means to reverse engineer a single ultrasound wave response to predict the internal layered structure of a lithium-ion battery cell. A first randomised guess at the layered structure is made. A numerical wave propagation model is used to predict the ultrasound waveform associated with that structure. This waveform is then compared with a measured or reference waveform to establish its fitness. The layered structure is generationally mutated until the predicted waveforms converge on the reference signal. As this occurs the predicted layered body reveals insights into the cell structure under inspection.Initially, the algorithm was tested against an idealised model battery and its predicted waveform, giving a model-model verification. Further, experimental ultrasonic reflection signals were captured from small capacity lithium-ion cells. Estimations of layer structure predicted by the model were compared with CT-scans of the cells to assess performance. The genetic algorithm was found to be effective in converging the predicted wave response to the reference signal and creating accurate battery structures. It was shown that only part of the waveform was required to generate accurate predictions, which is helpful in avoiding parts of the signal contaminated by near field transducer effects.It was demonstrated that the genetic algorithm can predict material wave speed to 40–1100 m/s (3–29 %) accuracy when battery layer geometry is provided; and thicknesses to within approximately 0.2–7.5 μm (1–13 %) when material properties are provided. Providing the genetic algorithm with parameter constraints; either the layer topology and/or the material properties, substantially improved predictions to estimate the wave speeds on average to approximately ±50 m/s (3–4 %) and the layer thicknesses ±5 μm (7–8 %).This raises the possibility of the use of this approach to predict state of charge when the battery construction is known, or the presence of internal defects and damage to a known battery material composition.

Effect of structural defects on the physiochemical properties of supportive single-layer graphene in a sliding electrical contact interface under ambient conditions

We investigated the physiochemical properties of single-layer graphene (SLG) with controlled structural defects that were used in sliding electrical contact. Conductive atomic force microscopy (cAFM) probes applied with electric biases were used to rub the SLG surface under ambient conditions. Structural and chemical properties of rubbed SLG were investigated using Raman spectroscopy, photothermal infrared atomic force microscopy (AFM), and X-ray photoelectron spectroscopy. The work function (WF) and conductivity were determined using Kelvin probe force microscopy and cAFM. Adhesive properties were examined using AFM in the force-volume mode. Biases applied to the cAFM probe resulted in the tunneling triboelectric effect (TTE), which modulated the WF of SLG. The formation of water menisci around the cAFM probe–SLG contact will be electrolyzed, leading to the surface oxidation of SLG, which also impacts the WF of SLG. Compared with pristine SLG with minimum defects, more-defective SLG enhanced the TTE and surface functionalization during the rubbing process, substantially affecting the morphological, electronic, chemical, and adhesive properties of rubbed defective SLG. Our results demonstrated that the physiochemical properties of SLG in a sliding contact are considerably affected by the presence of structural defects in SLG, which should be considered when SLG is used for electrode applications.

Structural Reconstruction Strategy Enables CoFe LDHs for High-Capacity NH4 + Storage and Application in High-Energy Density Ammonium-Ion Hybrid Supercapacitors.

Exploration of high-performance aqueous ammonium-ions hybrid supercapacitor has attracted tremendous research attention recently. Herein, structural reconstructed cobalt-iron layered double hydroxides (SR-CoFe LDHs) featuring copious structure defects (i. e., oxygen-vacancies, M-O bonds, MOO- bonds, coexistence of Co2+ /Co3+ and Fe2+ /Fe3+ ) are reported as a high-capacity cathode for NH4 + storage. The resulting SR-CoFe LDHs can deliver a reversible capacity of 167.9 mAh g-1 at 0.5 A g-1 , which is 3.3 folds higher than that of pristine CoFe-LDHs. Ex-situ experimental results and theoretical studies denote that the presence of structural defects in the CoFe-LDHs can lower the NH4 + adsorption energy and induced electron delocalization to enhance the electrical conductivity, rendering the CoFe-LDHs exhibits excellent performance for NH4 + storage. As a proof of concept, ammonium-ion hybrid supercapacitor has been assembled with CoFe-LDHs as the cathode and hierarchical carbon as the anode, which can deliver a large specific capacitance of 238.3 F g-1 , long cycle stability over 10000 cycles, and high energy density of 66.2 Wh kg-1 within a wide working voltage of 2 V. Overall, this work offers some insights into the design of high capacity cathode for aqueous NH4 + storage and also illustrates the construction of aqueous hybrid devices with NH4 + as the charge carrier.

Tuning Catalytic Activity of Ni–Co Nanoparticles Synthesized by Gamma‐Radiolytic Reduction of Acetate Aqueous Solutions

AbstractTransition metal‐based catalysts show great potential to replace Pt‐based material in energy conversion devices thanks to their low cost, reasonable intrinsic activity, thermodynamic stability, and corrosion resistance. The electrochemical performance of such catalysts is sensitive to their composition and structure. Here, it is demonstrated that homogeneous alloy nanoparticles with varying Ni‐to‐Co ratio and controlled structure can be synthesized from aqueous Ni(Co) acetate solutions using a facile γ‐radiolytic reduction method. The obtained samples are found to possess defects that are ordered to form polytypes structures. The concentration of these defects depends on the Ni‐to‐Co ratio, as supported by the results of ab initio calculations. It is found that structural defects may influence the activity of catalysts toward the oxygen evolution reaction, while this effect is less pronounced with respect to the oxygen reduction reaction. At the same time, the activity of Ni–Co catalysts in the hydrogen evolution reaction is affected by formation of NiOH bonds on the surface rather than by the presence of structural defects. This study demonstrates that the composition of NiCo nanoparticles is an essential factor affecting their structure, and both composition and structure can be tuned to optimize electrochemical performance with respect to various catalytic reactions.

Chemical Synthesis of La0.75Sr0.25CrO3 Thin Films for p-Type Transparent Conducting Electrodes.

The imperative need for highly performant and stable p-type transparent electrodes based on abundant metals is stimulating the research on perovskite oxide thin films. Moreover, exploring the preparation of these materials with the use of cost-efficient and scalable solution-based techniques is a promising approach to extract their full potential. Herein, we present the design of a chemical route, based on metal nitrate precursors, for the preparation of pure phase La0.75Sr0.25CrO3 (LSCO) thin films to be used as a p-type transparent conductive electrode. Different solution chemistries have been evaluated to ultimately obtain dense, epitaxial, and almost relaxed LSCO films. Optical characterization of the optimized LSCO films reveals promising high transparency with ∼67% transmittance while room temperature resistivity values are 1.4 Ω·cm. It is suggested that the presence of structural defects, i.e., antiphase boundaries and misfit dislocations, affects the electrical behavior of LSCO films. Monochromated electron energy loss spectroscopy allowed changes in the electronic structure in LSCO films to be determined, revealing the creation of Cr4+ and unoccupied states at the O 2p upon Sr-doping. This work offers a new venue to prepare and further investigate cost-effective functional perovskite oxides with potential to be used as p-type transparent conducting electrodes and be easily integrated in many oxide heterostructures.

Self-Assembled p–n Homojunction in SnS2 Nanosheets for Enhanced Visible Light-Driven Photocatalysis

Defect engineering and hetero-interfacial bending are standard approaches for enhancing carrier separation and increasing visible light absorption in a semiconductor photocatalyst. Here, we demonstrate the evolution of sulfur vacancies (VS) and the self-assembly of a p–n homojunction through prolonged aqueous washing of SnS2 nanosheets. The experimental studies have validated increased hydrophilicity, layer thinning, VS generation, and extended photocarrier lifetime in washed SnS2 nanosheets. Density functional theory has revealed the changes in the local electronic structure of SnS2 in the presence of structural defects. An electrochemical impedance spectroscopy study has shown that VS actuates the self-assembly of a pseudo-p-type SnS layer over n-type SnS2 to generate the p–n homojunction. The p-type carrier densities are increased twice as the number of washings is increased from 3 to 10 times. The photocatalytic efficacy of the SnS2 homojunction is evaluated in the study of the degradation of several water contaminants under white light and monochromatic excitations. The proposed mechanism shows that the built-in electric field at the p–n junction promotes the separation of the photogenerated electrons and holes. Meanwhile, VS traps the electrons and transfers them to the catalytically reactive centers to participate in photocatalysis. Our findings demonstrate that a simple approach that involves prolonged aqueous washing of as-produced SnS2 promotes the formation of VS and the self-assembly of a p–n homojunction in SnS2 nanosheets with improved visible light photocatalytic performances.

Mechanical properties of graphene nanoplatelets containing random structural defects

Graphene nanoplatelets (GNPs) consist of a small number of graphene sheets connected through van der Waals forces and, like graphene, offer exceptional mechanical, thermal and electric properties. In this work, GNPs are considered as potential reinforcements in composites and their equivalent mechanical properties are computed. Similarly to graphene, the mechanical behavior of GNPs is greatly affected by the presence of structural defects and therefore, a parametric investigation is conducted herein. Three types of planar defects are considered: Stone–Wales, single vacancy and double vacancy defects. The examined parameters include the defect type, density, distribution as well as the number of graphene layers. The Molecular Structural Mechanics approach is employed to simulate the lattice of each graphene sheet, where the C–C covalent bonds are modeled by energetically equivalent beam elements. The van der Waals interactions between two carbon atoms belonging to different graphene sheets are modeled using truss elements with mechanical properties based on Lennard-Jones potential. Equivalent properties are computed by employing a homogenization-like procedure and random fields of the stiffness tensor are obtained through the moving window technique. A severe reduction of the stiffness of GNPs is observed for vacancy defects, which also lead to considerable variability. Inplane behavior, which differs greatly from out of plane behavior, is shown to be much more susceptible to the effect of defects.

Synthesis of Ti3AlC2 max phase under vacuum, its structural characterization and using for Ti3C2Tx MXene preparation

The MAX phase (Ti3AlC2) was synthesized by sintering Ti, TiC, Al precursors under vacuum. The effect of temperature on the formation of the Ti3AlC2 phase was studied. The MAX phase with a minimum amount of impurities was obtained under vacuum at 1300 °C. The phase composition, structure, and state of the surface of the MAX phase were investigated. It was found that carbon vacancies are formed in the Ti3AlC2 lattice. Oxidized states of Ti, C, and Al elements are present on the surface of Ti3AlC2 crystallites. Despite the presence of structural defects and oxidized surface states of titanium and aluminum, the synthesized MAX phase was suitable for preparing 2D MXene particles (Ti3C2Tx) and highly concentrated stable colloidal solutions (up to 5 g/L) based on them. Thin MXene films, prepared from such Ti3C2Tx colloidal solution, were characterized by a high electrical conductivity of 3000 S/cm.

Strength and fracture behaviors of ultralong carbon nanotubes with defects

The presence of structural defects can result in large discrepancies between theoretical and experimental values of the strength of CNTs. To reveal the relationship between the strength and defects of CNTs, experiments accompanied with an experiment-based molecular dynamics simulation were conducted in this paper, where defects were introduced using oxygen plasma irradiation and the strength of the defective CNTs was measured by uniaxial tensile experiments. It was found that the strength of CNTs was controlled by the feature length of defects and the introduction of the single adatom, C–C bond breaking, and vacancy defect could decrease the strength by 8.2%, 23.2%, and 18.5%, respectively. Especially, when these defects synergized, the strength of CNTs ranged from 0 to 76.8% of the theoretical strength, which was confirmed by the experiments. Moreover, by defining cracks based on the atomic stress distributions around defects, the fracture of CNTs obeyed the Griffith's brittle fracture criterion and the atomic stress distributions along the crack plane obeyed the classical fracture mechanics theory except for some deviation near the crack tip. This work gives a perspective on reasons for the theory-experiment discrepancies on the strength of CNTs over the years, obtains the quantitative relationship between the size of defects and the strength of CNTs and provides a research paradigm for verifying the validity of fracture mechanics theories at nanoscale. • The adatom, C–C bond breaking, and vacancy defects are introduced to CNT by oxygen plasma irradiation. • The feature length of defects controls the strength of CNTs when these defects synergize. • The fracture of CNTs obeys the Griffith's brittle fracture criterion by regarding defects as cracks. • Atomic stress distributions obeys the classical fracture mechanics theory except for some deviation near the crack tip. • The characteristic length in GES is to separate two atoms from the maximum interaction to the interaction can be ignored.

Novel Materials Based on Nonideal Supercrystal Formed by a Tunnel Connected Array of Microcavities Containing Ensembles of Quantum Dots

Numerical model for a defect-containing lattice of microcavities with embedded ultracold atomic clusters (quantum dots) is developed. It is assumed that certain fractions of quantum dots are absent, which leads to transformation of polariton spectrum of the overall structure. The dispersion relations for polaritonic modes are derived as functions of structure defects concentrations and elastic strain. It is shown that, as a result of elastic strain of the system and presence of structural defects under study, it is possible to achieve necessary changes in its energy structure (and, therefore, optical properties) determined by the rearrangement of the polariton spectrum.

HRTEM and XPS characterizations for probable formation of TiBxNy solid solution during sintering process of TiB2–20SiC–5Si3N4 composite

The microstructural characterization of spark plasma sintered (SPSed) TiB2–20SiC–5Si3N4 composite was investigated precisely by high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). The in-situ phases generated during SPS process were studied using HSC chemistry software; the result shows the development of plausible reaction between Si3N4 and B2O3, forming h-BN. In addition, the formation of in-situ TiN phase and/or TiBxNy solid solution was confirmed by XPS analysis, attributed to the reaction between TiO2 and Si3N4. The intense interfaces were formed due to the coherency between hexagonal structures of TiB2, SiC, and BN phases as detected by HRTEM. Furthermore, weak interfaces were generated because of the formation of amorphous phases in the junctions. The presence of structural defects and distortions was demonstrated in both TiB2 and h-BN by inverse fast Fourier transform patterns, which can be considered as the main channels for the diffusion and transportation of boron atoms into the Si3N4 matrix for the formation of the in-situ h-BN phase.