Aaron Hunsaker, W. Goodwin, E. Rowe, C. Wheeler, L. Matei, V. Buliga, A. Burger
Single crystal scintillators have become one of the most common materials used in technologies that use radiation detectors. Unfortunately, as technology demands improved detectors, research into better single crystal scintillators has nearly reached its limit. Ceramics provide many benefits over single crystal scintillators and have emerged as a promising new production process. Recent research into ceramic scintillators has mostly dealt with oxides as they are relatively easy to handle and are typically non‐hygroscopic. Among single crystal scintillators, a trend has emerged indicating that the addition of halide ions into the crystal structure improves the light yield and energy resolution of the scintillation material but also tends to make the material hygroscopic and in some cases intrinsically radioactive. Little research is devoted to the investigation of undoped halide ceramic scintillators. Transparent halide Cs2HfCl6 ceramics are developed by hot uniaxial pressing, and the scintillation properties are compared to that of its single crystal counterpart. The energy resolution of the ceramic is found to be 6.4% at 662 keV. The initial results indicate that ceramic scintillators are a viable alternative and a promising new direction in scintillator material technology.
{"title":"Ceramic Cs2HfCl6: A Novel Scintillation Material for Use in Gamma Ray Spectroscopy","authors":"Aaron Hunsaker, W. Goodwin, E. Rowe, C. Wheeler, L. Matei, V. Buliga, A. Burger","doi":"10.1002/crat.202000166","DOIUrl":"https://doi.org/10.1002/crat.202000166","url":null,"abstract":"Single crystal scintillators have become one of the most common materials used in technologies that use radiation detectors. Unfortunately, as technology demands improved detectors, research into better single crystal scintillators has nearly reached its limit. Ceramics provide many benefits over single crystal scintillators and have emerged as a promising new production process. Recent research into ceramic scintillators has mostly dealt with oxides as they are relatively easy to handle and are typically non‐hygroscopic. Among single crystal scintillators, a trend has emerged indicating that the addition of halide ions into the crystal structure improves the light yield and energy resolution of the scintillation material but also tends to make the material hygroscopic and in some cases intrinsically radioactive. Little research is devoted to the investigation of undoped halide ceramic scintillators. Transparent halide Cs2HfCl6 ceramics are developed by hot uniaxial pressing, and the scintillation properties are compared to that of its single crystal counterpart. The energy resolution of the ceramic is found to be 6.4% at 662 keV. The initial results indicate that ceramic scintillators are a viable alternative and a promising new direction in scintillator material technology.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90886019","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. Sivakumar, P. Eniya, J. Sundar, Arisiappan Thirunavukkarasu, M. A. Lakshmi, G. Kanthimathi
The intent is to explore the optoelectronic properties of metal ions doped stilbazolium derivative, 4‐N,N′‐dimethylamino‐N‐methyl‐4‐stilbazolium tosylate (MnCl2‐DAST) nonlinear optical crystal materials for the existing technological necessities. The Mn‐DAST single crystals are crystallized by adopting the slow evaporation solution technique (SEST). The structural and crystallographic dimensions of grown crystals are affirmed using single‐crystal X‐ray diffraction and powder crystal X‐ray diffraction. Fourier transform infrared spectra are performed to explicate the functional groups and energy dispersive X‐ray analysis (EDAX) spectra confirm the presence of the chemical elements of grown crystals. The UV–vis absorption spectra of DAST and Mn‐DAST crystals exhibit all possible n–π* and π–π* electronic transitions. The blue shift is observed in the doped materials due to the exchange of lone pair electrons between the metal ions and organic molecule. Tremendously, the second order harmonic generation (SHG) efficiency of Mn (0.01 mol%) doped DAST crystals has 1.68 times larger than that of DAST crystal. From the metal‐organic crystals (Mn‐DAST), all the results brought out are the promising materials in the design of nonlinear optical applications.
{"title":"Investigation on the Effects of MnCl2 Doping on Structural and Optical Properties of DAST Single Crystals as Materials for Second Order Nonlinear Optics","authors":"T. Sivakumar, P. Eniya, J. Sundar, Arisiappan Thirunavukkarasu, M. A. Lakshmi, G. Kanthimathi","doi":"10.1002/crat.202100016","DOIUrl":"https://doi.org/10.1002/crat.202100016","url":null,"abstract":"The intent is to explore the optoelectronic properties of metal ions doped stilbazolium derivative, 4‐N,N′‐dimethylamino‐N‐methyl‐4‐stilbazolium tosylate (MnCl2‐DAST) nonlinear optical crystal materials for the existing technological necessities. The Mn‐DAST single crystals are crystallized by adopting the slow evaporation solution technique (SEST). The structural and crystallographic dimensions of grown crystals are affirmed using single‐crystal X‐ray diffraction and powder crystal X‐ray diffraction. Fourier transform infrared spectra are performed to explicate the functional groups and energy dispersive X‐ray analysis (EDAX) spectra confirm the presence of the chemical elements of grown crystals. The UV–vis absorption spectra of DAST and Mn‐DAST crystals exhibit all possible n–π* and π–π* electronic transitions. The blue shift is observed in the doped materials due to the exchange of lone pair electrons between the metal ions and organic molecule. Tremendously, the second order harmonic generation (SHG) efficiency of Mn (0.01 mol%) doped DAST crystals has 1.68 times larger than that of DAST crystal. From the metal‐organic crystals (Mn‐DAST), all the results brought out are the promising materials in the design of nonlinear optical applications.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87635974","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}
Ramalingam Thirumurugan, Singaravelu Ramalingam, S. Periandy., R. Aarthi
In this work, the semi‐organic, 2‐aminofluorene single‐crystal is grown by slow evaporation method. The crystal is optimized and determination of optical axis and the crystal sample is characterized. The volume of the crystal is 568.22 Å3and density −1.311 mg cm−3. The XRD parameters estimate crystal lattice as orthorhombic. The birefringence effect is measured with inter‐atomic attractive dispersion forces. The rearrangement of molecular frame of fluorine on par with amino substitution is estimated. The electro‐optic effect is established by parametric oscillations of accumulation of chemical potential to enable the mechanism of nonlinear optical (NLO) effect. The dielectric loss with respect to the temperature/electrical frequency and the active optical property is measured. The amino group causes optical scattering of nodal regions for radiation absorption process to fascinate optical endurance. The chemical energy processing to acquire the chemical potential to operate light frequency amplification is thoroughly studied from the observation of chemical shift over the molecular frame. The oscillated parametric energy on nonbonding molecular orbital (NBMO) is initiated by the NH2group on the ring carbon–carbon (CC) and it is exchanged among nodal zones of core and comprised of the above segments of the ring.
{"title":"Optoelectronic Evaluation, Chemical Potential Identification, Chemiparametric Oscillation Mapping, and Dielectric Efficiency Investigation of Organic NLO Crystal: 2‐Aminofluorene Using Computational Calculations","authors":"Ramalingam Thirumurugan, Singaravelu Ramalingam, S. Periandy., R. Aarthi","doi":"10.1002/crat.202100062","DOIUrl":"https://doi.org/10.1002/crat.202100062","url":null,"abstract":"In this work, the semi‐organic, 2‐aminofluorene single‐crystal is grown by slow evaporation method. The crystal is optimized and determination of optical axis and the crystal sample is characterized. The volume of the crystal is 568.22 Å3and density −1.311 mg cm−3. The XRD parameters estimate crystal lattice as orthorhombic. The birefringence effect is measured with inter‐atomic attractive dispersion forces. The rearrangement of molecular frame of fluorine on par with amino substitution is estimated. The electro‐optic effect is established by parametric oscillations of accumulation of chemical potential to enable the mechanism of nonlinear optical (NLO) effect. The dielectric loss with respect to the temperature/electrical frequency and the active optical property is measured. The amino group causes optical scattering of nodal regions for radiation absorption process to fascinate optical endurance. The chemical energy processing to acquire the chemical potential to operate light frequency amplification is thoroughly studied from the observation of chemical shift over the molecular frame. The oscillated parametric energy on nonbonding molecular orbital (NBMO) is initiated by the NH2group on the ring carbon–carbon (CC) and it is exchanged among nodal zones of core and comprised of the above segments of the ring.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75941972","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}
In this paper, two new Rivaroxaban crystalline forms are reported and characterized by the single‐crystal X‐ray diffraction (SXRD), powder X‐ray diffraction (PXRD), thermogravimetric analysis, and differential scanning calorimetry (TGA/DSC), which are synthesized with formic acid and acetic acid, named as forms F and G, respectively. The intermolecular forces for forms F and G are analyzed by Hirshfeld surface analysis method, showing that the force of O···H is significantly stronger than that of H···H. Furthermore, the stability, solubility, and bioavailability of the two crystal forms are also studied. The clinical experiments show that form F is more effective than other reported crystal forms in inhibiting the activity of thrombin and thrombosis, which is expected to replace the marketed crystalline forms in clinical application.
{"title":"Synthesis, Characterization, and Properties of Rivaroxaban New Crystalline Forms","authors":"L. Zhai, Zhaohua Zhang, Lihong Guo, Zhiying Zhu, Changkai Hu, Guimin Zhang","doi":"10.1002/crat.202000243","DOIUrl":"https://doi.org/10.1002/crat.202000243","url":null,"abstract":"In this paper, two new Rivaroxaban crystalline forms are reported and characterized by the single‐crystal X‐ray diffraction (SXRD), powder X‐ray diffraction (PXRD), thermogravimetric analysis, and differential scanning calorimetry (TGA/DSC), which are synthesized with formic acid and acetic acid, named as forms F and G, respectively. The intermolecular forces for forms F and G are analyzed by Hirshfeld surface analysis method, showing that the force of O···H is significantly stronger than that of H···H. Furthermore, the stability, solubility, and bioavailability of the two crystal forms are also studied. The clinical experiments show that form F is more effective than other reported crystal forms in inhibiting the activity of thrombin and thrombosis, which is expected to replace the marketed crystalline forms in clinical application.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87224416","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}
M. Divya, P. Malliga, P. Sagayaraj, A. Joseph Arul Pragasam
Dielectric, thermal, and mechanical behavior of an efficient nonlinear crystal, nickel boro phthalate (NBP), grown by a slow evaporation solution growth technique, is characterized for optoelectronic applications. Ultraviolet absorption study identifies the lower cutoff wavelength as 281 nm. This low value along with transparency in the visible and infrared regions establishes that NBP is a probable nonlinear material. The frequency and the temperature dependency of dielectric constant and dielectric loss are probed. AC conductivity and activation energy are computed, to examine the semiconducting ability of the crystal. Thermal gravimetric analysis and differential thermal analysis are carried out to determine the decomposition temperature. Mechanical characterization is performed by the Vickers microhardness test. The study reveals that NBP comes under the category of soft material. Mechanical properties such as the elastic stiffness constant, brittleness index, yield strength, and fracture toughness are explored.
{"title":"Analysis on Dielectric, Thermal, and Mechanical Characteristics of Nickel Boro Phthalate NLO Crystal for Optoelectronic Applications","authors":"M. Divya, P. Malliga, P. Sagayaraj, A. Joseph Arul Pragasam","doi":"10.1002/crat.202000247","DOIUrl":"https://doi.org/10.1002/crat.202000247","url":null,"abstract":"Dielectric, thermal, and mechanical behavior of an efficient nonlinear crystal, nickel boro phthalate (NBP), grown by a slow evaporation solution growth technique, is characterized for optoelectronic applications. Ultraviolet absorption study identifies the lower cutoff wavelength as 281 nm. This low value along with transparency in the visible and infrared regions establishes that NBP is a probable nonlinear material. The frequency and the temperature dependency of dielectric constant and dielectric loss are probed. AC conductivity and activation energy are computed, to examine the semiconducting ability of the crystal. Thermal gravimetric analysis and differential thermal analysis are carried out to determine the decomposition temperature. Mechanical characterization is performed by the Vickers microhardness test. The study reveals that NBP comes under the category of soft material. Mechanical properties such as the elastic stiffness constant, brittleness index, yield strength, and fracture toughness are explored.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77604889","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}
Xuran Guo, Wei Chen, Rongli Wei, Jingchen Sui, Xin Huang, Na Wang, Songqiang Liu, Ting Wang, H. Hao
The stability of solvates is very important in the field of crystal engineering. Molecular interaction and packing mode are important factors affecting the stability of solvates. In this study, 2,7‐dibromo‐9H‐carbazole is selected as the model compound to investigate the influence of molecular stacking mode on the stability of solvates. An anhydrous form and five solvates of 2,7‐dibromo‐9H‐carbazole are obtained by recrystallization. The desolvation phenomena of the five solvates are studied by thermogravimetric analysis, hot stage microscope, and infrared spectroscopy and it is found that the stability of the solvates is N,N‐dimethylacetamide solvate > dimethyl sulfoxide solvate > N,N‐dimethylformamide solvate > dioxane solvate > acetonitrile solvate. Crystal structures are analyzed by single crystal X‐ray diffraction and Hirshfeld surface analysis is also applied to analyze the intermolecular interactions in the crystals. The results show that the stability of the five solvates is related to the packing modes of the molecules in the crystal. It is suggested that the solute molecules and solvent molecules in the unstable solvates are arranged in the interlayer mode, while they are arranged in a staggered mode in stable solvates.
{"title":"Various Molecular Arrangements Leading to Different Desolvation Rates: Research on the Stability of 2,7‐Dibromo‐9H‐carbazole Solvates","authors":"Xuran Guo, Wei Chen, Rongli Wei, Jingchen Sui, Xin Huang, Na Wang, Songqiang Liu, Ting Wang, H. Hao","doi":"10.1002/crat.202100059","DOIUrl":"https://doi.org/10.1002/crat.202100059","url":null,"abstract":"The stability of solvates is very important in the field of crystal engineering. Molecular interaction and packing mode are important factors affecting the stability of solvates. In this study, 2,7‐dibromo‐9H‐carbazole is selected as the model compound to investigate the influence of molecular stacking mode on the stability of solvates. An anhydrous form and five solvates of 2,7‐dibromo‐9H‐carbazole are obtained by recrystallization. The desolvation phenomena of the five solvates are studied by thermogravimetric analysis, hot stage microscope, and infrared spectroscopy and it is found that the stability of the solvates is N,N‐dimethylacetamide solvate > dimethyl sulfoxide solvate > N,N‐dimethylformamide solvate > dioxane solvate > acetonitrile solvate. Crystal structures are analyzed by single crystal X‐ray diffraction and Hirshfeld surface analysis is also applied to analyze the intermolecular interactions in the crystals. The results show that the stability of the five solvates is related to the packing modes of the molecules in the crystal. It is suggested that the solute molecules and solvent molecules in the unstable solvates are arranged in the interlayer mode, while they are arranged in a staggered mode in stable solvates.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84084202","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}
Qinjiang Zhao, Lihong Zhou, Jie Du, Guanghui Wang, X. Pei
As an ecological and environment‐friendly building material, sticky rice mortar has attracted the attention of many researchers. Amylopectin is the most important organic matter of it, which can improve the mechanical properties and durability of sticky rice mortar by inducing mineralization of calcium carbonate (CaCO3). However, amylopectin induced formation of CaCO3 has not been reported. In this paper, mineralization of CaCO3 induced by gelatinized amylopectin is investigated. For comparison, the different morphologies of CaCO3 are studied in the presence of Mg2+, Fe3+. Moreover, these CaCO3 products with different morphologies are used to clean the waste water. The results indicate that gelatinized amylopectin is conducive to formation of pumpkin‐like vaterite. It forms uniform rod and dumbbell‐shaped calcite in the presence of Mg2+, form calcite with stepped depressions in the presence of Fe3+. The adsorption of Pb(II) can reach extremely high level (1445.86 mg g−1) with the rod‐like calcite.
{"title":"Amylopectin Regulated Mineralization of Calcium Carbonate and Its Application in Removing of Pb(II)","authors":"Qinjiang Zhao, Lihong Zhou, Jie Du, Guanghui Wang, X. Pei","doi":"10.1002/crat.202100012","DOIUrl":"https://doi.org/10.1002/crat.202100012","url":null,"abstract":"As an ecological and environment‐friendly building material, sticky rice mortar has attracted the attention of many researchers. Amylopectin is the most important organic matter of it, which can improve the mechanical properties and durability of sticky rice mortar by inducing mineralization of calcium carbonate (CaCO3). However, amylopectin induced formation of CaCO3 has not been reported. In this paper, mineralization of CaCO3 induced by gelatinized amylopectin is investigated. For comparison, the different morphologies of CaCO3 are studied in the presence of Mg2+, Fe3+. Moreover, these CaCO3 products with different morphologies are used to clean the waste water. The results indicate that gelatinized amylopectin is conducive to formation of pumpkin‐like vaterite. It forms uniform rod and dumbbell‐shaped calcite in the presence of Mg2+, form calcite with stepped depressions in the presence of Fe3+. The adsorption of Pb(II) can reach extremely high level (1445.86 mg g−1) with the rod‐like calcite.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74798542","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}
F. Cao, Fei Li, Zhiyong Yuan, Lunyong Zhang, Sida Jiang, Hongxian Shen, Z. Ning, Yongjiang Huang, D. Xing, H. Zuo, Jiecai Han, Jianfei Sun
In this work, the dislocation etching pit morphology and etching kinetics on the A‐{11 2¯ 0} plane of sapphire crystal (α‐Al2O3) are studied experimentally. The results show that the etch pit exhibits a subrhombic 3D morphology, which is consistent with the atom arrangement symmetry of the A plane. Further analysis shows that the two adjacent sides of the rhombic etch pits correspond to the directions [3 3¯ 0 1¯ ] and [3 3¯ 02], respectively; both of them are in the atomic close‐packing direction of A plane. The etch pits are controlled by a chemical reaction between Al2O3 and potassium hydroxide (KOH) with the reaction activation energy of 51.7 kJ mol−1, which is developed in a manner of kinematic wave by the step moving with a constant speed.
{"title":"Dislocation Etching Morphology on the A Plane of Sapphire Crystal","authors":"F. Cao, Fei Li, Zhiyong Yuan, Lunyong Zhang, Sida Jiang, Hongxian Shen, Z. Ning, Yongjiang Huang, D. Xing, H. Zuo, Jiecai Han, Jianfei Sun","doi":"10.1002/crat.202100022","DOIUrl":"https://doi.org/10.1002/crat.202100022","url":null,"abstract":"In this work, the dislocation etching pit morphology and etching kinetics on the A‐{11 2¯ 0} plane of sapphire crystal (α‐Al2O3) are studied experimentally. The results show that the etch pit exhibits a subrhombic 3D morphology, which is consistent with the atom arrangement symmetry of the A plane. Further analysis shows that the two adjacent sides of the rhombic etch pits correspond to the directions [3 3¯ 0 1¯ ] and [3 3¯ 02], respectively; both of them are in the atomic close‐packing direction of A plane. The etch pits are controlled by a chemical reaction between Al2O3 and potassium hydroxide (KOH) with the reaction activation energy of 51.7 kJ mol−1, which is developed in a manner of kinematic wave by the step moving with a constant speed.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74517125","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}
A simple method for synthesis of titanium carbide (TiC) nanofibers by a modified carbothermal reduction of electrospun titanium‐based fibers is reported. The effect of synthesis steps on the final product is discussed. Continuous TiC fibers synthesized have a smooth surface morphology, with average diameter of 148 nm and length in the centimeter range. X‐ray diffraction and high‐resolution transmission electron microscopy analysis results indicate that the fibers consist of TiC of high purity. Impact of heat treatment on the morphology and chemical and crystalline composition of the product is also investigated. Based on the experimental evidence, it is hypothesized that the carbothermal reduction of calcined electrospun fibers with precoated carbon proceeds through diffusion‐limited shrinking core pathway while that of the as‐spun fibers follows the reaction‐limited solution precipitation mechanism. The TiC nanofibers also show superior sintering properties by increasing theoretical density of hot pressed TiB2 from 94.5% of theoretical density to 97.9% of theoretical density. When sintered with ceria, it improves the conductivity of the ceria by 18.29 times as compared to 2.94 times by TiC nanoparticles at 800 °C. The TiC nanofibers show metallic behavior as well as potential for application as electrochemical double layer capacitor supercapacitors.
{"title":"Synthesis and Characterization of TiC Nanofibers Obtained via a Modified Carbothermal Process","authors":"Chung‐Ying Tsai, K. Mondal","doi":"10.1002/crat.202000231","DOIUrl":"https://doi.org/10.1002/crat.202000231","url":null,"abstract":"A simple method for synthesis of titanium carbide (TiC) nanofibers by a modified carbothermal reduction of electrospun titanium‐based fibers is reported. The effect of synthesis steps on the final product is discussed. Continuous TiC fibers synthesized have a smooth surface morphology, with average diameter of 148 nm and length in the centimeter range. X‐ray diffraction and high‐resolution transmission electron microscopy analysis results indicate that the fibers consist of TiC of high purity. Impact of heat treatment on the morphology and chemical and crystalline composition of the product is also investigated. Based on the experimental evidence, it is hypothesized that the carbothermal reduction of calcined electrospun fibers with precoated carbon proceeds through diffusion‐limited shrinking core pathway while that of the as‐spun fibers follows the reaction‐limited solution precipitation mechanism. The TiC nanofibers also show superior sintering properties by increasing theoretical density of hot pressed TiB2 from 94.5% of theoretical density to 97.9% of theoretical density. When sintered with ceria, it improves the conductivity of the ceria by 18.29 times as compared to 2.94 times by TiC nanoparticles at 800 °C. The TiC nanofibers show metallic behavior as well as potential for application as electrochemical double layer capacitor supercapacitors.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91236307","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 article deals with synthesis, growth, structure, and characterization of 5‐chloro‐3‐methoxy‐4‐hydroxybenzaldehyde (5CMHBA or 5‐chlorovanillin) single crystals. A facile one‐pot method is employed for the chlorination of vanillin using N‐chlorosuccinimide. After chlorination, the single crystals of 5CMHBA are grown by slow evaporation solution growth technique. Grown crystals are subjected to single crystal X‐ray diffraction (SXRD), Fourier Transform Infrared (FTIR), and Thermogravimetric‐Differential Thermal Analysis (TG‐DTA). 5CMHBA crystallizes in the tetragonal crystal system with the space group P42/n. Vibrational characteristics are studied using FTIR. Further, thermal studies of the crystal are carried out using simultaneous TG‐DTA thermal analyzer. The molecular structure and its intermolecular interactions are studied by applying time–dependent density functional theory (TD‐DFT) using Gaussian 09 program and Hirshfeld surface analysis. A lesser energy gap of the 5CMHBA compared to that of vanillin shows the high reactivity of the molecule. Dipole moment, polarizability, and hyper‐polarizability are calculated in the molecular level and found to have greater polarizability than vanillin and also higher in order than that of standard urea molecule. This reveals the suitability of the molecule for nonlinear optical applications. The intermolecular interactions and porosity are analyzed and compared with vanillin and its polymorphs by Hirshfeld surface analysis.
{"title":"Facile Synthesis, Crystal Structure, Spectral Characterization, Quantum Chemical Calculations, and Hirshfeld Surface Analysis of 5‐Chloro‐3‐Methoxy‐4‐Hydroxybenzaldehyde","authors":"P. Nagapandiselvi","doi":"10.1002/crat.202100017","DOIUrl":"https://doi.org/10.1002/crat.202100017","url":null,"abstract":"This article deals with synthesis, growth, structure, and characterization of 5‐chloro‐3‐methoxy‐4‐hydroxybenzaldehyde (5CMHBA or 5‐chlorovanillin) single crystals. A facile one‐pot method is employed for the chlorination of vanillin using N‐chlorosuccinimide. After chlorination, the single crystals of 5CMHBA are grown by slow evaporation solution growth technique. Grown crystals are subjected to single crystal X‐ray diffraction (SXRD), Fourier Transform Infrared (FTIR), and Thermogravimetric‐Differential Thermal Analysis (TG‐DTA). 5CMHBA crystallizes in the tetragonal crystal system with the space group P42/n. Vibrational characteristics are studied using FTIR. Further, thermal studies of the crystal are carried out using simultaneous TG‐DTA thermal analyzer. The molecular structure and its intermolecular interactions are studied by applying time–dependent density functional theory (TD‐DFT) using Gaussian 09 program and Hirshfeld surface analysis. A lesser energy gap of the 5CMHBA compared to that of vanillin shows the high reactivity of the molecule. Dipole moment, polarizability, and hyper‐polarizability are calculated in the molecular level and found to have greater polarizability than vanillin and also higher in order than that of standard urea molecule. This reveals the suitability of the molecule for nonlinear optical applications. The intermolecular interactions and porosity are analyzed and compared with vanillin and its polymorphs by Hirshfeld surface analysis.","PeriodicalId":10797,"journal":{"name":"Crystal Research and Technology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73690986","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}
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