Journal of Crystal Growth最新文献

{"title":"MOCVD/MOVPE epitaxy of group III-V nitride with atomistic Prospective & cost Effectiveness","authors":"P.K. Saxena,&nbsp;P. Srivastava,&nbsp;Anshika Srivastava","doi":"10.1016/j.jcrysgro.2024.127975","DOIUrl":"10.1016/j.jcrysgro.2024.127975","url":null,"abstract":"<div><div>The present study deals with the comparison between two procedures of AlN epitaxy: the Si (111) surface without and with a predose of TMAl. The variation in growth temperature is examined in the samples of both procedures. The use of the pulsed atomic-layer epitaxy (PALE) technique has also been demonstrated successfully to justify the experimental evidence. It was found that PALE is one of the most promising techniques to address the issues associated with the perplexing and controversial question of the initial nucleation process—TMAl or NH₃—first, with the capability to overcome the parasitic gas phase chemical kinetics. The reproduction of the MOCVD/MOVPE experimental growth processes pertaining to AlN buffer layer growth on Si (111) substrate is done through simulation. The work also reviews the previously reported modeling approaches of MOCVD reactor, geometry dependent gas phase chemical kinetics and surface diffusion processes involved in growing films. Synergistic use of different aspects to model an entire film’s growth is carried out within the framework of the TNL-EpiGrow simulator software. Additionally, the simulation results have been matched with the experimental results, and good agreement has been achieved among them, indicating the reliability of the simulations. The TNL-EpiGrow simulator helps in better understanding the MOCVD/MOVPE growth mechanism at atomistic scale and to achieve the optimum growth conditions of group III-V nitrides, thus, helps in reduction of the epitaxy experimentation cost. The simulation studies of different AlN MOCVD growth processes provide valuable and deeper insight, which is generally not available. The simulation studies used MOCVD AIXTRON 200/4 RF-S horizontal flow reactor geometry architecture in all the cases. The major issue of gas phase parasitic reactions, the impact of variations in temperature, and the V/III ratio on the crystal quality of the film has been examined in details. The pulsed atomic-layer epitaxy (PALE) technique implemented in the TNL-EpiGrow simulator was exploited to examine the improvement in the crystal quality. The TNL-Chemical Kinetics utility package is exploited to simulate gas and surface phase chemical reactions. The adsorption, hopping, and desorption mechanism rates are computed using kinetic Monte Carlo (kMC) algorithms implemented in the TNL-EpiGrow simulator to reproduce the real MOCVD reactor based deposition experiments.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"650 ","pages":"Article 127975"},"PeriodicalIF":1.7,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pre-planting amorphous carbon films based on Ir composite substrates for diamond nucleation","authors":"Junfeng Li ,&nbsp;Bing Zhou ,&nbsp;D.G. Piliptsou ,&nbsp;Hui Sun ,&nbsp;Yanxia Wu ,&nbsp;Hongjun Hei ,&nbsp;Jie Gao ,&nbsp;Shengwang Yu","doi":"10.1016/j.jcrysgro.2024.127945","DOIUrl":"10.1016/j.jcrysgro.2024.127945","url":null,"abstract":"<div><div>A tunable locally ordered amorphous carbon layer was pre-implanted on the iridium (Ir) composite substrate using a multi-excitation source plasma coating system. The nucleation interface was mainly studied by scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The results show that by designing and modulating the content and ordering of sp²/sp³ hybridized carbon bonds in the amorphous carbon on the surface of Ir thin films, an overall ordered diamond nucleation layer was obtained. When the pulse frequency of the carbon source was regulated to 9 Hz, the (100) diamond grains were uniformly aligned without the appearance of twins after 4 h of growth, and the nucleation density was 7.5 × 10⁹ cm⁻², which was subsequently expected to obtain single-crystal diamond by grain boundary annihilation. Based on the Ir-amorphous carbon pre-growth layer, it can accelerate the dissolution-precipitation process of carbon ions into the Ir film to form a supersaturated solid solution during the bias nucleation, and increase the nucleation sites, which is of great significance for improving the nucleation density of large-size single-crystal diamond heterogeneous epitaxy.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127945"},"PeriodicalIF":1.7,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fokker-Planck equation for the crystal-size probability density in progressive nucleation and growth with application to lognormal, Gaussian and gamma distributions","authors":"M. Tomellini ,&nbsp;M. De Angelis","doi":"10.1016/j.jcrysgro.2024.127970","DOIUrl":"10.1016/j.jcrysgro.2024.127970","url":null,"abstract":"<div><div>The Fokker Planck (FP) equation for the probability density function (PDF) of crystal size in phase transformations ruled by progressive nucleation and growth, has been derived. Crystals are grouped in sub-sets, we refer to as <span><math><mi>τ</mi></math></span>-crystals, where <span><math><mi>τ</mi></math></span> is the birth time of the set. It is shown that the size PDF is the superposition of the PDF of the crystal sub-sets (<span><math><mi>τ</mi></math></span>-PDFs), with weight given by the nucleation rate. The growth and diffusion coefficients entering the FP equations are estimated as a function of both <span><math><mi>τ</mi></math></span>-PDFs and nucleation rate. The functional form of these coefficients is studied for solutions of the FP equation for <span><math><mi>τ</mi></math></span>-crystals given by the lognormal, Gaussian and gamma distributions. For the first two distributions, the effect of fluctuations, nucleation rate and growth rate, on the shape of the distribution has been investigated. It is shown that for an exponential decay of the fluctuation term, the shape of the PDF is mainly governed by both the time constant for nucleation and the strength of the fluctuation. It is found that <span><math><mi>τ</mi></math></span>-PDFs given by the one-parameter gamma distributions are suitable to deal with KJMA (Kolmogorov Johnson Mehl Avrami) compliant phase transformations, where the fluctuation term is proportional to crystal size. The connection between the FP equation for the size PDF and the evolution equation for the density of crystal populations is also discussed.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"650 ","pages":"Article 127970"},"PeriodicalIF":1.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishment of Multi-Physics coupling model and analysis on thermal stress and crack risk in directional growth of TiAl alloys under electromagnetic confinement","authors":"Jiaxin Li,&nbsp;Jun Shen,&nbsp;Shaokai Zheng,&nbsp;Jiajun Zhao,&nbsp;Wei Wang,&nbsp;Xudong Wang,&nbsp;Zengdi Li,&nbsp;Xiaoyu Gao","doi":"10.1016/j.jcrysgro.2024.127969","DOIUrl":"10.1016/j.jcrysgro.2024.127969","url":null,"abstract":"<div><div>The electromagnetic confinement directional solidification (EMCDS) technique is an optimal method for preparing large-size and non-contamination directional TiAl alloy crystals. Despite its advantages, the high temperature gradient inherent to this process induces thermal stress within the ingot, which increases the risk of cracking. To address this challenge, an innovative Integrated Multi-Physics Coupling Model was established to map and study the thermal stress field during EMCDS in this study. It synchronized the computation of the electromagnetic field, temperature field, solute field, flow field, and stress field during the crystal growth of TiAl alloy, and its high accuracy was proved by the micro-indentation experiment. Our analysis reveals that transverse temperature differences are crucial in inducing thermal stresses, and identifies that hot cracks and cold cracks are prone to occur respectively at the area of radial <span><math><mrow><mfrac><mn>2</mn><mn>3</mn></mfrac><mi>R</mi></mrow></math></span> along the sample (X = <span><math><mrow><mfrac><mn>2</mn><mn>3</mn></mfrac><mi>R</mi></mrow></math></span>) and on the sample surface, which aligns with experimental observations impressively. This model can more accurately and efficiently optimize the process parameters of the EMCDS process to avoid cracks and promote its industrial application.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127969"},"PeriodicalIF":1.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationship between temperature gradient and growth rate during CZ silicon crystal growth","authors":"Shin-ichi Nishizawa","doi":"10.1016/j.jcrysgro.2024.127942","DOIUrl":"10.1016/j.jcrysgro.2024.127942","url":null,"abstract":"<div><div>Temperature distribution in the growing crystal is the most important parameter that determines the grown-in-defects, growth rate, etc. There is a discussion either higher growth rate leads to larger thermal gradient or smaller thermal gradient. In this study, in order to make clear the reason of this discrepancy, the effects of growth rate on the shape of melt/crystal interface, and temperature distribution in growing crystal were investigated by numerical modeling. Firstly, as increasing the growth rate, the shape of melt/crystal interface becomes more concave. And temperature gradient along center axis on growing crystal increases as increasing the growth rate. On the other hand, temperature gradient along surface of growing crystal decreases as increasing the growth rate. To obtain higher growth rate, heat transfer should be enhanced. Along the center axis, heat transfer in vertical direction by heat conduction is dominant. Then concave interface shape and larger thermal gradient along center axis were obtained. In the periphery of grown crystal near the triple points, because of concave interface shape, heat transfer in radial direction, and radiative heat transfer from growing crystal become more important than heat transfer in vertical direction. Then smaller thermal gradient along the growing crystal surface was obtained. This surface temperature profile agrees well with Abe’s measurement results. It is cleared that higher growth rate leads to the higher heat transfer, and melt/crystal interface shape, and temperature distribution in growing crystal are determined by the balance of growth rate and heat transfer between heat conduction in vertical direction and heat conduction in radial direction combined with radiation heat transfer from crystal surface.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127942"},"PeriodicalIF":1.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diffracting crystals of an intrinsically disordered protein (IDP) AtPP16-1 grown in 1.3 V cm−1 DC field","authors":"Noorul Huda,&nbsp;Halavath Ramesh,&nbsp;Abani K. Bhuyan","doi":"10.1016/j.jcrysgro.2024.127959","DOIUrl":"10.1016/j.jcrysgro.2024.127959","url":null,"abstract":"<div><div>DC electric field as weak as ∼1.3 V cm⁻¹ induces crystal nucleation in very dilute protein solutions lacking precipitant. The basis of such growth is the microscopic model of interaction of protein dipoles with the Stark field, leading to glass-like amorphous aggregation and reconfiguration of the aggregates for crystal nucleation. This modest approach is very different from an earlier and rather ‘aggressive’ one in which electric field of ∼1 kV or orders of magnitude in excess is used to influence charge migration in a highly concentrated protein solution having precipitant confined to the crystallization drop. As an application of the precipitant-lacking ultralow protein method, the present work seeks the assistance of internally supplied 1.3 V cm⁻¹ DC field to crystallize an intrinsically disordered protein (IDP) called <em>At</em>PP16-1 in a 0.017 mg mL⁻¹ solution. Crystallization is allowed in cuvette cells of spectrometers with online electric field, enabling measurement of real time changes in spectral features. The average crystal size increases with the time of passage of the electric field, from ∼0.042 at 10 min to 0.165 µm at the end of 300 min. The cubic crystals diffract electron and X-ray. Electron diffraction spot indexing yields lattice spacing <em>d_hkl</em> ∼ 2.85 Å, consistent with 2.88 Å found from powder X-ray diffraction analysis. This level of lattice spacing will correspond to moderately resolved crystal structure of the IDP.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127959"},"PeriodicalIF":1.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the effect of the flow rate of coolant on the kinetics of carbon dioxide hydrate growth using sigmoidal growth model","authors":"Shaghayegh Jahangiri,&nbsp;Fashad Varaminian","doi":"10.1016/j.jcrysgro.2024.127960","DOIUrl":"10.1016/j.jcrysgro.2024.127960","url":null,"abstract":"<div><div>Relaxation time plays a crucial role in studying reaction kinetics and other processes. This study addresses the importance of relaxation time and suggests methods to minimize it. In this article, we adjust the relaxation time by extracting heat from the hydrate formation process through variations in the flow rate of the cooling fluid. It has been demonstrated that heat transfer plays a dominant role in this process. The kinetics of carbon dioxide hydrate growth were evaluated by increasing the flow rate of cooling fluid using modified sigmoidal growth curve equations, including Logistics and Gompertz. It was conducted a nonlinear least-squares regression analysis to fit sigmoidal functions to the cumulative formation curves of hydrate generated from gas uptake in the static reactor over time. The percentage of error between A_real and A_model shows that the Gompertz model with Q = 14.59 Lit/min at T = 276 K and Q = 20.25 Lit/min at T = 277 K is the best model for predicting the maximum consumption capacity of CO₂. The results also showed that increasing the cooling fluid’s flow rate reduces relaxation time at any temperature. Moreover, increasing the flow rate of the cooling fluid decreased the average relaxation time by 2 % to 60 % at T = 276 K and by 7 % to 22 % at T = 277 K compared to the lowest investigated flow rate. Additionally, reducing the experimental temperature while keeping the flow rate of the cooling fluid constant led to a reduction in the relaxation time.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127960"},"PeriodicalIF":1.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of continuous stirring tank reactor for controllable synthesis of Cu7S4 nanocrystals","authors":"Zengmin Tang ,&nbsp;Meng Chen ,&nbsp;Yukun Tang ,&nbsp;Jingjing Du ,&nbsp;Lijian Xu","doi":"10.1016/j.jcrysgro.2024.127967","DOIUrl":"10.1016/j.jcrysgro.2024.127967","url":null,"abstract":"<div><div>As a typical model for a chemical reactor in industry, the continuous stirring tank reactor has been widely used in waste-water treatment, industrial catalysis, and biological fermentation as well as great application prospects in the synthesis of nanomaterials. In this report, a convenient lab-scale continuous stirring tank reactor was assembled and utilized to synthesize Cu₇S₄ nanocrystals by injecting cupric bromide and sulfur solution in the presence of ascorbic acid and polyethyleneimine at 60 °C. The morphology control of Cu₇S₄ nanocrystals was accomplished by simply adjusting the agitation speed. Cu₇S₄ nanofibers with an average diameter of 48 ± 4.42 nm and a length of several micrometers were obtained at 80 rpm. Cu₇S₄ nanoplates with a thickness of 89 ± 13.56 nm and a plane size of 103 ± 16.47 nm were synthesized at 90 rpm, and the size of the nanoplates was regulated by continuously increasing the agitation speed from 90 rpm to 1000 rpm. Furthermore, the influences of two additional conditions (the mean residence time and the concentration of the feed solution) on the morphology of Cu₇S₄ nanocrystals, were also investigated. Therefore, these results could facilitate the understanding of the behaviors of CSTR in the synthesis of Cu₇S₄ nanocrystals and could also provide an important reference for the continuous synthesis of other nanoparticles.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127967"},"PeriodicalIF":1.7,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SAT solver-driven approach for validating local electron counting rule","authors":"Tetsuji Kuboyama ,&nbsp;Akira Kusaba","doi":"10.1016/j.jcrysgro.2024.127927","DOIUrl":"10.1016/j.jcrysgro.2024.127927","url":null,"abstract":"<div><div>Determining large, complex surface structures is essential for understanding and modeling crystal growth. For semiconductor surfaces, the electron counting (EC) rule is known to be useful for predicting surface stability. In this study, a scheme is proposed to automatically determine if a sampled surface structure locally satisfies the EC rule using a Boolean Satisfiability Problem (SAT) solver. This automatic determination is demonstrated on the GaN(0001)-(6 × 6) surface system with H and Ga adsorption as an example. The scheme is also applicable to the automatic generation of surface structures that are expected to be relatively stable, and is expected to accelerate the study of large and complex surface structures of various semiconductor materials.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"650 ","pages":"Article 127927"},"PeriodicalIF":1.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of hydrothermal PPKTP and its spontaneous parametric down-conversion characteristics","authors":"X.D. Song ,&nbsp;X.L. He ,&nbsp;H.Y. Song ,&nbsp;W.D. Zhao ,&nbsp;J.F. Tong ,&nbsp;W.Y. Wu ,&nbsp;H.T. Zhou ,&nbsp;J.L. Wang ,&nbsp;Y.B. Zuo ,&nbsp;C.L. Zhang","doi":"10.1016/j.jcrysgro.2024.127968","DOIUrl":"10.1016/j.jcrysgro.2024.127968","url":null,"abstract":"<div><div>High-voltage electric field polarization, selective corrosion, current monitoring, and other methods are used to develop hydrothermal PPKTP. It is found that the reversal domain nucleation of hydrothermal-grown KTP crystals has four kinds of microscopic morphology, namely, strip shape, spindle shape, bullet shape and irregular shape, in the process of high voltage electric field polarization. Compared with the leakage current in the process of polarization of flux-grown KTP crystals, the hydrothermal-grown KTP crystals only exist when the applied electric field is much larger than the coercive field. The leakage current can be suppressed by multiple loading of short pulses, and the PPKTP with a poled period of 10 μm and 46 μm were fabricated, respectively. Subsequently, based on the fabricated PPKTP, the SPDC characteristics are studied. To the PPKTP with a poled period of 10 μm, the quantum entanglement source whose brightness exceeds 2.1 kHz @ 810 nm is prepared by the SPDC technique. Otherwise, the PPKTP with a poled period of 46 μm is used for SPDC, and the brightness of entangled photon pairs in channel 1 and channel 2 are 3.21 kHz @ 1560 nm and 5.31 kHz @ 1560 nm, respectively.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"650 ","pages":"Article 127968"},"PeriodicalIF":1.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}