scholarly journals Synthesis and Characterization of a Monoclinic Crystalline Phase of Hydroxyapatite by Synchrotron X-ray Powder Diffraction and Piezoresponse Force Microscopy

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 458 ◽  
Author(s):  
Ricardo Pérez-Solis ◽  
José Gervacio-Arciniega ◽  
Boby Joseph ◽  
María Mendoza ◽  
Abel Moreno

In this work, we report the synthesis of a monoclinic hydroxyapatite [Ca10(PO4)6(OH)2] (hereafter called HA) prepared by the sol-gel method assisted by ultrasound radiation at room temperature. The characterization of both the monoclinic and the hexagonal phases were performed by powder X-ray diffraction (PXRD) and using synchrotron radiation (SR). The measurement of the piezoelectricity was performed by piezoresponse force microscopy (PFM). The synthesis produced a mixture of monoclinic and hexagonal hydroxyapatite (HA). We also discuss the importance of stabilizing the monoclinic phase at room temperature with ultrasound irradiation. The existence of the monoclinic phase has important advantages in terms of showing piezoelectric properties for applications in the new medical rehabilitation therapies. Rietveld refinement of the PXRD data from SR indicated the monoclinic phase to be of about 81%. Finally, piezoelectric force microscopy was used to distinguish the phases of hydroxyapatite by measuring the average piezoelectric coefficient deff = 10.8 pm/V.

2017 ◽  
Vol 31 (02) ◽  
pp. 1750006 ◽  
Author(s):  
Mohammad Hossein Ghorbani ◽  
Abdol Mahmood Davarpanah

Manganese oxides are of more interest to researchers because of their ability as catalysts and lithium batteries. In this research, MnO2nanowires with diameter about 45 nm were synthesized by sol–gel method at room temperature (RT). Effect of increasing the annealing temperature from 400[Formula: see text]C to 600[Formula: see text]C on crystalline structure of nanostructure were studied and average crystallite size was estimated about 22 nm. X-ray Diffraction (XRD) method, Energy-Dispersive X-ray Diffraction (EDXD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM) were used to characterize the nanowires of MnO2.


2021 ◽  
Vol 43 (3) ◽  
pp. 314-314
Author(s):  
Ahmet Hamdi BAKIR and Handan ZL TORUN Ahmet Hamdi BAKIR and Handan ZL TORUN

The most important part of a solid oxide fuel cell is the ceramic electrolyte. In this study, cerium oxide (CeO2) was used as the ceramic electrolyte, and different dopant types were used to increase total conductivity. In this study, the most commonly used Sm, and the less frequently used Ho elements were doped simultaneously. As a result, the effect of dope and different synthesis methods on electrolyte properties was evaluated. Three rates were studied with the total amount of Sm-Ho being 20%. The effect of the dopant types on conductivity with critical radius effect was investigated. These dope types were placed in a CeO2 crystal lattice by using the sol-gel and hydrothermal methods. After synthesis, the stable phase was obtained at room temperature. X-ray powder diffraction (XRD) was used for phase determination. The thermogravimetry (TG) determined mass change. Scanning electron microscopy (SEM) was used in the analysis of surface morphology. Total conductivity measurements were measured by the four-probe dc method. After synthesis processes, cubic compounds were obtained. The total conductivity values of the cubic phases samples obtained by two different synthesis methods were compared. The highest conductivity was observed in the sol-gel compounds. The highest electrical conductivity Ce0.80Sm0.10Ho0.10O2 system sol- gel; 6.92x10-3(Ωcm)1- at 655 oC. It was found that the compound obtained as a result of the evaluations could be used ceramic electrolyte application.


2019 ◽  
Vol 09 (03) ◽  
pp. 1950025
Author(s):  
Dionizy Czekaj ◽  
Agata Lisińska-Czekaj

Research on synthesis, characterization and determination of processing — structure — property relationships of commercially important ferroelectric thin films has been performed. The sol–gel type solution deposition technique was applied to produce good quality thin films of [Formula: see text][Formula: see text]TiO3 (BST60/40) chemical composition on the stainless steel substrates. The thin films were characterized in terms of their microstructure, crystal structure, phase composition, piezoelectric and dielectric properties. It was found that the BST60/40 thin film adopted the cubic structure at room temperature with an elementary cell parameter [Formula: see text] Å. Morphology of the thin film surface was studied with Atomic Force Microscopy (AFM). Average roughness of the thin films surface was found ([Formula: see text]m). Piezoresponse Force Microscopy (PFM) was applied for the thin film characterization. Active piezoelectric regions were found in BST60/40 thin film. Therefore, dielectric response measured at room temperature was studied in assumption of piezoelectric electric equivalent circuit.


2010 ◽  
Vol 148-149 ◽  
pp. 1144-1147
Author(s):  
Xiang Rong Zhu ◽  
Lin Feng Lu ◽  
Hong Lie Shen

NixZn1-xFe2O4 (x=0.4, 0.6) powders are synthesized by sol-gel technique. The X-ray diffraction (XRD) measurements show their polycrystalline spinel structural characteristics. Both XRD and Atomic Force Microscopy demonstrate the samples are nanosized. At room temperature typical soft magnetism is exhibited by the samples. The reflection attenuation resulting from microwave absorption would reach to 1.9 dBm over the frequency range 6 GHz - 10 GHz when the samples are paved on a 10 cm  10 cm square aluminum plate with a thickness of about 0.35 mm.


2009 ◽  
Vol 67 ◽  
pp. 227-232 ◽  
Author(s):  
Gurpreet Singh ◽  
Amrish Panwar ◽  
Anjan Sil ◽  
Sudipto Ghosh

Nanocrystalline LiMn2O4 powder was synthesized by sol-gel method using citric acid as a chelating agent. The powders were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Differential scanning calorimetry (DSC), Differential thermal analysis (DTA), Impedance spectroscopy (IS) and Electrochemical measurements. The powder particles having slight agglomeration characteristics were found to have prismatic morphology and a wider size distribution from 50 nm to 200 nm, which provides good packing density of the material. The electrical conductivity of the powder at room temperature is in the order of ~10-5 S/cm. The structural stability of LiMn2O4 cubic spinel over the temperature range of battery operation was assessed. Electrochemical performance of the material shows a discharge capacity of ~130 mAh/gm.


NANO ◽  
2010 ◽  
Vol 05 (02) ◽  
pp. 127-132 ◽  
Author(s):  
DIDIK ARYANTO ◽  
ZULKAFLI OTHAMAN ◽  
AMIRA S. AMERUDDIN ◽  
ABD. KHAMIM ISMAIL

In0.5Ga0.5As quantum dots (QDs) stacked structure were studied using atomic force microscopy (AFM), high-resolution X-ray diffraction (HR-XRD) and photoluminescence (PL) characterization. Evolution in the dots size and dots density in the stacked structures is strongly influenced by the dot formation in the under-layer and the structure of the spacer layers. AFM results revealed that the dots formation on the top can be changed by increasing the number of stacked QDs. However, the dots formation is not vertically aligned since HR-XRD measurement gave different satellite peak on n-stacked QD structures. Room-temperature PL measurements show variation in the PL spectra, where blue-shifted PL peak positions are observed when the number of stack is increased. Variation in the HR-XRD and PL measurement is also attributed to the size, composition and density of the dots in the stacked structures.


2010 ◽  
Vol 1255 ◽  
Author(s):  
Zhengzheng Zhang ◽  
Camelia N Borca ◽  
D Wu ◽  
Alexei Gruverman ◽  
Orhan Kizikaya ◽  
...  

AbstractNo compositional variations of periodically poled lithium niobate (PPLN) (period of ~28 μm) are found using spatially resolved near edge X-ray adsorption fine structure (XANES) spectra taken at the Nb K-edge. The periodicity the ferroelectric domain patterns can be imaged using piezoresponse force microscopy (PFM) and atomic force microscopy (AFM) and the periodic variations in the optical properties of PPLN result in a nonlinear optical response in the IR region at a fixed scattering angle.


2016 ◽  
Vol 721 ◽  
pp. 394-398 ◽  
Author(s):  
Anzelms Zukuls ◽  
Gundars Mezinskis

Fe2O3–TiO2 coatings were successfully prepared on glass slide substrates using sol–gel method for wettability applications. The microstructure and surface properties of the coatings were extensively characterized by using X-ray diffractometry (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Different solutions were prepared by adding distilled water to sol solution. Glass substrates were coated by solutions of Ti-alkoxide, Fe-chloride hexahydrate, ethylene glycol, acetic acid, isopropanol and glycerol. The obtained gel films were dried at room temperature for 15 min in air. The oxide thin films were annealed at 500 ºC for 1h. The influence of distilled water concentration and withdraw speed on contact angle of the films was established. In addition, XRD results revealed that Fe2O3–TiO2 films composed of anatase, rutile, brookite and hematite phases. The purpose of this contribution was the investigation of different preparation parameters during the synthesis of iron oxide rich Fe2O3–TiO2 thin hydrophobic films on glass substrate. SEM and AFM observations revealed leaf-like structure formation on a coating surface.


2021 ◽  
Vol 37 (1) ◽  
pp. 177-180
Author(s):  
Alimuddin Alimuddin ◽  
Mohd Rafeeq

Synthesis of strontium oxide nanoparticles was carried out by sol –gel method using strontium nitrate and sodium hydroxide at room temperature which is very simple and cost effective. The characterization of strontium oxide nanoparticles was done using X-ray diffraction, scanning electron microscopy (SEM) and Fourier transform infra-red (FTIR). X-ray diffraction pattern indicates that the nanoparticles are crystalline in nature. The crystalline size of strontium oxide nanoparticle was calculated by Debye-Scherrer formula. The crystalline sizes are about 80nm. The morphology of nanoparticles was observed and investigated using SEM. The material at room temperature, calcined at 2000C, 400 0C and 6000C respectively shows pseudo spherical shape, cubic form and finally it becomes cylindrical this shows that there is a agglomeration with increase in temperature. FTIR spectrum of strontium oxide shows the peak at 854.64 cm-1 which is due to Sr -O bond.


2012 ◽  
Vol 10 (5) ◽  
pp. 1574-1583 ◽  
Author(s):  
Dalia Jonynaite ◽  
Darius Jasaitis ◽  
Rimantas Raudonis ◽  
Algirdas Selskis ◽  
Remigijus Juskenas ◽  
...  

AbstractIn the present work, the formation of cobalt aluminium spinel (CoAl2O4) as well as novel cobalt neodymium-aluminates with nominal compositions of CoAl1.75Nd0.25O4, CoAl1.5Nd0.5O4 and CoAlNdO4 by an aqueous sol-gel process and the sinterability of the products are investigated. The metal ions, generated by dissolving starting materials of metals in the diluted acetic acid were complexed by 1,2-ethanediol to obtain the precursors for the mixed metal ceramics. The phase purity of the synthesized compounds was characterized by powder X-ray diffraction analysis and infrared spectroscopy. The microstructural evolution and morphological features of the products were studied by scanning electron microscopy and atomic force microscopy, which together with the optical characterization of these new compounds showed that the sol-gel-derived materials could be successfully used as effective cobalt-based ceramic pigments.


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