The research work is devoted to study the influence of annealing temperature on the structural and optical properties of ZnSe thin films. The samples are prepared by a thermal evaporation technique and part of the as‐deposited films are annealed. X‐ray diffraction patterns and Raman spectra analysis reveal that the ZnSe thin films have cubic zinc‐blende crystal structure and the crystallinity increases as the annealing temperature increases. For the linear optical parameters, the absorption edge moves to shorter wavelengths with the increase of annealing temperature. Based on Swanepoel's method, the refractive index, film thickness, absorption coefficient and optical band gap are determined. The values of band gap are found to increase from 2.63 to 2.68 eV as the annealing temperature increases. By performing an open aperture Z‐scan technique with femtosecond pulses under 800 nm wavelength, all ZnSe samples show two‐photon absorption responses. It is found that the modulation depth and the two‐photon absorption coefficient decrease with increasing annealing temperature. Moreover, all samples exhibit better optical limiting responses at higher incident power intensities. These novel properties render this a promising material for traditional optoelectronic devices and optical limiters.
{"title":"Influence of Annealing Temperature Modulation on the Structural and Optical Properties of ZnSe Thin Films","authors":"Yafei Yuan, Chunmin Liu, Yaopeng Li, Jing Li","doi":"10.1002/crat.202000177","DOIUrl":"https://doi.org/10.1002/crat.202000177","url":null,"abstract":"The research work is devoted to study the influence of annealing temperature on the structural and optical properties of ZnSe thin films. The samples are prepared by a thermal evaporation technique and part of the as‐deposited films are annealed. X‐ray diffraction patterns and Raman spectra analysis reveal that the ZnSe thin films have cubic zinc‐blende crystal structure and the crystallinity increases as the annealing temperature increases. For the linear optical parameters, the absorption edge moves to shorter wavelengths with the increase of annealing temperature. Based on Swanepoel's method, the refractive index, film thickness, absorption coefficient and optical band gap are determined. The values of band gap are found to increase from 2.63 to 2.68 eV as the annealing temperature increases. By performing an open aperture Z‐scan technique with femtosecond pulses under 800 nm wavelength, all ZnSe samples show two‐photon absorption responses. It is found that the modulation depth and the two‐photon absorption coefficient decrease with increasing annealing temperature. Moreover, all samples exhibit better optical limiting responses at higher incident power intensities. These novel properties render this a promising material for traditional optoelectronic devices and optical limiters.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":"94 12 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85276080","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}
Chiraz Falah, Youssef Ben Smida, N. Sdiri, T. Soltani
New potassium bismuth phosphate K3Bi6.5(PO4)7.5 has been synthesized by solid‐state reaction and characterized by single‐crystal X‐ray diffraction. This compound crystallizes in the monoclinic system, space group C2, with a = 17.637(8) Å, b = 6.9261(8) Å, c = 22.385(4)Å, β = 104.35(2)°, and Z = 4. The crystal structure model is supported by the two methods; the charge distribution (CHARDI) and bond valence sum (BVS). The crystal structure is made up of BiOn (n = 5, 6, 7, 8) polyhedra and PO4 tetrahedra sharing corners and edges to form a three‐dimensional anionic framework. The bond valence sum energy (BVSE) model of simulation shows that the potassium atoms move along [101] direction with a zigzag pathways form with an empirical activation energy of about 1.56 eV. The dielectric properties are carried out at room temperature and show high permittivity values with low dielectric loss.
采用固相反应合成了新型磷酸铋钾K3Bi6.5(PO4)7.5，并用单晶X射线衍射对其进行了表征。该化合物在单斜晶系C2空间群中结晶，a = 17.637(8) Å， b = 6.9261(8) Å， c = 22.385(4)Å， β = 104.35(2)°，Z = 4。晶体结构模型得到了两种方法的支持;电荷分布(CHARDI)和键价和(BVS)。晶体结构由BiOn (n = 5,6,7,8)多面体和PO4四面体共享角和边组成，形成三维阴离子框架。模拟的键价和能(BVSE)模型表明，钾原子沿[101]方向以锯齿形路径运动，经验活化能约为1.56 eV。在室温下进行了介电性能测试，显示出高介电常数值和低介电损耗。
{"title":"Synthesis, Single‐Crystal Structure, Dielectric Properties of a New Phosphate K3Bi6.5(PO4)7.5","authors":"Chiraz Falah, Youssef Ben Smida, N. Sdiri, T. Soltani","doi":"10.1002/crat.202000228","DOIUrl":"https://doi.org/10.1002/crat.202000228","url":null,"abstract":"New potassium bismuth phosphate K3Bi6.5(PO4)7.5 has been synthesized by solid‐state reaction and characterized by single‐crystal X‐ray diffraction. This compound crystallizes in the monoclinic system, space group C2, with a = 17.637(8) Å, b = 6.9261(8) Å, c = 22.385(4)Å, β = 104.35(2)°, and Z = 4. The crystal structure model is supported by the two methods; the charge distribution (CHARDI) and bond valence sum (BVS). The crystal structure is made up of BiOn (n = 5, 6, 7, 8) polyhedra and PO4 tetrahedra sharing corners and edges to form a three‐dimensional anionic framework. The bond valence sum energy (BVSE) model of simulation shows that the potassium atoms move along [101] direction with a zigzag pathways form with an empirical activation energy of about 1.56 eV. The dielectric properties are carried out at room temperature and show high permittivity values with low dielectric loss.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":"106 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79266495","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}
K. Kozlovskaya, A. Kulikov, D. Novikov, E. Ovchinnikova, A. M. Ustyugov, V. Dmitrienko
Multiple‐wave X‐ray reflections usually aggravate the measurement of Bragg reflections, especially of weak “forbidden” reflections. Accurate analysis of multiple‐wave peaks usually allows to avoid this. However, multiple‐wave reflections can also provide information about crystal structure, since crystal cell parameters determine the positions of multi‐wave peaks. The forbidden reflections 002 and 100 in paratellurite are measured and an approach based on semi‐kinematical X‐ray scattering used to handle the multiple‐wave interferences is shown here.
{"title":"Handling of Multiple‐Wave Effects in the Measurement of Forbidden X‐Ray Reflections in TeO2","authors":"K. Kozlovskaya, A. Kulikov, D. Novikov, E. Ovchinnikova, A. M. Ustyugov, V. Dmitrienko","doi":"10.1002/crat.202000195","DOIUrl":"https://doi.org/10.1002/crat.202000195","url":null,"abstract":"Multiple‐wave X‐ray reflections usually aggravate the measurement of Bragg reflections, especially of weak “forbidden” reflections. Accurate analysis of multiple‐wave peaks usually allows to avoid this. However, multiple‐wave reflections can also provide information about crystal structure, since crystal cell parameters determine the positions of multi‐wave peaks. The forbidden reflections 002 and 100 in paratellurite are measured and an approach based on semi‐kinematical X‐ray scattering used to handle the multiple‐wave interferences is shown here.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":"69 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85255263","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}
P. Desai, Bhagyashri Todankar, A. Ranade, M. Kondo, Takehisa Dewa, M. Tanemura, G. Kalita
2D materials such as molybdenum sulfide (MoS2) integrated with conventional semiconductors lead to the fabrication of novel heterojunctions with pivotal electrical and optoelectronic properties. Herein, an approach is reported which addresses the growth of MoS2 crystals on the lattice‐matched Ga–polar gallium nitride (GaN) wafer using ammonium tetrathiomolybdate (ATM) as a precursor in a chemical vapor deposition (CVD) process, instead of using the molybdenum‐oxide‐based precursors. Unidirectional triangular MoS2 crystals and continuous film are obtained on the free‐standing Ga–polar GaN substrate. Further, the interface quality of the as‐synthesized MoS2 crystals and GaN wafer is explored by X‐ray photoelectron spectroscopy. It is observed that a good quality interface can be obtained by using the ammonia‐containing ATM precursor, where the surface oxygen at the interface is significantly less. A heterojunction device is fabricated with the synthesized MoS2 layer on GaN, showing excellent rectifying diode characteristics and a photovoltaic action with light illumination. This study reveals the suitability of the ammonia‐containing ATM precursor for the growth of MoS2 crystals on GaN in the CVD process to obtain a suitable heterostructure for device applications.
{"title":"Synthesis of MoS2 Layers on GaN Using Ammonium Tetrathiomolybdate for Heterojunction Device Applications","authors":"P. Desai, Bhagyashri Todankar, A. Ranade, M. Kondo, Takehisa Dewa, M. Tanemura, G. Kalita","doi":"10.1002/crat.202000198","DOIUrl":"https://doi.org/10.1002/crat.202000198","url":null,"abstract":"2D materials such as molybdenum sulfide (MoS2) integrated with conventional semiconductors lead to the fabrication of novel heterojunctions with pivotal electrical and optoelectronic properties. Herein, an approach is reported which addresses the growth of MoS2 crystals on the lattice‐matched Ga–polar gallium nitride (GaN) wafer using ammonium tetrathiomolybdate (ATM) as a precursor in a chemical vapor deposition (CVD) process, instead of using the molybdenum‐oxide‐based precursors. Unidirectional triangular MoS2 crystals and continuous film are obtained on the free‐standing Ga–polar GaN substrate. Further, the interface quality of the as‐synthesized MoS2 crystals and GaN wafer is explored by X‐ray photoelectron spectroscopy. It is observed that a good quality interface can be obtained by using the ammonia‐containing ATM precursor, where the surface oxygen at the interface is significantly less. A heterojunction device is fabricated with the synthesized MoS2 layer on GaN, showing excellent rectifying diode characteristics and a photovoltaic action with light illumination. This study reveals the suitability of the ammonia‐containing ATM precursor for the growth of MoS2 crystals on GaN in the CVD process to obtain a suitable heterostructure for device applications.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":"24 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73935035","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}
Determining the effect of casting geometric structure on freckle formation is important in designing the directional solidification parameter of single‐crystal superalloy castings. In this research, single‐crystal castings of a third‐generation nickel (Ni)‐based superalloy with different thicknesses and structures are prepared by conventional Bridgman high‐rate‐solidification technique at withdrawal rates of 1, 3, and 6 mm min–1. The experimental results show that the freckles in castings with expansion structures are severer than those with contraction structures at a withdrawal rate of 1 mm min–1, and vice versa at withdrawal rates of 3 and 6 mm min–1. It is found that the larger casting thickness tends to promote the freckle formation at the same withdrawal rate. Furthermore, a lower tendency is displayed at the withdrawal rate of 3 mm min–1 in freckle formation, whereas an increased tendency is displayed at the withdrawal rate of 6 mm min–1. The different withdrawal rates, thicknesses, and structures of casting cause differences in cooling rate, shrinkage flow, and mushy zone morphology, which are believed to be responsible for the tendency of freckle formation.
确定铸件几何结构对裂纹形成的影响对设计单晶高温合金铸件定向凝固参数具有重要意义。在本研究中，采用传统的Bridgman高速凝固技术，以1、3和6 mm min-1的拉伸速率制备了具有不同厚度和结构的第三代镍基高温合金单晶铸件。实验结果表明，在抽吸速率为1 mm min-1时，膨胀结构铸件的雀斑比收缩结构铸件的雀斑严重，抽吸速率为3和6 mm min-1时则相反。结果表明，在相同的拔模速率下，较大的铸件厚度有利于雀斑的形成。此外，当停药速率为3 mm min-1时，雀斑形成的趋势降低，而当停药速率为6 mm min-1时，雀斑形成的趋势增加。不同的提取速率、厚度和铸件结构导致冷却速度、收缩流动和糊状区形态的差异，这被认为是造成雀斑形成趋势的原因。
{"title":"Influence of Geometric Structure and Feeding Behavior of Casting on Freckle Formation during Directional Solidification of a Ni‐Based Single‐Crystal Superalloy","authors":"Dongyup Han, Weiguo Jiang, Jiu-han Xiao, Kai-wen Li, Yu-zhang Lu, L. Lou","doi":"10.1002/crat.202000197","DOIUrl":"https://doi.org/10.1002/crat.202000197","url":null,"abstract":"Determining the effect of casting geometric structure on freckle formation is important in designing the directional solidification parameter of single‐crystal superalloy castings. In this research, single‐crystal castings of a third‐generation nickel (Ni)‐based superalloy with different thicknesses and structures are prepared by conventional Bridgman high‐rate‐solidification technique at withdrawal rates of 1, 3, and 6 mm min–1. The experimental results show that the freckles in castings with expansion structures are severer than those with contraction structures at a withdrawal rate of 1 mm min–1, and vice versa at withdrawal rates of 3 and 6 mm min–1. It is found that the larger casting thickness tends to promote the freckle formation at the same withdrawal rate. Furthermore, a lower tendency is displayed at the withdrawal rate of 3 mm min–1 in freckle formation, whereas an increased tendency is displayed at the withdrawal rate of 6 mm min–1. The different withdrawal rates, thicknesses, and structures of casting cause differences in cooling rate, shrinkage flow, and mushy zone morphology, which are believed to be responsible for the tendency of freckle formation.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":"36 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80819407","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}
Crystal agglomeration is an important factor that can affect the purity and crystal habit of crystalline products. Agglomeration of niacin crystals in its cooling crystallization and its mechanism is investigated using both experimental and molecular dynamics simulation methods. The magnitude of the interaction energy which is mainly contributed by the hydrogen bond and π–π stacking between the (0 1 1) crystal face and (1 1 −1) crystal face that have both the pyridine and carboxyl groups is the main factor determining the extent of agglomeration of niacin crystal. Besides, the interaction energy increases with the crystallization temperature and the supersaturation of the solution, and hence the agglomeration is more severe. The change of solvent species has minimal effect on the agglomeration of crystals. Besides, the agglomeration situation of carbamazepine and acetaminophen that with similar structures to niacin is also verified using molecular dynamics simulations. The findings in this work can be used to predict, control the agglomeration phenomenon, and optimize the crystallization process of niacin and other substances with similar chemical structure.
{"title":"The Agglomeration of Niacin Crystals in the Cooling Crystallization Process","authors":"Lei Wang, Min Su","doi":"10.1002/crat.202000209","DOIUrl":"https://doi.org/10.1002/crat.202000209","url":null,"abstract":"Crystal agglomeration is an important factor that can affect the purity and crystal habit of crystalline products. Agglomeration of niacin crystals in its cooling crystallization and its mechanism is investigated using both experimental and molecular dynamics simulation methods. The magnitude of the interaction energy which is mainly contributed by the hydrogen bond and π–π stacking between the (0 1 1) crystal face and (1 1 −1) crystal face that have both the pyridine and carboxyl groups is the main factor determining the extent of agglomeration of niacin crystal. Besides, the interaction energy increases with the crystallization temperature and the supersaturation of the solution, and hence the agglomeration is more severe. The change of solvent species has minimal effect on the agglomeration of crystals. Besides, the agglomeration situation of carbamazepine and acetaminophen that with similar structures to niacin is also verified using molecular dynamics simulations. The findings in this work can be used to predict, control the agglomeration phenomenon, and optimize the crystallization process of niacin and other substances with similar chemical structure.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":"70 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85345454","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}
Zhiyuan Han, D. Sun, Huili Zhang, Jianqiao Luo, Cong Quan, Lunzhen Hu, Kunpeng Dong, M. Cheng, Guangzhu Chen, Y. Hang
Large lattice constant Y3Al5O12, Gd3Ga5O12 (GGG), Y3Sc2Ga3O12 (YSGG), Gd3Sc2Ga3O12, Ca0.4Mg0.25Zr0.65Gd2.6Ga4.1O12 (CaMgZr:GGG), and Gd1.17Y1.83Sc2Ga3O12 (GYSGG) substrate crystals with 2 in. in diameter are grown by the Czochralski (Cz) method, their physical, chemical, and optical properties are analyzed and compared in details. The X‐ray rocking curves (XRCs) illustrate that the as‐grown crystals possess high crystalline quality. The lattice constants of six crystals are calculated and that of GYSGG can be easily adjusted in the range of 1.2450–1.2565 nm by changing the Gd/Y proportion. The dislocation densities on the (111)‐crystalline face are about 102 cm−2 order of magnitude. The thermal conductivities of six crystals are measured to be 11.72, 8.98, 6.83, 5.45, 4.67, and 4.66 W m−1 K−1, respectively. It is found that the thermal expansion coefficients of six crystals can be reduced by annealing at 1273 K for 60 h. In addition, the transmission spectra show that the six crystals have excellent transparency and the coefficients of the Sellmeier equation are fitted by the calculated refractive indices. These results of the six crystals can provide the necessary parameters and references for the selection of suitable substrate materials or laser host crystals.
{"title":"Investigation on the Growth and Properties of Six Garnet Single Crystals with Large Lattice Constants","authors":"Zhiyuan Han, D. Sun, Huili Zhang, Jianqiao Luo, Cong Quan, Lunzhen Hu, Kunpeng Dong, M. Cheng, Guangzhu Chen, Y. Hang","doi":"10.1002/crat.202000221","DOIUrl":"https://doi.org/10.1002/crat.202000221","url":null,"abstract":"Large lattice constant Y3Al5O12, Gd3Ga5O12 (GGG), Y3Sc2Ga3O12 (YSGG), Gd3Sc2Ga3O12, Ca0.4Mg0.25Zr0.65Gd2.6Ga4.1O12 (CaMgZr:GGG), and Gd1.17Y1.83Sc2Ga3O12 (GYSGG) substrate crystals with 2 in. in diameter are grown by the Czochralski (Cz) method, their physical, chemical, and optical properties are analyzed and compared in details. The X‐ray rocking curves (XRCs) illustrate that the as‐grown crystals possess high crystalline quality. The lattice constants of six crystals are calculated and that of GYSGG can be easily adjusted in the range of 1.2450–1.2565 nm by changing the Gd/Y proportion. The dislocation densities on the (111)‐crystalline face are about 102 cm−2 order of magnitude. The thermal conductivities of six crystals are measured to be 11.72, 8.98, 6.83, 5.45, 4.67, and 4.66 W m−1 K−1, respectively. It is found that the thermal expansion coefficients of six crystals can be reduced by annealing at 1273 K for 60 h. In addition, the transmission spectra show that the six crystals have excellent transparency and the coefficients of the Sellmeier equation are fitted by the calculated refractive indices. These results of the six crystals can provide the necessary parameters and references for the selection of suitable substrate materials or laser host crystals.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":"67 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77284891","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}
This study uses a cooling sonocrystallization process to recrystallize an active pharmaceutical ingredient, probenecid, and to improve the crystal qualities such as crystal habit and particle size characteristics. To screen the appropriate solvent system, solubility data of probenecid in organic solvent are measured, reported, and correlated by van't Hoff equation. According to the measured solubilities and data acquired from literature, sonocrystallization experiments using solvents with acceptable theoretical recovery are performed. Owing to the satisfactory throughput, yield, and crystal qualities, ethanol is finally decided as the appropriate solvent system. The effect of operating parameters in sonocrystallization including the solution concentration, sonication intensity, sonication duration, and cooling rate using ethanol as the solvent is further studied. With applying power ultrasound, probenecid crystals with narrow size distribution, regular crystal habit, and mean size around 15 µm are successfully produced. Finally, crystal form and spectroscopic property of sonocrystallized sample and probenecid as received from the supplier are compared and confirmed consistent from the analytical results of powder X‐ray diffractometer and Fourier transform infrared spectroscopy.
{"title":"Particle Size and Crystal Habit Modification of Active Pharmaceutical Ingredient Using Cooling Sonocrystallization: A Case Study of Probenecid","authors":"Chun-Hao Chang, Chieh-Ming Hsieh, Chie-Shaan Su","doi":"10.1002/crat.202000182","DOIUrl":"https://doi.org/10.1002/crat.202000182","url":null,"abstract":"This study uses a cooling sonocrystallization process to recrystallize an active pharmaceutical ingredient, probenecid, and to improve the crystal qualities such as crystal habit and particle size characteristics. To screen the appropriate solvent system, solubility data of probenecid in organic solvent are measured, reported, and correlated by van't Hoff equation. According to the measured solubilities and data acquired from literature, sonocrystallization experiments using solvents with acceptable theoretical recovery are performed. Owing to the satisfactory throughput, yield, and crystal qualities, ethanol is finally decided as the appropriate solvent system. The effect of operating parameters in sonocrystallization including the solution concentration, sonication intensity, sonication duration, and cooling rate using ethanol as the solvent is further studied. With applying power ultrasound, probenecid crystals with narrow size distribution, regular crystal habit, and mean size around 15 µm are successfully produced. Finally, crystal form and spectroscopic property of sonocrystallized sample and probenecid as received from the supplier are compared and confirmed consistent from the analytical results of powder X‐ray diffractometer and Fourier transform infrared spectroscopy.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":"4 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80675089","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}
T. Hagio, Jae-Hyeok Park, Yan Lin, Yanqin Tian, Y. Hu, Xinling Li, Y. Kamimoto, R. Ichino
Conventionally, EAB‐type zeolites are crystallized by hydrothermal synthesis for many days under agitational synthesis conditions such as rotation or stirring. In the present study, EAB‐type zeolite is obtained by hydrothermal synthesis within 12 h under static synthesis conditions for the first time. The effects of crystallization temperature, aging of the precursor sol, and addition of seed crystals are investigated. The results reveal that EAB‐type zeolite can be obtained when using a precursor sol with short aging time followed by hydrothermal synthesis in a very narrow temperature range 110 °C−120 °C under static synthesis condition. Addition of seed crystals is found to suppress the formation of SOD‐type zeolite, the primary phase at high hydrothermal synthesis temperatures, while it does not increase the crystallization rate of EAB‐type zeolite. Furthermore, the crystallization behavior at 120 °C is examined by varying the synthesis time. EAB‐type zeolite with invariably twinned plate‐like morphology starts to crystallize between synthesis time of 3 to 6 h at 120 °C under the static synthesis condition.
{"title":"Facile Hydrothermal Synthesis of EAB‐Type Zeolite under Static Synthesis Conditions","authors":"T. Hagio, Jae-Hyeok Park, Yan Lin, Yanqin Tian, Y. Hu, Xinling Li, Y. Kamimoto, R. Ichino","doi":"10.1002/crat.202000163","DOIUrl":"https://doi.org/10.1002/crat.202000163","url":null,"abstract":"Conventionally, EAB‐type zeolites are crystallized by hydrothermal synthesis for many days under agitational synthesis conditions such as rotation or stirring. In the present study, EAB‐type zeolite is obtained by hydrothermal synthesis within 12 h under static synthesis conditions for the first time. The effects of crystallization temperature, aging of the precursor sol, and addition of seed crystals are investigated. The results reveal that EAB‐type zeolite can be obtained when using a precursor sol with short aging time followed by hydrothermal synthesis in a very narrow temperature range 110 °C−120 °C under static synthesis condition. Addition of seed crystals is found to suppress the formation of SOD‐type zeolite, the primary phase at high hydrothermal synthesis temperatures, while it does not increase the crystallization rate of EAB‐type zeolite. Furthermore, the crystallization behavior at 120 °C is examined by varying the synthesis time. EAB‐type zeolite with invariably twinned plate‐like morphology starts to crystallize between synthesis time of 3 to 6 h at 120 °C under the static synthesis condition.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":"210 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75649946","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}
The single crystal form and uncontrollable topography of CaCO3 in nature severely restrict its product grade and application. Meanwhile, lignin is still not utilized efficiently. In order to improve this, three types of lignin monomer model compounds as p‐coumaric acid (PCA), ferulic acid (FA), and sinapic acid (SA) are employed to induce the growth of CaCO3 to investigate the relationship between lignin structure and CaCO3 crystallization. The synthesized PCA and CaCO3 composite crystals (PC‐ACCs), FA and CaCO3 composite crystals (F‐ACCs), and SA and CaCO3 composite crystals (S‐ACCs) are characterized by field emission scanning electron microscope (FESEM), X‐ray diffraction (XRD), and Fourier transmission infrared spectroscopy (FTIR) to ascertain their molecular structures and crystal information. The growth rule of the acid and CaCO3 composite crystals (ACCs) induced by the three units is also explored. The results show that the vaterite and calcite of ACCs can be formed selectively. In the presence of PCA, FA, and SA, pH is the key factor on the phase selection of ACCs. The temperature and organic acid type also play important roles on the formation of CaCO3. The ACCs present distinguishing surface topographies at different temperatures. The number of methoxyl in the PCA, FA, and SA decides the phase ratio of vaterite and calcite in the ACCs.
{"title":"Formation and Phase Selection of CaCO3 in the Intervention of Lignin Monomer Model Compounds","authors":"Huifeng Hu, Fugen Liang, Haidong Zhu, X. Zhang, Kecong Cui, Hridam Deb, Yong Zhang","doi":"10.1002/crat.202000187","DOIUrl":"https://doi.org/10.1002/crat.202000187","url":null,"abstract":"The single crystal form and uncontrollable topography of CaCO3 in nature severely restrict its product grade and application. Meanwhile, lignin is still not utilized efficiently. In order to improve this, three types of lignin monomer model compounds as p‐coumaric acid (PCA), ferulic acid (FA), and sinapic acid (SA) are employed to induce the growth of CaCO3 to investigate the relationship between lignin structure and CaCO3 crystallization. The synthesized PCA and CaCO3 composite crystals (PC‐ACCs), FA and CaCO3 composite crystals (F‐ACCs), and SA and CaCO3 composite crystals (S‐ACCs) are characterized by field emission scanning electron microscope (FESEM), X‐ray diffraction (XRD), and Fourier transmission infrared spectroscopy (FTIR) to ascertain their molecular structures and crystal information. The growth rule of the acid and CaCO3 composite crystals (ACCs) induced by the three units is also explored. The results show that the vaterite and calcite of ACCs can be formed selectively. In the presence of PCA, FA, and SA, pH is the key factor on the phase selection of ACCs. The temperature and organic acid type also play important roles on the formation of CaCO3. The ACCs present distinguishing surface topographies at different temperatures. The number of methoxyl in the PCA, FA, and SA decides the phase ratio of vaterite and calcite in the ACCs.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":"46 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87805772","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：