Journal of Crystal Growth最新文献

{"title":"Optimizing single crystal diamond mosaic growth: A study on seed thickness variation and pre-growth treatment","authors":"Kai Li,&nbsp;Jun Zhang,&nbsp;Peicheng Mo,&nbsp;Jiarong Chen,&nbsp;Xiaoyi Pan,&nbsp;Chao Chen","doi":"10.1016/j.jcrysgro.2024.127953","DOIUrl":"10.1016/j.jcrysgro.2024.127953","url":null,"abstract":"<div><div>The limitations on the size of single-crystal diamond applications still need to be addressed for practical use. This study systematically investigates the impact of variations in seed crystal thickness and pre-growth treatments on step bonding, defect formation, and stress distribution in the mosaic growth of single-crystal diamond films. The findings suggest that variations in seed crystal thickness within 50 μm result in a smooth mosaic junction and high crystal quality, while a 100 μm variation results in noticeable defects and stress concentrations, hindering adequate bonding. Pre-growth treatment improves crystal quality by reducing polycrystalline formations and stress concentrations. Optical microscopy and Raman mapping confirm that pre-growth treated mosaic regions exhibit smooth steps and seamless bonding, with FWHM values between 3 and 5 cm⁻¹, consistent with the quality of non-mosaic growth regions.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127953"},"PeriodicalIF":1.7,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535710","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":"Eutectic mixtures of nevirapine: Phase diagrams, solid-state characterization, and dissolution studies","authors":"Rogeria Nunes Costa ,&nbsp;Nathan Kevin Carvalho ,&nbsp;Julian Ticona Chambi ,&nbsp;Marcelo H.C. Chaves ,&nbsp;Helvécio Vinícius Antunes Rocha ,&nbsp;Ana Maria do Espirito Santo ,&nbsp;Silvia Lucia Cuffini","doi":"10.1016/j.jcrysgro.2024.127954","DOIUrl":"10.1016/j.jcrysgro.2024.127954","url":null,"abstract":"<div><div>Solid-state modifications can improve drug performance. Studies have shown that multicomponent crystals, such as cocrystals and eutectic compositions, have successfully improved the performance of certain drugs, including their solubility. Nevirapine (NEV) is an antiretroviral drug with low aqueous solubility, impacting its bioavailability. This work aimed to study different nevirapine/co-former solid eutectic systems, define their phase diagrams and evaluate their dissolution properties. Caffeine (CAF), Theobromine (TEOB), and Theophylline (THEO) were chosen as co-formers due to their functional groups that can interact with NEV. Aiming to determine both temperature and eutectic composition, phase and Tamman diagrams were obtained using the differential scanning calorimetry (DSC) analysis of the mixtures indifferent NEV-co-former compositions (%w/w). Powder X-ray diffraction (PXRD) and DSC were used to characterize the eutectic materials. To assess the influence of eutectic systems on dissolution properties, we determined the powder dissolution profiles and intrinsic dissolution rates of anhydrous NEV and eutectic systems NEV-CAF and NEV-THEO using different dissolution media (pH 1.2 and pH 6.8). The eutectic compositions were calculated through the phase diagrams, interpolating the curves obtained by linear regression. Thus, the eutectic composition of the NEV-CAF system was determined to be 36.55 % NEV and eutectic temperature at 201.1 °C, while in the NEV-THEO system, the eutectic was obtained in a composition of 71.04 % NEV and eutectic temperature at 217.8 °C. Tamman diagrams were generated using the enthalpy values obtained from the DSC curves, and eutectic compositions were calculated using linear regression. The analysis revealed a eutectic composition of 36.51 % of NEV for the NEV-CAF system, and a eutectic composition of 70.94 % of NEV for the NEV-THEO system. It was not possible to determine the eutectic mass fraction of NEV-TEOB. A comparison of dissolution profiles and intrinsic dissolution rates in different dissolution media showed a significant improvement in the NEV dissolution rate in both eutectic systems. In an acidic medium, NEV dissolved 16 times faster in the NEV-CAF sample and 4 times faster in the NEV-THEO sample compared to pure anhydrous NEV. In a neutral medium, the dissolution profile of NEV was even more favorable in the same eutectic systems, showing that the increase in dissolution is relevant in a wide range of pH. In addition, the intrinsic dissolution rate in the two eutectic systems was higher than that of anhydrous NEV in all employed dissolution mediums. These eutectic systems improve the dissolution rate compared to pure NEV, offering the potential for enhancing the dissolution of poorly water-soluble drugs in the future.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127954"},"PeriodicalIF":1.7,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535707","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":"Ultraviolet optical properties of CaSrF2 crystal grown by the cone die Czochralski method","authors":"Yugo Akabe ,&nbsp;Kotaro Enomoto ,&nbsp;Keito Shinohara ,&nbsp;Marilou Raduban ,&nbsp;Toshihiko Shimizu ,&nbsp;Nobuhiko Sarukura ,&nbsp;Rui Okumura ,&nbsp;Ryosuke Kodama ,&nbsp;Kazuya Takahashi ,&nbsp;Toru Kawamata ,&nbsp;Kazumasa Sugiyama ,&nbsp;Tsuguo Fukuda","doi":"10.1016/j.jcrysgro.2024.127949","DOIUrl":"10.1016/j.jcrysgro.2024.127949","url":null,"abstract":"<div><div>Fluoride crystals with extremely wide band gaps are ideal optical materials in the UV wavelength range. Large 4-inch diameter calcium strontium fluoride (Ca_0.582Sr_0.418F₂) single crystal was grown using the Czochralski method with a Cone-shape Die (CD-CZ). The refractive index and relative transmittance of the crystal was evaluated by cutting it into a triangular prism and polished. The direct measurement of the refractive index and relative transmittance was done by using a spectrograph to image the refraction of light as it passes through a dual prism set-up consisting of a SQ prism as reference and either CaF₂ or Ca_0.582Sr_0.418F₂ as the material under evaluation. Characterization results showed that Ca_0.582Sr_0.418F₂ has excellent refractive index dispersion and transmittance in the UV region, confirming the applicability of the dual prism with spectrograph setup to measurements of the refractive index and relative transmittance in the UV region.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127949"},"PeriodicalIF":1.7,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535708","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":"The impact of cooling rate on the structure and properties of VGF-InP single crystals","authors":"Xuefeng Zhu ,&nbsp;Hua Wei ,&nbsp;Guoyong Huang ,&nbsp;Weiquan Deng","doi":"10.1016/j.jcrysgro.2024.127946","DOIUrl":"10.1016/j.jcrysgro.2024.127946","url":null,"abstract":"<div><div>InP is a III-V compound semiconductor with a zinc-blende crystal structure, widely used in optical communications, high-frequency millimeter-wave devices, optoelectronic integrated circuits, and solar cells. During the growth of VGF-InP single crystals, defects such as twinning, dislocations, and polycrystals are prone to occur. Experimental research on the cooling rate, an important control condition during the growth process, was conducted. By analyzing a large amount of discrete cooling data from the premium InP production and using spherical fitting algorithms for numerical analysis, the optimal cooling curve was obtained. Forward and reverse experimental verification results show that by adjusting the cooling rate at each growth stage, the recurrence of twinning and dislocations was successfully improved. Increasing the cooling rate during the shouldering process helps suppress intrinsic twinning but tends to increase dislocation density during the equal diameter stage process, leading to dislocation proliferation. Therefore, while increasing the cooling rate during shouldering, it is necessary to appropriately reduce the cooling rate during the equal diameter stage process to effectively suppress dislocation proliferation. By precisely controlling the temperature gradient and cooling rate inside the furnace, the thermal field conditions during the crystal growth process can be optimized, significantly improving the quality of InP single crystals.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127946"},"PeriodicalIF":1.7,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552963","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":"Visual detection of thermal microvariation characteristics of transparent layer of quartz crucible","authors":"Qian Zhao ,&nbsp;Zheng-Li Miao","doi":"10.1016/j.jcrysgro.2024.127936","DOIUrl":"10.1016/j.jcrysgro.2024.127936","url":null,"abstract":"<div><div>Aiming at detecting and locating bubbles in transparent layer of quartz crucible during the growth of monocrystalline silicon, an improved YOLOv5s model algorithm is proposed in this paper to achieve efficient and accurate crucible bubble detection. Optimize the anchor box through the K-means algorithm to adapt to the bubble dataset before and after the use of the crucible. Utilize the FasterNet backbone network to extract contextual information, enhancing target detection effectiveness. Additionally, the ECA attention mechanism is added to enhance information exchange and improve the accuracy of small target detection. Experimental results show that the improved algorithm performs significantly in bubble detection. For bubble detection before and after use, mAP increased by 2.1 % and 3.29 %, respectively. As usage time increases, the size, shape, and distribution of bubbles in the transparent layer of the quartz crucible change significantly, directly affecting the crucible’s effectiveness. Regular monitoring and evaluation of crucible bubble changes are crucial for maintaining stability and safety in the production process. Further research could explore how these findings can optimize crucible design and usage, improving performance and longevity.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127936"},"PeriodicalIF":1.7,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535711","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":"Flux growth of Cs1-xRbxBF3 (B = Ca, Sr) crystals by the micro-pulling-down method","authors":"V. Vaněček ,&nbsp;T. Horiai ,&nbsp;M. Yoshino ,&nbsp;A. Yamaji ,&nbsp;A. Yoshikawa ,&nbsp;M. Nikl","doi":"10.1016/j.jcrysgro.2024.127919","DOIUrl":"10.1016/j.jcrysgro.2024.127919","url":null,"abstract":"<div><div>The possibility of growing Cs_1-xRb_xBF₃ (B = Ca, Sr) crystals by micro-pulling-down was investigated due to their potential for application in ultrafast scintillation detectors. A LiF flux was applied to lower the melting point and therefore suppress evaporation of CsF from the melt. Suitable growth conditions were obtained through careful choice of the hot zone elements. A crucible with minimal nozzle length improved mass transport and an afterheater with four windows provided a steep temperature gradient. Inclusion and crack-free crystals of Cs_1-xRb_xCaF₃ (x = 0, 0.1, 0.25, 0.5, 0.75, 0.9, and 1) and CsCa_1-xSr_xF₃ (x = 0, 0.1, and 0.25) were grown under optimized conditions. Despite the hygroscopic nature of the heavy alkali metal fluorides, all the grown crystals are non-hygroscopic which significantly improves their application potential. Growth of CsCa_1-xSr_xF₃ crystals with higher Sr concentration was complicated by the low solubility of SrF₂ in the LiF-CsF melt and the hygroscopic nature of the CsSrF₃. The formation of solid solution in the Cs_1-xRb_xCaF₃ and CsCa_1-xSr_xF₃ systems was investigated through the dependence of lattice parameters on nominal composition.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127919"},"PeriodicalIF":1.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535700","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":"Biogenic synthesis of porous CuO nanoparticles: Synergistic effects in photocatalytic dye degradation and electrochemical energy storage applications","authors":"Sajeena Beevi Sharafudheen ,&nbsp;C. Vijayakumar ,&nbsp;R. Rajakrishnan ,&nbsp;Ahmed Alfarhan ,&nbsp;Selvaraj Arokiyaraj ,&nbsp;M.R. Bindhu","doi":"10.1016/j.jcrysgro.2024.127917","DOIUrl":"10.1016/j.jcrysgro.2024.127917","url":null,"abstract":"<div><div>This study explores the biogenic synthesis of CuO nanoparticles functionalized with <em>Solanum nigrum</em>, using <em>Acalypha indica</em> leaf extract as a reducing agent. The biogenically synthesized CuO nanoparticles were comprehensively characterized by various analytical techniques, involves X-ray diffraction analysis (XRD), BET surface area analysis (BET), energy-dispersive X-ray spectroscopy (EDAX), X-ray photoelectron spectroscopy (XPS), UV–Visible spectral analysis (UV), Fourier transform infrared spectroscopy (FTIR), fluorescence spectroscopy, electrochemical analysis, and linear sweep voltammetry studies. The XRD analysis revealed end centered monoclinic phase with a 10 nm average crystalline size. BET analysis showed a mesoporous structure with a surface area of 11.54 m²/g. XPS and EDAX confirmed the presence of Cu²⁺ and O²⁻ ions. SEM and TEM images indicated spherical, and porous nanostructures. UV–Visible spectroscopy identified an active optical range of 508–518 nm (2.40–2.45 eV), suggesting potential photocatalytic activity. The photocatalytic degradation efficiencies of Methylene blue (98.8 %) and Rhodamine B (95 %) were achieved after 100 min of irradiation. Antimicrobial tests demonstrated effectiveness against <em>Staphylococcus aureus</em>, <em>E. coli</em>, <em>Shigella flexneri</em>, and <em>Candida tropicalis</em>. The nanoparticles exhibited notable cytotoxicity against colorectal cancer cells with IC₅₀ values of 58.66 μg/ml. Additionally, a symmetric supercapacitor electrode using these nanoparticles achieved a specific capacitance of 375 Fg⁻¹ at the current density of 1 Ag⁻¹. This research underscores the versatile applications of biogenic CuO nanoparticles in photocatalysis, antimicrobial treatments, cancer therapy, and energy storage.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127917"},"PeriodicalIF":1.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535566","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":"Development of nano-porous Au thin film at room temperature via ion irradiation in a-Ge/Au bilayer system followed by chemical etching of Ge","authors":"G. Maity ,&nbsp;Geetika Patel ,&nbsp;S. Ojha ,&nbsp;S. Dubey ,&nbsp;Shiv P. Patel ,&nbsp;D. Kanjilal","doi":"10.1016/j.jcrysgro.2024.127951","DOIUrl":"10.1016/j.jcrysgro.2024.127951","url":null,"abstract":"<div><div>The development of nano-porous gold (NPG) via room temperature ion irradiation has been presented in detail. The bilayer thin films of <em>a</em>-Ge/<em>c</em>-Au have been irradiated by 100 MeV Ni ions with the fluence of 5 × 10¹³ ions cm⁻² at room temperature. NPG is obtained by selectively etching Ge off from the Au matrix by dipping the Ge/Au thin film into 10 % H₂O₂ solution. Diffusion of Ge and Au across the interface under irradiation was confirmed by TRIM simulation and RBS spectra. The SEM image and EDX spectra confirms the formation of NPG with high purity. In addition, the statistical and fractal analysis of AFM image also confirms the formation of NPG. NPG system has been observed to show very good optical properties (low reflectance and high transmittance). The high quality NPG prepared by this method can be useful in the fields like optical sensors, transparent conductive electrodes, anti-reflective coatings, and photo-detector technology.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127951"},"PeriodicalIF":1.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535702","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":"Epilayer thickness effect on the electrical and breakdown characteristics of vertical β-Ga2O3 Schottky barrier diode","authors":"Hyeon-Cheol Kim,&nbsp;V. Janardhanam,&nbsp;Sameer Pokhrel,&nbsp;Chel-Jong Choi","doi":"10.1016/j.jcrysgro.2024.127941","DOIUrl":"10.1016/j.jcrysgro.2024.127941","url":null,"abstract":"<div><div>The current–voltage and breakdown characteristics of Au/Ni/<em>β</em>-Ga₂O₃ Schottky barrier diodes were investigated as a function of <em>β</em>-Ga₂O₃ epilayer thickness in the range of 6–19 μm. The X-ray rocking curves indicated that the full-width half-maximum is reduced with increasing epilayer thickness, implying an improvement in the crystallinity of <em>β</em>-Ga₂O₃ epilayer. The barrier heights of the field-plated <em>β</em>-Ga₂O₃ Schottky barrier diode with epitaxial layer thickness of 6, 12, and 19 μm were obtained as 1.01, 1.03, and 1.04 eV, with the ideality factor values being 1.21, 1.19, and 1.46, respectively. The higher ideality factors could be associated with the existence of inhomogeneity at the metal–semiconductor interface. The series resistance of the Schottky diode obtained increased with increasing epilayer thickness. The Schottky diode fabricated on 19 μm thick epitaxial layer exhibited a higher breakdown voltage of 490 V. The increase in epilayer thickness led to the widening of depletion region, resulting in lower electric field over a larger distance. This could be a main cause of the enhancement of the breakdown voltage characteristics of <em>β</em>-Ga₂O₃ Schottky barrier diode.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127941"},"PeriodicalIF":1.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535698","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":"Electrical properties of GaAsN/GaAs-superlattice films with different N distributions fabricated by atomic layer epitaxy","authors":"Masahiro Kawano,&nbsp;Tomohiro Haraguchi,&nbsp;Hidetoshi Suzuki","doi":"10.1016/j.jcrysgro.2024.127915","DOIUrl":"10.1016/j.jcrysgro.2024.127915","url":null,"abstract":"<div><div>The effects of nitrogen (N) distribution on the electrical properties of GaAsN films were evaluated by intentionally changing the N distribution using atomic layer epitaxy (ALE) and post-annealing. The N distribution was controlled in the growth direction by growing superlattice (SL) thin films repeatedly growing 1 GaAsN layer and 0, 3, and 5 layers of GaAs by ALE. These films were referred to as (1:0), (1:3), and (1:5), respectively. To change the N distribution in the same thin film, N atoms were diffused by post-annealing. Changes in N distribution were evaluated by X-ray diffraction as changes in GaAsN superstructure. N atoms diffused from GaAsN layers to the adjacent layers in (1:3) films annealed above 750 °C, while they remained stable in those of (1:5) films annealed at temperatures up to 850 °C. The carrier mobility of both films increased monotonically with the annealing temperature. The concentration of ionized scattering centers decreased significantly in films annealed at 650 °C (independent of their N distributions) owing to the elimination of donor-type defects by annealing. Contrarily, the concentrations of N-induced scattering centers in (1:5) films annealed below 900 °C were similar, while those in (1:3) films annealed above 750 °C decreased significantly, in agreement with the N-atom diffusion behavior of GaAsN layers. Thus, N-distribution homogenization can be related to the reduction of N-induced scattering centers.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"649 ","pages":"Article 127915"},"PeriodicalIF":1.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535705","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}