scholarly journals Structural and Optical Studies of Potential Ferroelectric Crystal: KDP Doped TGS

2013 ◽  
Vol 6 (1) ◽  
pp. 1-9 ◽  
Author(s):  
P. R. Deepti ◽  
J. Shanti
Keyword(s):  
Infrared Detectors ◽  
Room Temperature ◽  
Grown Crystal ◽  
High Sensitivity ◽  
Ferroelectric Material ◽  
X Ray Diffraction ◽  
Optical Studies ◽  
Ferroelectric Crystal ◽  
X Ray ◽  
Vis Spectroscopy

Triglycine sulphate (TGS), an important ferroelectric material has been widely used in the fabrication of high sensitivity infrared detectors at room temperature. Single crystals of KDP doped TGS was grown by slow evaporation method at room temperature in this study. The grown crystal was characterized by UV-Vis spectroscopy, FTIR spectroscopy, powder X-ray diffraction studies, and ferroelectric studies. KDP doped TGS crystals were found to be highly transparent and full faced. The experimental results evidence the suitability of the grown crystal for optoelectronic applications.  Keywords: Crystal growth; KDP-doped TGS; Ferroelectric studies  © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.  doi: http://dx.doi.org/10.3329/jsr.v6i1.16584 J. Sci. Res. 6 (1), 1-9 (2014)

scholarly journals Growth, Optical and Microhardness Studies of 2-Aminothiazole- 3, 5-Dinitrobenzoic Acid Complex

2019 ◽  
Vol 1 (1) ◽  
pp. 42-45
Author(s):  
Tamiloli Devendhiran ◽  
Keerthika Kumarasamy ◽  
Mei–Ching Lin
Keyword(s):  
Room Temperature ◽  
Grown Crystal ◽  
Optical Transmittance ◽  
Dielectric Measurements ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
Acid Complex ◽  
X Ray ◽  
Slow Evaporation Technique ◽  
Evaporation Technique

Single crystals of 2-Aminothiazole 3,5-Dinitrobenzoic acid has been synthesized and good quality optical crystals were grown by slow evaporation technique at room temperature. The crystallinity nature of the grown crystal was confirmed from X-ray diffraction technique. An optical transmittance study was also carried out by UV – Vis spectra. FTIR spectra confirm the presence of functional groups in the grown crystal. The dielectric measurements were carried out in the range of 50Hz to 2MHz. The dielectric constant was seen to increase exponentially at lower frequencies. The microhardness studies were carried out using Vickers hardness indenter. Photoluminescence study shows that maximum emission occurs at 435nm.

On the tetragonality of the room-temperature ferroelectric phase of barium titanate, BaTiO3

2009 ◽  
Vol 42 (3) ◽  
pp. 480-484 ◽  
Author(s):  
Dean S. Keeble ◽  
Pamela A. Thomas
Keyword(s):  
Barium Titanate ◽  
Diffraction Pattern ◽  
Room Temperature ◽  
Ferroelectric Material ◽  
Tetragonal Symmetry ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Group Assignment ◽  
Growth Method

The room-temperature phase of the important ferroelectric material barium titanate, BaTiO3, was re-investigated by single-crystal X-ray diffraction on a sample grown by the top-seeded solution growth method, with the intention of demonstrating once again that the structure has tetragonal symmetry consistent with the space-group assignmentP4mmand thus resolving recent controversy in the scientific community and literature [Yoshimura, Kojima, Tokunaga, Tozaki & Koganezawa (2006).Phys. Lett. A,353, 250–254; Yoshimura, Morioka, Kojima, Tokunaga, Koganezawa & Tozaki (2007).Phys. Lett. A,367, 394–401]. To this end, the X-ray diffraction pattern of a small (341 µm3) sample of top-seeded solution-grown BaTiO3was measured using an Oxford Diffraction Gemini CCD diffractometer employing Mo Kα radiation and an extended 120 mm sample-to-detector distance. More than 104individual diffraction maxima observed out to a maximum resolution of 0.4 Å were indexed on two tetragonal lattices. These were identical to within the standard deviations on the lattice parameters and were related to each other by a single rotation of 119.7° about the [11\overline1] direction of the first tetragonal lattice (the major twin component), although the actual twinning operation that explains the observed diffraction pattern both qualitatively and quantitatively is shown to be conventional 90° twinning by them[101] operation. Importantly, it is not necessary to invoke either monoclinic symmetry or a coexistence of tetragonal and monoclinic phases to explain the observed diffraction data.

Growth and structural and physical properties of diisopropylammonium bromide molecular single crystals

2016 ◽  
Vol 49 (6) ◽  
pp. 2053-2062 ◽  
Author(s):  
Harsh Yadav ◽  
Nidhi Sinha ◽  
Sahil Goel ◽  
Abid Hussain ◽  
Binay Kumar
Keyword(s):  
Single Crystals ◽  
Grown Crystal ◽  
Three Dimensional ◽  
Solution Technique ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dielectric Constant And Loss ◽  
Vis Spectroscopy ◽  
Direct Band ◽  
Crystallographic Axes

Large single crystals of the promising molecular organic ferroelectric diisopropylammonium bromide (DIPAB) have been grown by the solution technique. A structural study was performed using single-crystal X-ray diffraction analysis. The twin element of a selected DIPAB crystal was identified by a morphological study. Intermolecular interactions present in the grown crystal were explored by Hirshfeld surface (three-dimensional) and fingerprint plot (two-dimensional) studies. In UV–vis spectroscopy, the DIPAB crystal has shown high transparency with a wide direct band gap of 5.65 eV. In the photoluminescence spectrum, sharp UV and blue emissions were observed at 370, 392, 417 and 432 nm. The electrical properties were investigated by measuring the dielectric constant (∊) and loss (tanδ) of the grown crystal. The DIPAB crystal exhibits a promising piezoelectric charge coefficient (d33) value of 18 pC N−1, which makes it suitable for transducer applications. A high ferroelectric Curie temperature (Tc≃ 425 K) with high remnant polarization (20.52 µC cm−2) and high coercive field (12.25 kV cm−1) were observed in the as-grown crystal. Vickers microhardness analysis shows that the value of Meyer's index (n= 7.27) belongs to the soft material range, which was also confirmed by void analysis along three crystallographic axes. It is shown that the DIPAB crystal has potential for optical, ferroelectric and piezoelectric applications.

scholarly journals Studies on the growth and characterization of L-cysteine hydrogen fluoride single crystal

2019 ◽  
Vol 37 (3) ◽  
pp. 304-309
Author(s):  
Azeezaa Varsha Mohammed ◽  
Suresh Sagadevan
Keyword(s):  
Single Crystal ◽  
Hydrogen Fluoride ◽  
Grown Crystal ◽  
Optical Band Gap ◽  
Second Harmonic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir

AbstractL-cysteine hydrogen fluoride (LCHF) single crystals were grown from aqueous solution. Single crystal X-ray diffraction, FT-IR, UV-Vis-NIR, and TG-DTA were used to test the grown crystals. The specimen dielectric and mechanical behaviors were also studied. Powder X-ray diffraction of the grown crystal was recorded and indexed. The optical properties of the LCHF crystal were determined using UV-Vis spectroscopy. It was found that the optical band gap of LCHF was 4.8 eV. The crystal functional groups were identified using FT-IR. Second harmonic generation (SHG) efficiency of the LCHF was three times higher than that of KDP. The dielectric constant, dielectric loss and AC conductivity were measured at different frequencies and temperatures.

Effect of Preparation on Microstructure of Ag-Loaded TiO2 Nanotube Arrays

2017 ◽  
Vol 748 ◽  
pp. 155-159
Author(s):  
Somkuan Photharin ◽  
Udom Tipparach
Keyword(s):  
Room Temperature ◽  
Ammonium Fluoride ◽  
Deionized Water ◽  
Nanotube Arrays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Titanium Foils ◽  
Anodization Method ◽  
Scanning Electron

We have synthesyzed TiO2 nanotubes by an anodization method. The cathode was titanium (Ti) sheets and anode was platinum (Pt). The electrolytes were mixtures of ethylene glycol (EG), ammonium fluoride (NH4F) and deionized water (DI water). The anodizing voltage was set to 50 V and the process was carried out for 2 h. The titanium foils were anodized at room temperature. Then Ag nanoparticles were loaded in TiO2 nanotube arrays by immersed in 50 ml solutions containing of AgNO3 (1.0, 1.5 and 2.0 mM) for 24 h. The morphology, structure, and optical properties of the prepared nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and and UV-vis spectroscopy (UV-vis) respectively. The structures of TiO2 nanotubes obtained from the nanotube arrays were crystallized by annealing at 450 °C for 2 h before immersed in solution and immersed in solution before crystallized by annealing are similar. When the concentration of silver nitrate (AgNO3) increases, the TiO2 nanotube arrays cracked and are not well arranged.

The Origin of the Ferroelectricity in the Bismuth Titanate Bi4Ti3O12 with Perovskite-Like Layered Structure

2015 ◽  
Vol 226 ◽  
pp. 17-22 ◽  
Author(s):  
Joanna A. Bartkowska ◽  
Jolanta Dercz ◽  
Daniel Michalik
Keyword(s):  
Room Temperature ◽  
Bismuth Titanate ◽  
Diffraction Method ◽  
Ceramic Materials ◽  
Ferroelectric Material ◽  
X Ray Diffraction ◽  
Electronic Industry ◽  
X Ray ◽  
Formation Behavior ◽  
Thermogravimetric Studies

The goal of this study was to investigate the origin of ferroelectricity in Bi4Ti3O12. The bismuth titanate Bi4Ti3O12 (BTO), which belongs to the Aurivillius family, is one of the most interesting compounds among the bismuth-based layered ceramics. BTO is a ferroelectric material with wide applications in the electronic industry, as capacitors, transducers, memory devices and sensors. Aurivillius structures are described with a general formula following form:Am-1Bi2BmO3m-1. BTO ceramic materials is an Aurivillius structure with m = 3. This ceramic materials were prepared by conventional mixed-oxide method of the solid state reaction. The temperature of the Bi4Ti3O12 sintering was selected on basis of thermogravimetric studies. The crystal structure of Bi4Ti3O12 was examined at room temperature with an X-ray diffraction method. Phase formation behavior was investigated using the differential thermal analysis (DTA) and the thermal gravimetric (TG). The microstructure was investigated by SEM method. Based on the Dorrian’s model, the value of displacements between bismuth ions and oxygen octahedra was calculated.

Preparation and Properties of Cupper and Iron Doped TiO2 Nanotubes by Anodization Method

2017 ◽  
Vol 744 ◽  
pp. 453-457
Author(s):  
Somkuan Photharin ◽  
Udom Tipparach
Keyword(s):  
Room Temperature ◽  
Anatase Phase ◽  
Ammonium Fluoride ◽  
Deionized Water ◽  
Titania Nanotubes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ordered Arrays ◽  
Vis Spectroscopy ◽  
Anodization Method

We have synthesized titania nanotubes by an anodization method. The anodization was carried out in a two-electrode configuration bath with Ti sheet as the anode and the Pt as the counter electrode. In this experiment, one face of the Ti foils was exposed to the electrolyte during anodization. The electrolytes were mixtures of ethylene glycol (EG), ammonium fluoride (NH4F) and deionized water (DI water) that contained of Cu and Fe dopants of 0.5 mM. The anodizing voltage was set to 50 V and the anodization was performed at room temperature for 2 h. The nanotubes were crystallized by annealing at 450°C for 2 h. The morphology, structure, and optical properties of the prepared nanotubes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-vis spectroscopy (UV-vis) respectively. The results show that titania nanotubes are anatase phase and the nanotubes are arranged in highly ordered arrays.

scholarly journals Synthesis of nanostructured (Ti-Zr-Si)N coatings deposited on Ti6Al4V alloy

2021 ◽  
Author(s):  
Leydi Julieta Cardenas-Flechas ◽  
Claudia Patricia Mejía-Villagran ◽  
Miryam Rincon-Joya ◽  
Jhon Jairo Olaya-Florez
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Scratch Test ◽  
Adhesive Failure ◽  
Cohesive Failure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Pin On Disc ◽  
Scanning Electron

d Zr targets. The synthesis of the coatings was carried out by varying the discharge power in the Ti5 well as a variation in the deposit temperature at room temperature 130° and 260°C. The coatings were characterized by means of X-ray diffraction (XRD), evidencing the formation of the phase that belongs to the solid solution (Zr, Ti)N, scanning electron microscopy (SEM), UV-Vis spectroscopy and hardness and pin-on-disc tests. The thickness was measured through interferometry with values between 662 and 481nm for the deposited coatings. According to the failure mechanism in the scratch test, the best results were obtained with a power of 170W and 260°C with a cohesive failure Lc1 = 2.1N and an adhesive failure Lc2 = 4.7N. 

Room Temperature Magnetoelectric Coupling, Electrical, and Optical Properties of BaFe2O4 – ZnO Nanocomposites

2019 ◽  
Vol 201 (1) ◽  
pp. 192-200
Author(s):  
Papia Dutta ◽  
S. K. Mandal ◽  
A. Nath
Keyword(s):  
Room Temperature ◽  
Morphological Analysis ◽  
Longitudinal Mode ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Solid State Route ◽  
Vis Spectroscopy ◽  
Magnetoelectric Response ◽  
Jonscher’S Power Law

Polycrystalline multiferroic nanocomposites with general formula xBaFe2O4 – (1 – x) ZnO (x = 0.2, 0.3, and 0.5) are prepared by chemical pyrophoric reaction method and solid-state route. The samples are characterized by X-ray diffraction which indicates the formation of both the phases in the composites. The morphological analysis and elemental compositions have been identified by using field emission scanning electron microscope and energy-dispersive X-ray analysis techniques. These micrographs reveal the particle sizes are in the nanometer dimension. The band gap of the nanocomposites is estimated employing UV-Vis spectroscopy. The DC electrical resistivity exhibits a metal-semiconductor transition for all the nanocompositions. Temperature-dependent AC conductivity of the nanocomposites is found to obey the Jonscher’s power law. The room temperature multiferroic behavior of the nanocomposites is confirmed from the detailed magnetoelectric response studies. The coupling coefficient is obtained maximum for x = 0.5 compositions for both in transverse and longitudinal mode due to the more ferrite content i.e., more magnetostrictive behaviour in the nanocompositions.

A Comparative Study of GaN Epitaxy on Si(001) and SI(111) Substrates

1992 ◽  
Vol 242 ◽  
Author(s):  
T. Lei ◽  
T. D. Moustakas
Keyword(s):  
Room Temperature ◽  
Stacking Faults ◽  
Room Temperature Resistivity ◽  
Defect Level ◽  
X Ray Diffraction ◽  
Optical Studies ◽  
X Ray ◽  
Cubic Gan ◽  
Gan On Si ◽  
Temperature Resistivity

ABSTRACTEpitaxial GaN films were grown on Si(001) and (111) substrates, using a two-step process. The films on Si(001) are single crystalline having the zincblende strucutrue, while those on Si(111) have the wurtzite structure. The crystalline qualities of the films were studied by X-ray diffraction. While the zincblende GaN has a perfect cubic structure, the wurtzitic GaN on Si(111) has a considerable amount of stacking faults along (0002) direction, which gives rise to significant zincblende component with (111) orientation. Room temperature resistivity for both type of GaN films was found to be larger than 100 Ω· cm. The temperature dependence of th resistivity gives a defect level at HOmeV for wurtzitic GaN and 80meV for cubic GaN. Optical studies show that GaN on Si(001) has a gap 3.2eV, and GaN on Si(111) has a gap of 3.4eV at room temperature.

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