Pub Date : 2025-03-20DOI: 10.1016/j.jcrysgro.2025.128157
Sarang R. Daf , Dilip S. Badwaik , Shrikant M. Suryawanshi , Bhupendra T. Kumbhare , Bhaurao R. Balbudhe , Rupesh S. Wandhare
Spinel ferrite nanoparticles (SFNPs), such as Mg0.2Ni0.6Zn0.2Fe2O4, have unique properties that are influenced by their synthesis methods. Different bottom-up approaches, including sol–gel, auto-combustion, hydrothermal, and co-precipitation method were used to prepare these nanoparticles. Structural, morphological, optical and magnetic properties were analysed using techniques like X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). Crystallite sizes measured using Scherrer’s formula were 28.9 nm, 20.2 nm, and 7.5 nm for the respective synthesis methods. FTIR spectra indicated metal–oxygen bond formation, TEM and SEM confirms cubical shaped morphology while VSM analysis revealed the pseudo-single domain nature of the synthesized SFNPs. The observed and estimated parameter strongly suggests that these materials could be used in biomedical and electronic applications.
{"title":"Effects of synthesis methods on the structural and magnetic properties of Mg0.2Ni0.6Zn0.2Fe2O4 spinel ferrite","authors":"Sarang R. Daf , Dilip S. Badwaik , Shrikant M. Suryawanshi , Bhupendra T. Kumbhare , Bhaurao R. Balbudhe , Rupesh S. Wandhare","doi":"10.1016/j.jcrysgro.2025.128157","DOIUrl":"10.1016/j.jcrysgro.2025.128157","url":null,"abstract":"<div><div>Spinel ferrite nanoparticles (SFNPs), such as Mg<sub>0.2</sub>Ni<sub>0.6</sub>Zn<sub>0.2</sub>Fe<sub>2</sub>O<sub>4</sub>, have unique properties that are influenced by their synthesis methods. Different bottom-up approaches, including sol–gel, auto-combustion, hydrothermal, and co-precipitation method were used to prepare these nanoparticles. Structural, morphological, optical and magnetic properties were analysed using techniques like X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). Crystallite sizes measured using Scherrer’s formula were 28.9 nm, 20.2 nm, and 7.5 nm for the respective synthesis methods. FTIR spectra indicated metal–oxygen bond formation, TEM and SEM confirms cubical shaped morphology while VSM analysis revealed the pseudo-single domain nature of the synthesized SFNPs. The observed and estimated parameter strongly suggests that these materials could be used in biomedical and electronic applications.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"660 ","pages":"Article 128157"},"PeriodicalIF":1.7,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715148","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}
Pub Date : 2025-03-18DOI: 10.1016/j.jcrysgro.2025.128154
J. Weng , J. Liu , X.J. Chen , F. Liu , F.J. Cui , J.H. Wang , L.W. Xiong
In this work, the growth environment for the SCDs and the diamond film are improved by refine the arrangement of the substrate holder in our self-developed MPCVD apparatus. The arrangement of the substrate holder is controlled by the △h which is kept less than 3.0 mm. The plasma around the substrate holder is systematically researched with multi-physical simulation and OES. The △h is finally selected at 1.5 mm and 0.5 mm to prepare SCDs and diamond film. Using the arrangement of the substrate holder, the cracks in the SCDs put at the edge of the Mo substrate and the fragmentation of the freestanding diamond film are effective avoided. The results turn out that the uniformity of the plasma can be enhanced by reasonable selecting the △h, and in this way the edge effect of the substrate can be effectively utilized. The obtained results provide a guidance for the scalable production of diamond material.
{"title":"Investigation on the effect of refine adjusting substrate holder on the preparation of diamond","authors":"J. Weng , J. Liu , X.J. Chen , F. Liu , F.J. Cui , J.H. Wang , L.W. Xiong","doi":"10.1016/j.jcrysgro.2025.128154","DOIUrl":"10.1016/j.jcrysgro.2025.128154","url":null,"abstract":"<div><div>In this work, the growth environment for the SCDs and the diamond film are improved by refine the arrangement of the substrate holder in our self-developed MPCVD apparatus. The arrangement of the substrate holder is controlled by the △h which is kept less than 3.0 mm. The plasma around the substrate holder is systematically researched with multi-physical simulation and OES. The △h is finally selected at 1.5 mm and 0.5 mm to prepare SCDs and diamond film. Using the arrangement of the substrate holder, the cracks in the SCDs put at the edge of the Mo substrate and the fragmentation of the freestanding diamond film are effective avoided. The results turn out that the uniformity of the plasma can be enhanced by reasonable selecting the △h, and in this way the edge effect of the substrate can be effectively utilized. The obtained results provide a guidance for the scalable production of diamond material.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"659 ","pages":"Article 128154"},"PeriodicalIF":1.7,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644329","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}
Pub Date : 2025-03-18DOI: 10.1016/j.jcrysgro.2025.128143
Tianyu Wang , Chuan Tang , Qian Wu , Wen Li , Zhen Jia , Yuntao Wu , Mingjun Xia
A crack-free Rb4Li2TiOGe4O12 (RLTG) bulk crystal with dimensions up to 43 × 42 × 27 mm3 was grown by the high-temperature solution method and investigated for luminescence properties under UV and X-ray excitation for the first time. RLTG crystal displays an exceptional bluish-green photoluminescence peaking at 481 nm with a photoluminescence quantum yield 55.81 %. The fluorescence of the RLTG crystal comes from the isolated distorted TiO5 square pyramids. The light yield of RLTG crystal was measured to be 12,000 photons/MeV under steady-state X-ray excitation, surpassing that of the commercial scintillator Bi4Ge3O12 (BGO).
{"title":"Luminescence properties of Rb4Li2TiOGe4O12 single crystal grown by high-temperature solution growth","authors":"Tianyu Wang , Chuan Tang , Qian Wu , Wen Li , Zhen Jia , Yuntao Wu , Mingjun Xia","doi":"10.1016/j.jcrysgro.2025.128143","DOIUrl":"10.1016/j.jcrysgro.2025.128143","url":null,"abstract":"<div><div>A crack-free Rb<sub>4</sub>Li<sub>2</sub>TiOGe<sub>4</sub>O<sub>12</sub> (RLTG) bulk crystal with dimensions up to 43 × 42 × 27 mm<sup>3</sup> was grown by the high-temperature solution method and investigated for luminescence properties under UV and X-ray excitation for the first time. RLTG crystal displays an exceptional bluish-green photoluminescence peaking at 481 nm with a photoluminescence quantum yield 55.81 %. The fluorescence of the RLTG crystal comes from the isolated distorted TiO<sub>5</sub> square pyramids. The light yield of RLTG crystal was measured to be 12,000 photons/MeV under steady-state X-ray excitation, surpassing that of the commercial scintillator Bi<sub>4</sub>Ge<sub>3</sub>O<sub>12</sub> (BGO).</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"659 ","pages":"Article 128143"},"PeriodicalIF":1.7,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684074","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}
We conducted a comprehensive investigation into the optimal architecture of light-emitting devices operating in the 230 nm wavelength band, which were fabricated face-to-face by annealing sputter-deposited AlN templates for electron-beam excitation. The structures and multiple quantum wells were systematically optimized. The present findings revealed that employing AlN as the underlayer and the barrier layers produced significant improvements in surface smoothness and enhanced cathodoluminescence intensity. Moreover, the optimized device was successfully integrated with a graphene-based electron source, facilitating light emission through electron-beam excitation and achieving a power efficiency of 0.16 %. Remarkably, this power efficiency remained stable with increasing injected current from the graphene-based electron source, demonstrating a linear increase in light output without the efficiency droop associated with conventional light-emitting diodes. These results validate the potential of a simplified device structure that eliminates the need for a p-type layer, aiding the development of large-area, high-output light sources within the 230 nm band.
{"title":"230 nm electron-beam excited light source with AlGaN/AlN multiple quantum wells on face-to-face annealed sputter-deposited AlN template","authors":"Ryoya Iwase , Ryota Akaike , Hiroki Yasunaga , Takao Nakamura , Masayoshi Nagao , Katsuhisa Murakami , Hideto Miyake","doi":"10.1016/j.jcrysgro.2025.128142","DOIUrl":"10.1016/j.jcrysgro.2025.128142","url":null,"abstract":"<div><div>We conducted a comprehensive investigation into the optimal architecture of light-emitting devices operating in the 230 nm wavelength band, which were fabricated face-to-face by annealing sputter-deposited AlN templates for electron-beam excitation. The structures and multiple quantum wells were systematically optimized. The present findings revealed that employing AlN as the underlayer and the barrier layers produced significant improvements in surface smoothness and enhanced cathodoluminescence intensity. Moreover, the optimized device was successfully integrated with a graphene-based electron source, facilitating light emission through electron-beam excitation and achieving a power efficiency of 0.16 %. Remarkably, this power efficiency remained stable with increasing injected current from the graphene-based electron source, demonstrating a linear increase in light output without the efficiency droop associated with conventional light-emitting diodes. These results validate the potential of a simplified device structure that eliminates the need for a p-type layer, aiding the development of large-area, high-output light sources within the 230 nm band.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"660 ","pages":"Article 128142"},"PeriodicalIF":1.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679748","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}
Pub Date : 2025-03-14DOI: 10.1016/j.jcrysgro.2025.128140
Abani K. Bhuyan
ATP crystals are grown under bare conditions of DC potential, ionic strength, and solute concentration without a precipitant. A 1.6 V cm−1 DC field supplied internally to aqueous solutions containing as low as 0.003 mg mL−1 ATP in 1 mM phosphate buffer appears sufficient for the growth of orthorhombic crystals. The effect of the electric field (EF) on molecular ionization and monomer → aggregate transition are analyzed by UV–visible and fluorescence spectroscopy. The aggregation process starts in less than an hour after turning the DC field on, and the aggregates appear to nucleate and enter the crystal phase in hours or days. Processes innate to electrochemistry are minimized or do not interfere with the interaction of the EF with the molecular dipole, forcing predominant aggregation in the solution itself. The crystals are imaged and indexed using electron microscopy and powder X-ray diffractogram. A series of experiments in which the amount crystallized as a function of initial concentration of ATP in the 0.003–13 mg mL−1 range was determined yields an indicator isotherm of crystallization at 298 K that shows that the amount of ATP used up to produce the crystalline phase decreases rapidly with the initial concentration used.
{"title":"Crystals grown from precipitant-free ultralow concentrate ATP (adenosine triphosphate) solutions with extremely low DC potential","authors":"Abani K. Bhuyan","doi":"10.1016/j.jcrysgro.2025.128140","DOIUrl":"10.1016/j.jcrysgro.2025.128140","url":null,"abstract":"<div><div>ATP crystals are grown under bare conditions of DC potential, ionic strength, and solute concentration without a precipitant. A 1.6 V cm<sup>−1</sup> DC field supplied internally to aqueous solutions containing as low as 0.003 mg mL<sup>−1</sup> ATP in 1 mM phosphate buffer appears sufficient for the growth of orthorhombic crystals. The effect of the electric field (EF) on molecular ionization and monomer → aggregate transition are analyzed by UV–visible and fluorescence spectroscopy. The aggregation process starts in less than an hour after turning the DC field on, and the aggregates appear to nucleate and enter the crystal phase in hours or days. Processes innate to electrochemistry are minimized or do not interfere with the interaction of the EF with the molecular dipole, forcing predominant aggregation in the solution itself. The crystals are imaged and indexed using electron microscopy and powder X-ray diffractogram. A series of experiments in which the amount crystallized as a function of initial concentration of ATP in the 0.003–13 mg mL<sup>−1</sup> range was determined yields an indicator isotherm of crystallization at 298 K that shows that the amount of ATP used up to produce the crystalline phase decreases rapidly with the initial concentration used.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"659 ","pages":"Article 128140"},"PeriodicalIF":1.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684073","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}
Pub Date : 2025-03-14DOI: 10.1016/j.jcrysgro.2025.128144
Duan Xiaochen , Huang Xuguang , Wang Yulong , Chai Chen , Han Qinghui , Ma Haotian , Bai Guijie
CZ method utilizes a quartz crucible to grow solar-grade monocrystalline silicon. The primary component of the quartz crucible is SiO2, which contributes most of the oxygen and negatively impacts the efficiency of solar cells. CGSim numerical simulation software is employed to analyze the effects of heating power, interfacial stress, melt flow, and silicon-oxygen content at varying heights of the main heater. The results indicate that shortening the main heater can increase power, expand the low-temperature region of the melt, and weaken the melt convection along the sides of the crucible, thereby reducing the precipitated oxygen content (from 7.11 × 10^17 atoms/cm3 to 5.85 × 10^17 atoms/cm3, a reduction of 17.7 %). After the addition of a second heater, the crystal oxygen content is further decreased by 8.7 %, with the minimum oxygen content reaching 5.34 × 10^17 atoms/cm3. According to production data, shortening the main heater and incorporating a second heater can lead to a 24.6 % reduction in oxygen content, demonstrating a significant decrease in oxygen levels.
{"title":"Study on the influence of 36-inch hot field heater structure on the oxygen content of Czochralski monocrystalline silicon","authors":"Duan Xiaochen , Huang Xuguang , Wang Yulong , Chai Chen , Han Qinghui , Ma Haotian , Bai Guijie","doi":"10.1016/j.jcrysgro.2025.128144","DOIUrl":"10.1016/j.jcrysgro.2025.128144","url":null,"abstract":"<div><div>CZ method utilizes a quartz crucible to grow solar-grade monocrystalline silicon. The primary component of the quartz crucible is SiO2, which contributes most of the oxygen and negatively impacts the efficiency of solar cells. CGSim numerical simulation software is employed to analyze the effects of heating power, interfacial stress, melt flow, and silicon-oxygen content at varying heights of the main heater. The results indicate that shortening the main heater can increase power, expand the low-temperature region of the melt, and weaken the melt convection along the sides of the crucible, thereby reducing the precipitated oxygen content (from 7.11 × 10^17 atoms/cm<sup>3</sup> to 5.85 × 10^17 atoms/cm<sup>3</sup>, a reduction of 17.7 %). After the addition of a second heater, the crystal oxygen content is further decreased by 8.7 %, with the minimum oxygen content reaching 5.34 × 10^17 atoms/cm<sup>3</sup>. According to production data, shortening the main heater and incorporating a second heater can lead to a 24.6 % reduction in oxygen content, demonstrating a significant decrease in oxygen levels.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"659 ","pages":"Article 128144"},"PeriodicalIF":1.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644328","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}
Pub Date : 2025-03-13DOI: 10.1016/j.jcrysgro.2025.128141
Song Fu, Qun Ma, Yang Li, Junjie Kang, Meng Liang, Xiaoyan Yi, Junxi Wang, Jinmin Li, Zhiqiang Liu
Electrically insulating GaN epilayers with good crystal quality are essential but challenging for power electronics. Iron (Fe) doping is a valuable method to achieve high resistivity GaN grown by metal–organic chemical vapor deposition (MOCVD). Here, we investigated the impacts of Fe dopants on growth kinetics and electron transition processes in GaN. It is found that the Fe dopants act as surfactants during growth, facilitating the coalescence of GaN and thus effectively limiting the incorporation of oxygen (O) impurities from the substrates into epilayers by 30 times. Meanwhile, the Fe dopants induce a (0/-) transition level, 0.59 eV below the conduction band minimum, which serves as electron traps capturing free electrons and resulting in high resistivity. The relevant mechanism was discussed in detail, and a quantitative model was established, with the consideration of free electron density, donor and Fe concentration, and temperature. Benefit from those, GaN films on patterned sapphire substrates (PSS) with a dislocation density of 1.3 × 108 cm−2, a resistivity up to 7.4 × 109 Ω∙cm, and free of intentional Fe doping at the surface of the epilayer can be achieved. The clarification of Fe dopants in GaN paves the way for future advanced electronic devices and applications.
{"title":"Iron-induced low background impurity and high resistivity GaN films grown by MOCVD on patterned sapphire substrates","authors":"Song Fu, Qun Ma, Yang Li, Junjie Kang, Meng Liang, Xiaoyan Yi, Junxi Wang, Jinmin Li, Zhiqiang Liu","doi":"10.1016/j.jcrysgro.2025.128141","DOIUrl":"10.1016/j.jcrysgro.2025.128141","url":null,"abstract":"<div><div>Electrically insulating GaN epilayers with good crystal quality are essential but challenging for power electronics. Iron (Fe) doping is a valuable method to achieve high resistivity GaN grown by metal–organic chemical vapor deposition (MOCVD). Here, we investigated the impacts of Fe dopants on growth kinetics and electron transition processes in GaN. It is found that the Fe dopants act as surfactants during growth, facilitating the coalescence of GaN and thus effectively limiting the incorporation of oxygen (O) impurities from the substrates into epilayers by 30 times. Meanwhile, the Fe dopants induce a (0/-) transition level, 0.59 eV below the conduction band minimum, which serves as electron traps capturing free electrons and resulting in high resistivity. The relevant mechanism was discussed in detail, and a quantitative model was established, with the consideration of free electron density, donor and Fe concentration, and temperature. Benefit from those, GaN films on patterned sapphire substrates (PSS) with a dislocation density of 1.3 × 10<sup>8</sup> cm<sup>−2</sup>, a resistivity up to 7.4 × 10<sup>9</sup> Ω∙cm, and free of intentional Fe doping at the surface of the epilayer can be achieved. The clarification of Fe dopants in GaN paves the way for future advanced electronic devices and applications.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"659 ","pages":"Article 128141"},"PeriodicalIF":1.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645029","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}
Single crystals of KYbxY1-x(WO4)2 of high optical quality were grown at a rate of about
4.0 mm/day by the modified Czochralski method. The crystals have been grown using the so-called dynamic growth regime. The optimal temperature gradients have been determined at the crystallization front. Thermal expansion coefficients of KYbxY1-x(WO4)2 are determined in the directions of the optical indicatrix axes Np, Nm and Ng in the temperature range of 60 – 300 °C using dilatometric technique.
{"title":"Growth and thermal expansion properties of KYbxY1-x(WO4)2 single crystals for laser applications","authors":"S.A. Guretskii , D.V. Karpinsky , E.L. Trukhanova , K.V. Yumashev , E.E. Trusova , N.V. Kuleshov","doi":"10.1016/j.jcrysgro.2025.128139","DOIUrl":"10.1016/j.jcrysgro.2025.128139","url":null,"abstract":"<div><div>Single crystals of KYb<sub>x</sub>Y<sub>1-x</sub>(WO<sub>4</sub>)<sub>2</sub> of high optical quality were grown at a rate of about</div><div>4.0 mm/day by the modified Czochralski method. The crystals have been grown using the so-called dynamic growth regime. The optimal temperature gradients have been determined at the crystallization front. Thermal expansion coefficients of KYb<em><sub>x</sub></em>Y<sub>1-</sub><em><sub>x</sub></em>(WO<sub>4</sub>)<sub>2</sub> are determined in the directions of the optical indicatrix axes N<sub>p</sub>, N<sub>m</sub> and N<sub>g</sub> in the temperature range of 60 – 300 °C using dilatometric technique.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"659 ","pages":"Article 128139"},"PeriodicalIF":1.7,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637319","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}
Pub Date : 2025-03-07DOI: 10.1016/j.jcrysgro.2025.128135
Muhammed Anees K.T., Souvik Kumar Rana, Abinash Das, Moumita Nandi
VSe is a highly promising van der Waals (vdW) material for applications in electronics, spintronics, and optoelectronics. Here, we report single crystal growth of 1T-VSe (octahedral structure) by flux method using eutectic of NaCl/KCl molten salt. The typical size of as-grown VSe single crystals is 5 × 4 × 0.1 mm. The elemental composition and homogeneity of the crystals were examined by energy dispersive x-ray spectroscopy, which is consistent with the stoichiometric ratio of VSe. The crystallographic [001] direction has been determined by x-ray diffraction. Raman measurement confirms that the octahedral 1T structure of VSe has been formed. Temperature-dependent resistivity measurement exhibits a transition around 104 K due to the formation of the charge density wave phase.
{"title":"Single crystal growth of 1T-VSe2 by molten salt flux method","authors":"Muhammed Anees K.T., Souvik Kumar Rana, Abinash Das, Moumita Nandi","doi":"10.1016/j.jcrysgro.2025.128135","DOIUrl":"10.1016/j.jcrysgro.2025.128135","url":null,"abstract":"<div><div>VSe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> is a highly promising van der Waals (vdW) material for applications in electronics, spintronics, and optoelectronics. Here, we report single crystal growth of 1T-VSe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> (octahedral structure) by flux method using eutectic of NaCl/KCl molten salt. The typical size of as-grown VSe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> single crystals is 5 × 4 × 0.1 mm<span><math><msup><mrow></mrow><mrow><mn>3</mn></mrow></msup></math></span>. The elemental composition and homogeneity of the crystals were examined by energy dispersive x-ray spectroscopy, which is consistent with the stoichiometric ratio of VSe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. The crystallographic [001] direction has been determined by x-ray diffraction. Raman measurement confirms that the octahedral 1T structure of VSe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> has been formed. Temperature-dependent resistivity measurement exhibits a transition around 104 K due to the formation of the charge density wave phase.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"659 ","pages":"Article 128135"},"PeriodicalIF":1.7,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143590358","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}
Pub Date : 2025-03-04DOI: 10.1016/j.jcrysgro.2025.128136
Na Pang, Zhiming Shi, Cunquan Wang, Hao Lian, Jiacheng Liu
The primary Al13Fe4 phase prefers to grow along the [010] orientation and form flakes, coarse needles, and lath shapes, which significantly impairs the mechanical properties of hypereutectic Al–Fe alloys. In this work, 1 wt% La addition is shown to greatly improve the morphology of the primary Al13Fe4 phase and have the most efficient refinement effect on Al–5Fe alloy. According to the data, La atoms mainly formed Al11La3 phase and were not found in the primary Al13Fe4 phase. The DSC thermal analysis revealed that La addition increased the crystallization temperature range and decreased the crystallization enthalpy of the primary Al13Fe4 phase. The results of the first-principles calculation indicated that La preferentially occupied Al sites when entering the primary Al13Fe4 phase, thus leading to an increase in the formation enthalpy of Al13Fe4. Meanwhile, the surface energy decreased and the stability of the (010) surface was enhanced when La atoms replaced the specific Al atoms sites in the Al13Fe4 (010) surface. Moreover, La atoms were rather adsorbed on the Al13Fe4 (010) surface because of the exothermic nature of adsorption and its negative energy. Therefore, La atoms change the formation enthalpy and surface energy of the Al13Fe4 phase by doping and adsorption, and finally affect the crystal structure, crystallization process and morphology of the primary Al13Fe4 phase. The experimental results and theoretical calculations confirm that adsorption and constitutional undercooling are more likely to be the main modification mechanisms of the primary Al13Fe4 phase via La doping.
{"title":"Modification mechanisms of the primary Al13Fe4 phase in hypereutectic Al–Fe alloys by La element: Experiments and first–principles study","authors":"Na Pang, Zhiming Shi, Cunquan Wang, Hao Lian, Jiacheng Liu","doi":"10.1016/j.jcrysgro.2025.128136","DOIUrl":"10.1016/j.jcrysgro.2025.128136","url":null,"abstract":"<div><div>The primary Al<sub>13</sub>Fe<sub>4</sub> phase prefers to grow along the [010] orientation and form flakes, coarse needles, and lath shapes, which significantly impairs the mechanical properties of hypereutectic Al–Fe alloys. In this work, 1 wt% La addition is shown to greatly improve the morphology of the primary Al<sub>13</sub>Fe<sub>4</sub> phase and have the most efficient refinement effect on Al–5Fe alloy. According to the data, La atoms mainly formed Al<sub>11</sub>La<sub>3</sub> phase and were not found in the primary Al<sub>13</sub>Fe<sub>4</sub> phase. The DSC thermal analysis revealed that La addition increased the crystallization temperature range and decreased the crystallization enthalpy of the primary Al<sub>13</sub>Fe<sub>4</sub> phase. The results of the first-principles calculation indicated that La preferentially occupied Al sites when entering the primary Al<sub>13</sub>Fe<sub>4</sub> phase, thus leading to an increase in the formation enthalpy of Al<sub>13</sub>Fe<sub>4</sub>. Meanwhile, the surface energy decreased and the stability of the (010) surface was enhanced when La atoms replaced the specific Al atoms sites in the Al<sub>13</sub>Fe<sub>4</sub> (010) surface. Moreover, La atoms were rather adsorbed on the Al<sub>13</sub>Fe<sub>4</sub> (010) surface because of the exothermic nature of adsorption and its negative energy. Therefore, La atoms change the formation enthalpy and surface energy of the Al<sub>13</sub>Fe<sub>4</sub> phase by doping and adsorption, and finally affect the crystal structure, crystallization process and morphology of the primary Al<sub>13</sub>Fe<sub>4</sub> phase. The experimental results and theoretical calculations confirm that adsorption and constitutional undercooling are more likely to be the main modification mechanisms of the primary Al<sub>13</sub>Fe<sub>4</sub> phase via La doping.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"659 ","pages":"Article 128136"},"PeriodicalIF":1.7,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577079","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号