- Dr. Chandkiram Gautam, now is a senior Assistant Professor of Physics, He got his B Sc in Science (Physics, Chemistry... moreDr. Chandkiram Gautam, now is a senior Assistant Professor of Physics, He got his B Sc in Science (Physics, Chemistry, Math), M Sc in Physics (Electronics), degree from C.C.S. University, Meerut in 1995 and 1997 respectively. Dr. Gautam received his M Phil degree in Physics (Instrumentation) from IIT Roorkee (Formely University of Roorkee, Roorkee) India. He is M. Tech. in Materials Technology in 2000 and received Ph.D. degree in Ceramic Engineering in 2005 from Institute of Technology, Banaras Hindu University, Varanasi, India. Recently he got the Raman Post Doctoral Research Award (2014-2015) at Department of Nano Engineering and Materials Science, Rice University, Houston Texas, USA. He is also awarded UGC Research Award Fellowship during 2012-2013. Dr. Gautam is also a recipient of ‘Young Scientist’ Award from UPCST, Lucknow (2007). Currently Dr. Gautam is working in the research area of glass and glass ceramics doped with CNT and Zirconia for Dental and bone Restoration Applications. Nano synthesis of layered materials for effective cleaning of water, humidity and gas sensor applications. Dr. Gautam having various life time memberships such as MRSI, India, Indian Ceramic Society, Indian Physics Association (IPA), American Chemical Society and also having the membership of editorial board of several reputed journals. He has published more than 63 research papers in National/International journals.edit
- Prof. Devendra Kumar, Department of Ceramic Engineering, Indian Institute of Technology, Banaras Hindu university Varanasi-221005 (India), Prof. P. M. Ajayan, Depart of Materials Science and Nano-Engineering, Rice University, Houston Texas, USA, Prof. Om Parkash, Department of Ceramic Engineering, Indian Institute of Technology, Banaras Hindu university Varanasi-221005 (India)edit
Abstract Bulk transparent barium strontium titanate borosilicate glasses in glass system (65-x)[(Ba0.6Sr0.4).TiO3]-30[2SiO2.B2O3]-5[K2O]-x[A2O3], A = La, Fe (x = 2, 5 and 10) were prepared by rapid melt-quench technique and subsequently,... more
Abstract Bulk transparent barium strontium titanate borosilicate glasses in glass system (65-x)[(Ba0.6Sr0.4).TiO3]-30[2SiO2.B2O3]-5[K2O]-x[A2O3], A = La, Fe (x = 2, 5 and 10) were prepared by rapid melt-quench technique and subsequently, converted into glass ceramics by regulated heat treatment process. The phase identification was carried out by X-ray powder diffraction and their surface morphology was studied by scanning electron microscopy. The dielectric properties were studied by impedance spectroscopic technique. Investigated glass samples were crystallized into major and secondary phases of Ba1.91Sr0.09TiO4 and Ba2TiSi2O8, respectively. A very high dielectric constant having value upto 68000 was found in glass ceramic sample BST5K10F. This high value of dielectric constant was attributed to interfacial polarization, which arose due to conductivity difference among semiconducting crystalline phases, conducting grains and insulating grain boundaries. Donor dopant La2O3 and acceptor dopant Fe2O3 play an important role for enhancing crystallization, dielectric constant and retardation of dielectric loss in the samples. Moreover, higher value of dielectric constant and lower value of dielectric loss was found in Fe2O3 doped samples in comparison to La2O3 doped samples.
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Hydroxyapatite (HAp) nano-ceramic powder was synthesized successfully via microwave irradiation technique.
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Lithium cobalt fluorophosphate, Li(2)CoPO(4)F, is successfully synthesized by a solid state reaction under Ar flow at 700 °C. X-ray diffraction and scanning electron microscopic studies are utilized to analyze the structural and... more
Lithium cobalt fluorophosphate, Li(2)CoPO(4)F, is successfully synthesized by a solid state reaction under Ar flow at 700 °C. X-ray diffraction and scanning electron microscopic studies are utilized to analyze the structural and morphological features of the synthesized materials, respectively. The presence of fluorine is also supported by energy-dispersive X-ray spectroscopy. The electrochemical properties are evaluated by means of Li/Li(2)CoPO(4)F half-cell configurations in both potentiostatic and galvanostatic modes. The Li/Li(2)CoPO(4)F cell delivers an initial discharge capacity of 132 mA h g(-1) at a current density of 0.1 mA cm(-2) between 2.0 and 5.1 V at room temperature. Due to the higher operating potential of the Co(2+/3+) couple in the fluorophosphate matrix, this cell shows a capacity retention of only 53% after 20 cycles, still the material delivered 108 mA h g(-1) at a high current rate of 1 C. Cyclic voltammetric studies corroborate the insertion and extraction of Li(+) ions by a single phase reaction mechanism during cycling.
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We fabricated three-dimensional photonic crystals by self-assembling gold nanoshells via forced sedimentation method. Gold nanoshells with a diameter of 458 nm (418-nm silica core and 20-nm gold shell) were synthesized and self-assembled... more
We fabricated three-dimensional photonic crystals by self-assembling gold nanoshells via forced sedimentation method. Gold nanoshells with a diameter of 458 nm (418-nm silica core and 20-nm gold shell) were synthesized and self-assembled into a 5-μm-thick opal structure. We observed reflection peaks at 710 and 1240 nm, which are believed to be from the complete three-dimensional photonic band gap and the (111) directional gap, respectively. Theses results were in good agreement with the photonic band-structure calculations done by the finite-difference time-domain method. Angle-resolved reflectivity measurements were also performed to investigate the existence of the complete three-dimensional photonic band gap.
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Synthesis methods for the exfoliation of BNNSs and BNNS functionalization methods are reviewed.
Research Interests: Materials Science and RSC
Abstract Hydroxyapatite is a multifunctional biomaterial that combines biocompatibility and bioactivity for various biomedical applications such as bone repairing and bioimaging. In the present study nano-hydroxyapatite (n-HAp) was... more
Abstract Hydroxyapatite is a multifunctional biomaterial that combines biocompatibility and bioactivity for various biomedical applications such as bone repairing and bioimaging. In the present study nano-hydroxyapatite (n-HAp) was synthesized using microwave irradiation technique. Subsequently, the MgO was introduced into the n-HAp matrix and various bioactive compositions of HAp-MgO nanocomposites were fabricated. The structural, mechanical, in vivo cell viability, and in vivo imaging properties of these nanocomposites were studied. The XRD results show that the composites sintered at 1200 °C, n-HAp partially decomposed into beta-tricalcium phosphate (β-TCP). The sintered density of the composites varying from 2.72 ± 0.066 to 3.03 ± 0.093 g cm−3 with the addition of 0.0–2.0 wt % of MgO. As increasing the amounts of MgO, a remarkable increase in the mechanical properties of the composite was achieved. The composite HAp-1.0MgO exhibited the highest mechanical properties with a compressive strength of 111.20 ± 5 MPa, fracture toughness 136.98 ± 5 MJ/m3 and revealed much amplification than pure n-HAp. Thus, the addition of MgO acting as an excellent mechanical reinforcing agent. The surface morphology of the composites revealed a significant change in the porous surface to denser. The low contact angle revealed the considerable hydrophilic nature of the composite surface. The biological study of these nano-composites with Drosophila third instar larvae indicated comparable or more favorable biocompatibility in terms of cell viability. Also internalized by Drosophila third instar larvae exhibited fluorescence under green and red filters using epifluorescence microscopy. Thus, the fabricated HAp-MgO nanocomposites with excellent biological properties are expected to be a multifunctional bioactive material for bone tissue regeneration and cell imaging applications.
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In this study, six compositions in the system [x(h-BN)–(100 − x)ZrO2], (10 ≤ x ≤ 90) were synthesized by a bottom up approach, i.e., the solid-state reaction technique.
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Research Interests: Biochemistry, Genetics, Physiology, Biophysics, Hematology, and 14 moreBiotechnology, Cell Biology, Space Science, Medicine, SEM, TEM, XRD, Sample, MTT, UTM, Mj, American Chemical Society, HAP, and GNP
Various glass samples in the compound 55[(PbxCa1−x)O⋅TiO2]-44[2SiO2⋅B2O3]-1Ge (0 ≤ x ≤ 0.7) were fabricated by using the melt-quenching technique and their glass ceramics (GC) were obtained by controlled crystallization of the glass... more
Various glass samples in the compound 55[(PbxCa1−x)O⋅TiO2]-44[2SiO2⋅B2O3]-1Ge (0 ≤ x ≤ 0.7) were fabricated by using the melt-quenching technique and their glass ceramics (GC) were obtained by controlled crystallization of the glass samples. The identification of phase and crystal structure with measurement of cell parameters was carried out using X-ray diffractometer (XRD). XRD results revealed the presence of the single phase formation of rutile (TiO2). The surface morphology of the synthesized GC samples was evaluated using a scanning electron microscope (SEM). The electrical behaviour of three selected GC samples with x = 0.0, 0.3 and 0.7 was being widely studied using impedance and immittance spectroscopy. The lead free GC sample, x = 0.0 possesses a high dielectric constant, 91,252 at low frequency (50 Hz) and high temperature (500 °C) due to space charge polarization that was ascertained by impedance spectroscopy of the tested samples. The fitting of impedance spectra with a modelled equivalent circuit was performed and different values of resistance and capacitance were calculated.
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Abstract Various compositions (0.0 ≤ x ≤ 1.0) in the glassy system 55[(PbxBi1-x)TiO3]-44[2SiO2.B2O3] doped with one mol percent of graphene nanoplatlets (GNPs) have been synthesized using the conventional melt-quenching technique. X-ray... more
Abstract Various compositions (0.0 ≤ x ≤ 1.0) in the glassy system 55[(PbxBi1-x)TiO3]-44[2SiO2.B2O3] doped with one mol percent of graphene nanoplatlets (GNPs) have been synthesized using the conventional melt-quenching technique. X-ray diffraction (XRD) study revealed the formation of bulk and transparent lead bismuth titanate borosilicate glasses. Density and molar volume were determined using the liquid displacement method. Structural analyses were carried out in detail using different characterization techniques such as infrared spectroscopy, Raman spectroscopy, UV–vis spectroscopy and solid state nuclear magnetic resonance (SSNMR) spectroscopy. 29Si and 11B-MAS-NMR-spectral analysis for five glass samples with different fraction of PbO reveal that as increases the content of PbO, the silicate and borate network become more polymerized.
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Abstract The present investigation mainly focused on hexagonal boron nitride (h-BN) substitution for modified physical, mechanical and biological properties of nano zirconia (nZrO2).A simple and scalable solid-state reaction method has... more
Abstract The present investigation mainly focused on hexagonal boron nitride (h-BN) substitution for modified physical, mechanical and biological properties of nano zirconia (nZrO2).A simple and scalable solid-state reaction method has been used to prepare a three dimensional (3-D) composites in the system [(15+x)BN-(85-x)ZrO2] (0 ≤x ≤ 55). A major novel phase of zirconium oxynitrate, ZrO(NO3)2 was confirmed by X-ray diffraction(XRD) results. The uniform and interconnected distribution of large h-BN nanosheets ensure the significant grain refinement of nZrO2 established by surface morphology study of fabricated composites. This reinforcement of h-BN plays a pivotal role to enhance the ductility of zirconia. The composite sample 70B-30Z has a remarkable mechanical strength and less wear resistance as compared to the natural bone, for this sample (70B-30Z) various mechanical parameters i.e. Young’s modulus, fracture toughness, maximum mechanical strength, and density are found to be 9.84 MPa, 4.12 MPa m1/2, 174.94 MPa, and 2.54 g cm−3 respectively. The noteworthy cell proliferation at 25 µg/ml by MTT assay for the composite 70B-30Z recognizes it as a suitable bone implant material.
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Abstract In this study, the melt-quenching technique was used to synthesize various glass compositions for the system 55[(PbxCa1-x)·OTiO2]-44[2SiO2·B2O3]-1V2O5 (0.0 ≤ x ≤ 0.7). The synthesized glasses were investigated by X-ray... more
Abstract In this study, the melt-quenching technique was used to synthesize various glass compositions for the system 55[(PbxCa1-x)·OTiO2]-44[2SiO2·B2O3]-1V2O5 (0.0 ≤ x ≤ 0.7). The synthesized glasses were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, ultraviolet–visible spectroscopy, scanning electron microscopy (SEM), and nuclear magnetic resonance spectroscopy (NMR). The experimental density of the glass samples increased from 1.48 to 2.19 g/cm3 as the concentration of lead oxide (PbO) increased. The XRD results agreed well with the SEM observations and they confirmed the amorphous nature of the glasses. The FTIR and Raman analyses indicated the presence of various bonds comprising V O V, Pb O B, B O B, Si O Si, B O Si and B OH, which were attributed to different vibrations. The optical band gap values decreased from 2.07 to 1.65 eV as the PbO content increased. 29Si and 11B magic angle spinning solid state NMR spectral analysis suggested that the number of non-bridging oxygens increased within the silicate and borate network as the concentration of PbO increased in the glassy system.
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Recent advances and demands in biomedical applications drive a large amount of research to synthesize easily scalable low-density, high-strength, and wear-resistant biomaterials. The chemical inertness with low density combined with high... more
Recent advances and demands in biomedical applications drive a large amount of research to synthesize easily scalable low-density, high-strength, and wear-resistant biomaterials. The chemical inertness with low density combined with high strength makes h-BN one of the promising materials for such application. In this work, three-dimensional hexagonal boron nitride (h-BN) interconnected with boron trioxide (BO) was prepared by easily scalable and energy efficient spark plasma sintering (SPS) process. The composite structure shows significant densification (1.6-1.9 g/cm) and high surface area (0.97-14.5 m/g) at an extremely low SPS temperature of 250 °C. A high compressive strength of 291 MPa with a reasonably good wear resistance was obtained for the composite structure. The formation of strong covalent bonds between h-BN and BO was formulated and established by molecular dynamics simulation. The composite showed significant effect on cell viability/proliferation. It shows a high min...
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Abstract In the present study, pure hydroxyapatite (HAp) nano powder was prepared successfully via microwave irradiation method. To enhance the mechanical properties of pure HAp, La 2 O 3 was taken as an additive. HAp composites were... more
Abstract In the present study, pure hydroxyapatite (HAp) nano powder was prepared successfully via microwave irradiation method. To enhance the mechanical properties of pure HAp, La 2 O 3 was taken as an additive. HAp composites were synthesized with addition of different concentrations of La 2 O 3 (0.1, 0.2, 0.3 and 0.5 wt%) by conventional solid state route. The HAp-La 2 O 3 powders were sintered at 1200 °C for 3 h. On the basis of XRD results, formation of HAp-La 2 O 3 was confirmed. The surface morphology of the composite samples was studied by scanning electron microscopy (SEM). Transmission electron microscopy (TEM) confirmed the presence of tiny particles of La 2 O 3 in the HAp matrix with adequate porosity. The mechanical properties of the pure HAp and its composites were determined by universal testing machine (UTM). The 0.5 wt% of HAp-La 2 O 3 sample exhibited the highest density, 2.85 g/cm 3 and mechanical strength ~ 108.89 MPa. The calculated values of Young's modulus, fracture toughness and load bearing capability are 90.75 GPa, 130.06 MJ/m 3 and ~ 3.85 kN respectively. It was observed that the addition of La 2 O 3 significantly improved the mechanical properties of HAp. To see the cytotoxicity effect on HAp-La 2 O 3 composites (0.1 and 0.5 wt%), MTT assay were performed using osteoblast cells.
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Zirconia (ZrO2) based dental ceramics have been considered to be advantageous materials with adequate mechanical properties for the manufacturing of medical devices.
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A stable, conductive, additive-free and scalable 3D architecture supercapacitor electrode fabricated by atomically thin 2D sheets of GO and MoS2 shows superior electrochemical properties which are further substantiated using MD simulations.
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3D (three dimensional) architectures synthesised using an easily scalable solid state method which results in an interconnected network of porous h-BN sheets with boron trioxide are reported in this study.
Research Interests: Nanomaterials and RSC
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Lead bismuth titanate ceramics were prepared using solid-state method. The structural and dielectric behaviors were studied using X-ray diffraction, scanning electron microscopy, and LCR meter. X-ray diffraction studies showed that... more
Lead bismuth titanate ceramics were prepared using solid-state method. The structural and dielectric behaviors were studied using X-ray diffraction, scanning electron microscopy, and LCR meter. X-ray diffraction studies showed that crystal structure changed with changing compositions and sintering temperatures. The value of dielectric constant was found to be more for lead-free samples with the addition of 1 mol% Fe2O3 rather than CrO3-doped samples. Activation energy, Ea, was determined from the slope of log τ versus 1000/T plots for ceramic samples 3P7BT1C800 and 3P7BT1C900. Impedance spectroscopy revealed that resistance decreases with increasing temperature.
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ABSTRACT Publication details, including instructions for authors and subscription information: Various barium strontium titanate borosilicate glasses were prepared by a rapid melt-quench technique. Spectroscopic studies have been carried... more
ABSTRACT Publication details, including instructions for authors and subscription information: Various barium strontium titanate borosilicate glasses were prepared by a rapid melt-quench technique. Spectroscopic studies have been carried out on investigated glasses for their structural information. Infrared and Raman spectroscopic studies showed that these glasses are formed by glass-forming network of borate and silicate as well as network modifiers in the form of cations of alkaline earth atoms. The borate and silicate networks are modified by barium, strontium, titanium, and iron cations in glass matrix. The network of triborate unit is modified in tetraborate unit by adding ferric oxide in a glassy matrix. The optical studies are performed by ultraviolet-visible spectroscopy and it confirms that the band gap decreases with increase in the concentration of ferric oxide.
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Ferroelectric (PbxSr1−x)TiO3 (PST) perovskite phase has been crystallized in borosilicate glassy matrix with a suitable choice of composition and heat treatment schedule. La2O3 is a donor dopant for PST and can make it semiconducting.... more
Ferroelectric (PbxSr1−x)TiO3 (PST) perovskite phase has been crystallized in borosilicate glassy matrix with a suitable choice of composition and heat treatment schedule. La2O3 is a donor dopant for PST and can make it semiconducting. Dispersion of semiconducting perovskite phase in insulating glassy matrix in glass-ceramic samples may lead to the formation of space charge polarization around crystal-glass interface, leading to a high value of effective dielectric constant, εr. Therefore, with the aim of the developing glass ceramics with high dielectric constant, glasses in the system 64[(PbxSr1−x)O·TiO2]-25[2SiO2·B2O3]-5[K2O]-5[BaO]-1[La2O3] have been prepared (0.5≤x≤1). It is found that the addition of La2O3 strongly affected the crystallization and dielectric behavior of glass-ceramic with PST perovskite phase. All glass ceramic samples show a diffuse broad Curie peak in their εr versus T plots. Curie peak temperature, Tc, depends on compositions of the glass-ceramic samples as ...
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We are reporting synthesis and structural and optical investigation of strontium bismuth titanate borosilicate glasses with addition of one mole percent cerium oxide (CeO2). Glasses were synthesized by conventional rapid melt quench... more
We are reporting synthesis and structural and optical investigation of strontium bismuth titanate borosilicate glasses with addition of one mole percent cerium oxide (CeO2). Glasses were synthesized by conventional rapid melt quench method. XRD studies of the glass samples confirm the amorphous nature. Infrared absorption spectra various strontium bismuth titanate borosilicate glass samples having glass system 60[(Sr1-xBix)TiO3]-39[2SiO2B2O3]-1[CeO2] (x=0.0,0.1,0.2,0.4) were recorded over a continuous spectral range from 400 to 4000 cm−1. IR spectra were analyzed to determine and differentiate of various vibrational modes in the structural change. Raman spectroscopy of all glass samples was also carried out in the wave number range from 200 to 2000 cm−1.
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Borate glasses are the technologically important class of glasses and play a significant role in various applications. Borate glasses contain planar BO3groups as structural units, rather than tetrahedral SiO4groups. The oxygen atoms are,... more
Borate glasses are the technologically important class of glasses and play a significant role in various applications. Borate glasses contain planar BO3groups as structural units, rather than tetrahedral SiO4groups. The oxygen atoms are, as in SiO2, again connected to two network-forming atoms, in case of boron. The radial distribution analysis describes the B2O3glass structure as consisting of boroxol rings, that is, planar rings containing three boron atoms and three oxygen atoms. The network forming of the B2O3and the SiO4is affected with the addition of some metal cation additives Pb, Zn, Cd, and so forth. These additives also work as a network modifier and a nucleating agent for crystallization of glass. Therefore, the optical properties of the borate glasses have been changed significantly.
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A new series of lead bismuth titanate borosilicate glasses with addition of one percent lanthanum oxide have been synthesized using melt-quench technique. X-ray diffraction patterns have been recorded to confirm the amorphous nature of... more
A new series of lead bismuth titanate borosilicate glasses with addition of one percent lanthanum oxide have been synthesized using melt-quench technique. X-ray diffraction patterns have been recorded to confirm the amorphous nature of the prepared glass samples. The synthesized glasses have been characterized by using various spectroscopic techniques such as UV-visible, infrared, and Raman spectroscopy. UV-visible measurements were recorded in the wavelength range from 200 to 1100 nm whereas IR and Raman spectroscopic measurements were recorded over a continuous wavenumber range from 400 to 5000 cm−1 and 1000 to 2000 cm−1 respectively. The different absorption peaks/bands were formed in IR spectral patterns. The spectral bands appear towards the lower wavenumber sides due to the Bi and Pb, content while the bands appear towards the higher wavenumber sides due to the formation of diborate and triborate network units.
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ABSTRACT Various glass samples were prepared by melt quench technique in the glass system [(Ba1�xSrx) TiO3]–[2SiO2–B2O3]–[K2O] doped with 1 mole% of La2O3. Infrared spectra show the number of absorption peaks with different spliting in... more
ABSTRACT Various glass samples were prepared by melt quench technique in the glass system [(Ba1�xSrx) TiO3]–[2SiO2–B2O3]–[K2O] doped with 1 mole% of La2O3. Infrared spectra show the number of absorption peaks with different spliting in the wave number range from 450 to 4000 cm �1 . Absorption peaks occurs due to asymetric vibrational streching of borate by relaxation of the bond B–O of trigonal BO3. Raman pectra show the Raman bands due to ring-type metaborate anions, symmetric breathing vibrations BO3 triangles replaced by BO4 tetrahedra, and symmetric breathing vibrations of six-member rings. The differential thermal analysis of a glass sample corresponding to compositionx¼0.0 shows crystallization temperature at 847 C and glass transition temperature at 688 C. X-ray diffraction (XRD) pattern of glass ceramic samples shows the major crystalline phase of BaTiO3whereas pyrochlore phases of barium titanium silicate. Scanning electron micrographs confirm the results of XRD as barium titanate is major crystalline phase along with pyrochlore phase of barium titanium silicate.
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ABSTRACT Various glass samples, of glass system [(Ba12xSrx)TiO3]–[2SiO2–B2O3]–K2O with addition of La2O3, were prepared by melt quenched method. Differential thermal analysis of glass samples was carried out in the temperature range of... more
ABSTRACT Various glass samples, of glass system [(Ba12xSrx)TiO3]–[2SiO2–B2O3]–K2O with addition of La2O3, were prepared by melt quenched method. Differential thermal analysis of glass samples was carried out in the temperature range of 100–1200uC in order to study the kinetics of crystallisation behaviour. Glass samples were subjected to appropriate heat treatment schedules for their suitable crystallisation from glass to glass ceramics. X-ray diffraction analysis of glass ceramic samples indicated the presence of major crystalline phase of BaTiO3 along with some secondary phases of Ba2TiSi2O8 and Ba2Ti2B2O9. Scanning electron microscopy measurements were also performed to see the morphology of crystallites of the major/secondary phase formation in the glass ceramic samples. We found that La2O3 played an important role to increase nucleation and growth of the crystallites in the glassy matrix.
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Lead bismuth titanate borosilicate glasses were prepared in the glass system 65[(PbxBi1-x)·TiO3]-34[2SiO2·B2O3]-1La2O3 (0.0≤x≤1.0) doped with one mole percent of La2O3 via conventional melt quench method. The amorphous nature of glass... more
Lead bismuth titanate borosilicate glasses were prepared in the glass system 65[(PbxBi1-x)·TiO3]-34[2SiO2·B2O3]-1La2O3 (0.0≤x≤1.0) doped with one mole percent of La2O3 via conventional melt quench method. The amorphous nature of glass samples in this glass system is confirmed by using X-ray diffraction (XRD) study. Differential thermal analysis (DTA) has been employed to determine the glass transition temperature, Tg, as well as crystallization temperature, Tc. DTA measurements were recorded in temperature range from 30 to 1200°C. The prepared glasses were crystallized by regulated controlled heat treatment process on the basis of their DTA results. These samples are carried out for XRD measurements in the 2θ range from 20 to 80° to study the crystallization behaviour and phase formation of the glass ceramic samples. The scanning electron microscopy (SEM) of these glass ceramic samples has been carried out to explore the morphology through nucleation and growth of the crystallites i...
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3D (three dimensional) architectures synthesised using an easily scalable solid state method which results in an interconnected network of porous h-BN sheets with boron trioxide are reported in this study. The boron trioxide acts as a... more
3D (three dimensional) architectures synthesised using an easily scalable solid state method which results in an interconnected network of porous h-BN sheets with boron trioxide are reported in this study. The boron trioxide acts as a nucleating agent for the formation of laterally large nanosheets of h-BN with a low density and increases the specific surface area. The stable form shows improved mechanical properties (experimentally and using MD simulation) and serves as a suitable material for humidity and liquefied petroleum gas (LPG) sensor applications. The sensor shows stability for up to several months without losing its sensitivity.
Research Interests: Nanomaterials and RSC
Various lead strontium titanate borosilicate glass samples were prepared with addition of 1 mol % of chromium trioxide and graphene nanoplatelets by convention melt quench method. Their structural and optical behaviors were studied by... more
Various lead strontium titanate borosilicate glass samples were prepared with addition of 1 mol % of chromium trioxide and graphene nanoplatelets by convention melt quench method. Their structural and optical behaviors were studied by infrared spectroscopy, ultraviolet–visible spectroscopy, and scanning electron microscopy. The infrared spectroscopic studies were carried in the wavenumber range of 400–4000 cm−1. The energy band gap of bulk transparent glass samples were found by Tauc plots of ultraviolet–visible spectra. Surface morphological studied was done by scanning electron microscopy. The density of these prepared lead strontium titanate borosilicate glass samples were calculated by “Archimedes principle” of liquid displacement method.
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The purposes of this studywas to detect S. mutans and S. sobrinus from Dental Plaques adhered on Zirconia, PFM and NiCr crown by RT-PCR amplification. Supragingival and the subgingival plaque was taken from the crown site of the 118... more
The purposes of this studywas to detect S. mutans and S. sobrinus from Dental Plaques adhered on Zirconia, PFM and NiCr crown by RT-PCR amplification. Supragingival and the subgingival plaque was taken from the crown site of the 118 participants from all the three groups who had crown restoration and were categorized as Group I (Zirconia) (27 cases), Group II(PFM) (49 cases) and Group III(Ni-Cr) (42 case), respectively by using sterile curettes (Gracey Curettes). The PCR amplified products were subjected to electrophoresis in agarose gel and visualized on a UV transilluminator. Patient’s (118) age ranged between 18 to 40 years divided into the three groups who had crown restoration and were categorized as Group I (Zirconia) (27 cases), Group II(PFM) (49 cases) and Group III(Ni-Cr) (42 case), respectively. The S. mutans and S. sobrinuswas found to be present in 60.2% and 44.9 % of cases respectively. In the present study, S. sobrinus alone was present only in 35.6% of cases. A signif...
Various glass composition, x = 0.0, 0.2, 0.4 and 0.6 were synthesized in a bulky glass system 64 [(Pb1-xSrx)OTiO2]-25 [(2SiO2·B2O3)]-[3BaO·7K2O]-1La2O3 using melt-quenching technique. All synthesized glasses were converted into their... more
Various glass composition, x = 0.0, 0.2, 0.4 and 0.6 were synthesized in a bulky glass system 64 [(Pb1-xSrx)OTiO2]-25 [(2SiO2·B2O3)]-[3BaO·7K2O]-1La2O3 using melt-quenching technique. All synthesized glasses were converted into their glass ceramics via a scalable solid-state reaction method. Several physical parameters were investigated such as green/sintered density, oxygen packing density, ionic concentrations, molar volume, and molar mass respectively. For phase identification of the sintered glass ceramics, X-Ray diffraction measurements were performed. Further, to evaluate structural properties of the sintered glass ceramic samples, FTIR spectroscopy was also performed. To reveal the grain/grain boundaries and elemental analysis, surface morphology of the sintered glass ceramics followed by energy dispersive X-ray analysis was evaluated by employing a scanning electron microscopic technique. Further, to study the mechanical properties of these glass ceramics, tribological tests...
The main objective of present work was to synthesize sodium doped polycrystalline hydroxyapatite NaHAp (NaOH-HAp) powder by employing wet chemical precipitation method and its composites with alumina (Al2O3; 0, 10, 40, 70 wt%) using a... more
The main objective of present work was to synthesize sodium doped polycrystalline hydroxyapatite NaHAp (NaOH-HAp) powder by employing wet chemical precipitation method and its composites with alumina (Al2O3; 0, 10, 40, 70 wt%) using a scalable solid-state reaction method. Detailed investigations of NaHAp and its composites using X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, UV–visible spectroscopy, scanning electron microscopy followed by energy-dispersive X-ray spectroscopy and sensing behaviour is carefully described. XRD results exhibited major and minor phase of HAp, Ca2P2O7 and NaOH for NaHAp sample while for all fabricated composites of HAp–NaOH–Al2O3 and revealed the major phase of hibonite CaO(Al2O3)6 along with secondary phases of Ca2P2O7, Na4[Al(PO4)2(OH)], Na3Al(OH)(HPO4)(PO4), NaAl3(PO4)2(OH)4 and NaOH. The crystallite size of NaHAp-based composites was also determined and lies in the range of 200–2800 nm, which is la...