Kinetic models for crystal growth in the presence of impurities adsorbing at kinks and surface te... more Kinetic models for crystal growth in the presence of impurities adsorbing at kinks and surface terrace on the F faces of single crystals are described. Using the models general expressions relating (1) layer displacement rate and face growth rate with impurity concentration and supersaturation, and (2) supersaturation value below which growth is blocked by impurity are derived. Some typical examples of the experimental data on the growth kinetics of ionic and organic crystals and the tapering of KDP-type crystals in the presence of impurities are examined from the standpoint of the models. Analysis of the growth kinetics of various crystals reveals that different types of data are, in general, consistent with the proposed models.
This chapter contains sections titled: Types of Impurity Incorporation and the Segregation Coeffi... more This chapter contains sections titled: Types of Impurity Incorporation and the Segregation CoefficientEquilibrium Segregation CoefficientEffective Segregation CoefficientRelationship between Effective Segregation Coefficient and Face Growth RateThreshold Supersaturation for Trapping of Impurities during GrowthEffective Segregation Coefficient and Internal Stresses Caused by ImpuritiesReferencesTypes of Impurity Incorporation and the Segregation CoefficientEquilibrium Segregation CoefficientEffective Segregation CoefficientRelationship between Effective Segregation Coefficient and Face Growth RateThreshold Supersaturation for Trapping of Impurities during GrowthEffective Segregation Coefficient and Internal Stresses Caused by ImpuritiesReferences
Surface Morphology of Crystalline Solids. K Sangwal, R Rodriguez-Clemente Trans Tech Publications... more Surface Morphology of Crystalline Solids. K Sangwal, R Rodriguez-Clemente Trans Tech Publications(Switzerland), 1991,, 450, 1991. General aspects of various types of the surface morphology of crystalline solids in the form ...
The Vickers microhardness of the (100) and (001) planes of SrLaAlO4 and SrLaGaO4 single crystals ... more The Vickers microhardness of the (100) and (001) planes of SrLaAlO4 and SrLaGaO4 single crystals was investigated using a PMT-3 hardness tester up to an applied load of 100 g. It was observed that, up to an applied load of 50 g, the hardness of the crystals increases with an increase in load and thereafter it is practically independent of the indentation load. The experimental data were analysed using Hays-Kendall and Li-Bradt models to obtain load- independent hardness of the crystals. The results showed that: (1) for crystals of a particular orientation, the load-independent hardness obtained by Li-Bradt model is higher by a factor of about 4/3 than that predicted by Hays-Kendall model, (2) the load-independent hardness of the (100) plane is higher than that of the (001) plane for both SLA and SLG crystals, but the hardness anisotropy is more pronounced in SLA than SLG crystals, and (3) the load- independent hardness of a sample of a particular orientation practically does not dep...
The monograph gives a generalized description of the mechanical properties of different solids, b... more The monograph gives a generalized description of the mechanical properties of different solids, both crystalline (single crystals and nanocrystals) and noncrystalline (amorphous metallic alloys, polymers and glasses).
Results of a study of silica and silica–titania sol–gel coatings for the creation of intermediate... more Results of a study of silica and silica–titania sol–gel coatings for the creation of intermediate interfaces between commercially pure Ti or titanium alloy Ti6Al4VELI and dental porcelain are presented. Coatings of SiO2 on Ti6Al4V alloy and SiO2–TiO2 on Ti were deposited using sol–gel method. Surface microstructures and wear behaviour of the coatings were studied by using scanning electron microscopy with electron diffraction spectroscopy and pin-on-disc method. It is found that (1) Ti6Al4V/SiO2 and Ti/SiO2–TiO2 coatings obtained by the sol–gel method are compact, chemically homogeneous and relatively rough, and (2) the smaller wear of SiO2 coatings than that of SiO2–TiO2 coatings is associated with differences in their microstructure and roughness.
Fats and oils are complex systems composed primarily of mixtures of distinct triglycerides, which... more Fats and oils are complex systems composed primarily of mixtures of distinct triglycerides, which are esters of one mole of glycerol and three moles of fatty acids. Different fats and oils contain different proportions of chemically distinct triglycerides varying in carbon chain length and melting point. Therefore, instead of melting at a single temperature, a fat melts over a wide range of temperature and high melting-point glycerides are soluble in lower melting-point glycerides. Consequently, the crystallization behavior of molten fats and oils is relatively complex in comparison with that of simple one-component systems. An additional difficulty associated with the crystallization of mixtures of triglycerides is the existence of different polymorphs of triglycerides. In this chapter the nucleation and crystallization behavior of fats and oils is presented and discussed. The discussion is confined to single-component systems, although fats and oils are composed of a major compone...
Using the model of the formation of ionic clusters, an analytical equation valid for the equilibr... more Using the model of the formation of ionic clusters, an analytical equation valid for the equilibrium concentration of solute in the solution is derived. Employing Boltzmann statistics in conjunction with the experimental values of the equilibrium concentration of KF, KCl, KBr and KI electrolytes in aqueous solution at 25°C, the above analytical equation is used to compute the best values of the dielectric permittivity of the solvation shell for the K+ ion and four anions separately. These values of the dielectric permittivity of the solvation shells are then used to compute adsorption energy of water molecules on the {100} surface of regular clusters and their surface tension in the solution as functions of type of the salt, its concentration and cluster size. It is found that both the average adsorption energy and the interfacial tension of regular clusters composed of i ions can be approximated by a linear function of i−12 for different concentrations of all the investigated potas...
Kinetic models for crystal growth in the presence of impurities adsorbing at kinks and surface te... more Kinetic models for crystal growth in the presence of impurities adsorbing at kinks and surface terrace on the F faces of single crystals are described. Using the models general expressions relating (1) layer displacement rate and face growth rate with impurity concentration and supersaturation, and (2) supersaturation value below which growth is blocked by impurity are derived. Some typical examples of the experimental data on the growth kinetics of ionic and organic crystals and the tapering of KDP-type crystals in the presence of impurities are examined from the standpoint of the models. Analysis of the growth kinetics of various crystals reveals that different types of data are, in general, consistent with the proposed models.
This chapter contains sections titled: Types of Impurity Incorporation and the Segregation Coeffi... more This chapter contains sections titled: Types of Impurity Incorporation and the Segregation CoefficientEquilibrium Segregation CoefficientEffective Segregation CoefficientRelationship between Effective Segregation Coefficient and Face Growth RateThreshold Supersaturation for Trapping of Impurities during GrowthEffective Segregation Coefficient and Internal Stresses Caused by ImpuritiesReferencesTypes of Impurity Incorporation and the Segregation CoefficientEquilibrium Segregation CoefficientEffective Segregation CoefficientRelationship between Effective Segregation Coefficient and Face Growth RateThreshold Supersaturation for Trapping of Impurities during GrowthEffective Segregation Coefficient and Internal Stresses Caused by ImpuritiesReferences
Surface Morphology of Crystalline Solids. K Sangwal, R Rodriguez-Clemente Trans Tech Publications... more Surface Morphology of Crystalline Solids. K Sangwal, R Rodriguez-Clemente Trans Tech Publications(Switzerland), 1991,, 450, 1991. General aspects of various types of the surface morphology of crystalline solids in the form ...
The Vickers microhardness of the (100) and (001) planes of SrLaAlO4 and SrLaGaO4 single crystals ... more The Vickers microhardness of the (100) and (001) planes of SrLaAlO4 and SrLaGaO4 single crystals was investigated using a PMT-3 hardness tester up to an applied load of 100 g. It was observed that, up to an applied load of 50 g, the hardness of the crystals increases with an increase in load and thereafter it is practically independent of the indentation load. The experimental data were analysed using Hays-Kendall and Li-Bradt models to obtain load- independent hardness of the crystals. The results showed that: (1) for crystals of a particular orientation, the load-independent hardness obtained by Li-Bradt model is higher by a factor of about 4/3 than that predicted by Hays-Kendall model, (2) the load-independent hardness of the (100) plane is higher than that of the (001) plane for both SLA and SLG crystals, but the hardness anisotropy is more pronounced in SLA than SLG crystals, and (3) the load- independent hardness of a sample of a particular orientation practically does not dep...
The monograph gives a generalized description of the mechanical properties of different solids, b... more The monograph gives a generalized description of the mechanical properties of different solids, both crystalline (single crystals and nanocrystals) and noncrystalline (amorphous metallic alloys, polymers and glasses).
Results of a study of silica and silica–titania sol–gel coatings for the creation of intermediate... more Results of a study of silica and silica–titania sol–gel coatings for the creation of intermediate interfaces between commercially pure Ti or titanium alloy Ti6Al4VELI and dental porcelain are presented. Coatings of SiO2 on Ti6Al4V alloy and SiO2–TiO2 on Ti were deposited using sol–gel method. Surface microstructures and wear behaviour of the coatings were studied by using scanning electron microscopy with electron diffraction spectroscopy and pin-on-disc method. It is found that (1) Ti6Al4V/SiO2 and Ti/SiO2–TiO2 coatings obtained by the sol–gel method are compact, chemically homogeneous and relatively rough, and (2) the smaller wear of SiO2 coatings than that of SiO2–TiO2 coatings is associated with differences in their microstructure and roughness.
Fats and oils are complex systems composed primarily of mixtures of distinct triglycerides, which... more Fats and oils are complex systems composed primarily of mixtures of distinct triglycerides, which are esters of one mole of glycerol and three moles of fatty acids. Different fats and oils contain different proportions of chemically distinct triglycerides varying in carbon chain length and melting point. Therefore, instead of melting at a single temperature, a fat melts over a wide range of temperature and high melting-point glycerides are soluble in lower melting-point glycerides. Consequently, the crystallization behavior of molten fats and oils is relatively complex in comparison with that of simple one-component systems. An additional difficulty associated with the crystallization of mixtures of triglycerides is the existence of different polymorphs of triglycerides. In this chapter the nucleation and crystallization behavior of fats and oils is presented and discussed. The discussion is confined to single-component systems, although fats and oils are composed of a major compone...
Using the model of the formation of ionic clusters, an analytical equation valid for the equilibr... more Using the model of the formation of ionic clusters, an analytical equation valid for the equilibrium concentration of solute in the solution is derived. Employing Boltzmann statistics in conjunction with the experimental values of the equilibrium concentration of KF, KCl, KBr and KI electrolytes in aqueous solution at 25°C, the above analytical equation is used to compute the best values of the dielectric permittivity of the solvation shell for the K+ ion and four anions separately. These values of the dielectric permittivity of the solvation shells are then used to compute adsorption energy of water molecules on the {100} surface of regular clusters and their surface tension in the solution as functions of type of the salt, its concentration and cluster size. It is found that both the average adsorption energy and the interfacial tension of regular clusters composed of i ions can be approximated by a linear function of i−12 for different concentrations of all the investigated potas...
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