Phase stability analysis of shocked ammonium dihydrogen phosphate by X-ray and Raman scattering studies

Author(s):  
Sivakumar Aswathappa ◽  
Arumugam Saranraj ◽  
Sahaya Jude Dhas Sathiyadhas ◽  
Kondaviti Showrilu ◽  
Martin Britto Dhas Sathiyadhas Amalapushpa

AbstractImpact of shock waves on non-linear optical materials bring about a lot of unknown behaviors of materials and such kinds of shock wave recovery experiments are highly required for the better understanding of material-property relationship. In the present context, we have performed experiments on the impact of structural properties of ammonium dihydrogen phosphate (ADP) samples under shock wave loaded conditions and the results of the test samples have been evaluated by X-ray diffraction (XRD), Raman spectroscopy, diffused reflectance spectroscopy (DRS) and field emission scanning electron microscopic (FESEM) technique. Interestingly, prismatic face of ADP shows loss of degree of crystallinity whereas pyramidal face shows enhancement of crystalline nature with respect to number of shock pulses due to shock wave induced dynamic re-crystallization. Hence, the present problem is worthy enough to unearth and understand the anisotropic nature of the ADP crystal and their structural modifications at shock wave loaded conditions.

2020 ◽  
Vol 235 (6-7) ◽  
pp. 193-202 ◽  
Author(s):  
Sivakumar Aswathappa ◽  
Eniya Palaniyasan ◽  
Sahaya Jude Dhas Sathiyadhas ◽  
Kalyana Sundar Jayaperumal ◽  
Sivaprakash Paramasivam ◽  
...  

AbstractBased on the importance of the shock recovery experiments, the authors report the structural and optical properties of pure and 0.001 M dye-doped potassium dihydrogen phosphate (KDP) crystals for virgin and shock wave loaded samples. Rhodamine B and Methylene blue dyes are selected as dopants to be doped with KDP crystal for the present investigation. The test crystals of pure and doped KDP crystals are grown by slow evaporation technique and cut and polished crystals of (200) face are used for the present investigation. Table-top pressure driven shock tube is utilized for the shock wave generation and the used functional Mach number is 1.7. Virgin and shock wave loaded test crystals’ surface morphology, structural properties and optical transmissions are observed using optical microscope, powder X-ray diffractometer and UV-Visible spectrometer, respectively. Crystalline nature and optical transmission of pure and doped KDP crystals are found to have reduced by the impact of shock waves. It occurs due to the enhancement of defect concentration on the surface of the test crystals. From the observed results, we assert that the pure KDP crystal is relatively more stable to shock wave induced damage compared to doped KDP crystals as reflected by structural and optical studies.


2019 ◽  
Vol 52 (5) ◽  
pp. 1016-1021 ◽  
Author(s):  
A. Sivakumar ◽  
S. A. Martin Britto Dhas

It is well known that super-cooled materials can be crystallized under the application of shock waves. This is the first report describing crystallization from unsaturated liquids. Shock-wave-induced crystallization of salts from environmental ground and sea water samples is explored. A table-top pressure-driven shock tube is utilized so as to produce the required shock waves of Mach numbers 1.1, 1.2, 1.4, 2.2 and 4.7. The demonstration comprises a train of acoustic shock pulses applied to the water samples. As a consequence of the impact of the shock waves, the colourless water becomes turbid, following which tiny crystallites are precipitated at the bottom of the vessel after a few minutes. The obtained precipitate is subjected to powder X-ray diffraction and energy-dispersive X-ray spectroscopy analysis to confirm the nature of the settled particles and the elements present in them, respectively. From the observed results, it is concluded that shock-wave-induced crystallization in water provides an alternative method for removing dissolved salts from both ground and sea water samples.


2019 ◽  
Vol 234 (9) ◽  
pp. 557-567 ◽  
Author(s):  
Sivakumar Aswathappa ◽  
Sahaya Jude Dhas Sathiyadhas ◽  
Balachandar Settu ◽  
Martin Britto Dhas Sathiyadhas Amalapushpam

Abstract In this research article, the authors pay attention to investigate the effect of structural and dielectric properties of ammonium dihydrogen phosphate (ADP) crystal under pre and post shock loaded conditions. A shock wave of Mach number 1.9 was utilized for the present investigation which was generated by a table-top pressure driven shock tube. The crystalline nature and grain size variations were estimated by powder X-ray diffraction technique. The grain size of post shock wave loaded ADP crystal is found to be larger than that of the pre shock wave loaded ADP crystal. The dielectric properties of the pre and post shock loaded crystals were analyzed by impedance analyzer as a function of frequency (1 kHz–1 MHz) at ambient temperature. The dielectric constant is observed to be varying from 346 to 362 at the frequency of 400 kHz for pre and post shock wave loaded ADP crystals, respectively. The obtained results suggest that shock waves can be an alternate tool to tailor the physical properties of materials without creating any change in the original crystal system and surface morphology.


2016 ◽  
Vol 675-676 ◽  
pp. 573-576 ◽  
Author(s):  
Pratya Thongpanit ◽  
Weerapong Chewpraditkul ◽  
Nakarin Pattanaboonmee

Ammonium dihydrogen phosphate (ADP) crystals is very interesting due to its nonlinear optical property. This study investigated on improving of material for academic use by adding boric acid to modify ADP crystals. Slow evaporation method in aqueous solutions of pure ADP and ADP doped with three concentrations of H3BO3 as 0.1, 1.0, 5.0 %wt were studied. The grown crystals were confirmed tetragonal structure by powder X-ray diffraction studies. The FTIR spectrum analysis presented various functional groups of boron in three conditions of doped ADP. TGA study was comfirned the temperature stability at 220 °C for both pure and doped ADP crytals. The machanical stress was analyzed by Vicker’s hardness measurement. The results of this analysis showed boric acid doped 1.0 %wt had superior machanical stress from 10 to 75 grams. ADP doped with boric acid at 1.0 %wt was accepted in all test properties.


1986 ◽  
Vol 4 (3-4) ◽  
pp. 413-419 ◽  
Author(s):  
R. Fabbro ◽  
B. Faral ◽  
J. Virmont ◽  
H. Pepin ◽  
F. Cottet ◽  
...  

A 9 μm thick aluminium foil is accelerated to a velocity of about 160 km/s by a laser of 0.26 μm wavelength and intensity of 1015 W/cm2 and collides with an aluminium impact foil. The measurement of the velocity of the induced shock wave in the impact foil, using a step method at the rear of the impact foil, gives pressures in the multi-hundred megabar range. The dynamics and constraints of this shock wave are presented and the effect of X-ray preheating, which can be important at this laser wavelength, is discussed.


2019 ◽  
Vol 52 (3) ◽  
pp. 599-604 ◽  
Author(s):  
Claudio Ferrari ◽  
Sara Beretta ◽  
Bianca Salmaso ◽  
Giovanni Pareschi ◽  
Gianpiero Tagliaferri ◽  
...  

A new type of X-ray facility, the Beam Expander Testing X-ray facility (BEaTriX), has been designed and is now under construction at INAF–Osservatorio Astronomico di Brera (Merate, Italy) to perform the acceptance tests of the silicon pore optics modules of the ATHENA X-ray telescope. Crystals of high perfection and large dimensions are needed in order to obtain a wide beam (20 × 6 cm) with an X-ray divergence of <0.5′′ and an X-ray energy purity ΔE/E < 10−5. To generate X-ray diffracted beams at an X-ray energy of 1.49 keV, ammonium dihydrogen phosphate (ADP) crystals have been considered among other possible choices, because of their reported crystal quality and because they can be grown at sufficiently large size at a reasonable price. In the present paper, the results of the characterization of crystalline quality and lattice planarity of a 20 × 20 × 2 mm ADP sample are reported.


2013 ◽  
Vol 785-786 ◽  
pp. 378-381
Author(s):  
Li Min Wang ◽  
Hong Ming Sun ◽  
Zhong Chao Ma ◽  
Ao Xuan Wang

The uniform hierarchical and microspheric copper oxide (CuO) nanostructures, which have been successfully prepared via a simple one-pot method. The detailed morphology and structure of the synthesized hierarchical and microspheric nanostructures were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) and UVvisible spectroscopy. The morphology of CuO particles depends on the ammonium dihydrogen phosphate (ADP) used in the synthesis, the formation mechanisms were proposed based on the experimental results. The catalytic activity of as-synthesized CuO was demonstrated by catalytic oxidation of methylene blue in the presence of hydrogen peroxide (H2O2) and CuO with hierarchical nanostructures was found to be the best catalyst.


2014 ◽  
Vol 979 ◽  
pp. 347-350
Author(s):  
Rungsarit Koonawoot ◽  
Cherdsak Saelee ◽  
Sakdiphon Thiensem ◽  
Sittiporn Punyanitya

This work reports the influence of chemical composition and sintering schedule on the properties of sintered bodies of hydroxyapatite (HA) bioceramic. The method of preparing sintered bodies by solid state reaction and uniaxial pressing. The raw material used calcium carbonate (CaCO3) and ammonium dihydrogen phosphate (NH4H2PO4) powder as precursors. These powders were mixed at CaCO3: NH4H2PO4 mass ratio of 1:0.697, 1:0.692, 1:0.689, 1:0.685 and 1:0.68, respectively. The compositions in the temperatures range of 800-1300 °C for 3 hour. The sintered bodies were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). Properties including phase, microstructures, porosity and bending strength of the samples. The results show that green bodies can be sintered at 1150 °C for 3 hours. This temperature found that crystals growth, highest of HA phase content in sintered bodies, good density and high efficiency strength properties.


2021 ◽  
Author(s):  
Vishnu Prabha Muthusamy ◽  
Vaideki Krishnakumar

Abstract Hydrolysis of a cellulose biomass results in breaking down the cellulose microfibrils into microcrystalline cellulose (MCC) or nanocrystalline cellulose (NCC) depending on the reaction conditions. Cellulose microfibrils are established robustly due to the synergistic interaction of van der Waals, inter- and intra-molecular hydrogen bonds and glycosidic bond between glucan moieties of cellulose polysaccharide. The hydrogen bonding network plays a crucial role in conforming cellulose chains into crystalline and amorphous region thereby determining its degree of crystallinity. The knowledge of hydrogen bonds in cellulose hence becomes indispensable to understand the crystallinity of cellulose before and after a hydrolysis reaction. However, the nature of hydrogen bonds after hydrolysis and how they contribute to the mechanical properties of resultant MCC/NCC are yet to be realized. This paper is therefore intended to discuss the degree of crystallinity of cellulose particles obtained after hydrolyzing waste cotton fibers (WCF) in two parts: part I, obtaining MCC with maximum total crystallinity index (TCI) by acid hydrolysis of WCF using Box Behnken Design; part II, comparing degree of crystallinity of MCC sample exhibiting highest TCI with that of WCF using analytical tools like X-ray Photoelectron Spectrometer, X-ray Diffractometer and Fourier Transform Infra- Red spectrometer. The physical dimension of MCC particle with maximum TCI has been verified using Field Emission Scanning Electron Microscopic images.


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