Fabrication and Photoelectric Properties of La-Doped ZnO Nanofibers via Electrospinning

2015 ◽  
Vol 733 ◽  
pp. 257-260 ◽  
Author(s):  
Yi Chen Liu ◽  
Xu Yan ◽  
Wen Peng Han ◽  
Hong Di Zhang ◽  
Yun Ze Long

La-doped ZnO nanofibers were fabricated via electrospinning and calcination at 800°C. The surface morphology and crystal structure of the La-doped ZnO nanofibers were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The photoelectric properties of La-doped ZnO nanofibers were also investigated. It was found that the photoelectric current increased obviously under light illumination (308 nm and 365 nm). However, the photocurrent reduced with increasing La-doping level, which may be ascribed to the increased defects inducing by La-doping.

2009 ◽  
Vol 620-622 ◽  
pp. 529-532
Author(s):  
Tie Kun Jia ◽  
Wei Min Wang ◽  
Zheng Yi Fu ◽  
Fei Huang ◽  
Hao Wang

La doped ZnO nanorods were synthesized via solvothermal technique using Zn(AC)2 and La(NO3)3 as starting materials. The products were characterized by X-ray diffraction (XRD), field scanning electron microscopy (FESEM) equipped with an energy dispersion X–ray (EDX) spectrometer, photoluminescence spectroscopy and UV-vis spectroscopy. The results of XRD in combination with EDS indicated that La was successful doped in ZnO. The obtained La doped ZnO sample exhibited nanorod like morphology and the diameter was about 30 nm. The photocatalytic property of La doped ZnO was evaluated by the variation of the concentration of RhB.


2021 ◽  
pp. 1-6
Author(s):  
Mariana M. V. M. Souza ◽  
Alex Maza ◽  
Pablo V. Tuza

In the present work, LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites were synthesized by the modified Pechini method. These materials were characterized using X-ray fluorescence, scanning electron microscopy, and powder X-ray diffraction coupled to the Rietveld method. The crystal structure of these materials is orthorhombic, with space group Pbnm (No 62). The unit-cell parameters are a = 5.535(5) Å, b = 5.527(3) Å, c = 7.819(7) Å, V = 239.2(3) Å3, for the LaNi0.5Ti0.45Co0.05O3, a = 5.538(6) Å, b = 5.528(4) Å, c = 7.825(10) Å, V = 239.5(4) Å3, for the LaNi0.45Co0.05Ti0.5O3, and a = 5.540(2) Å, b = 5.5334(15) Å, c = 7.834(3) Å, V = 240.2(1) Å3, for the LaNi0.5Ti0.5O3.


2007 ◽  
Vol 26-28 ◽  
pp. 243-246
Author(s):  
Xing Hua Yang ◽  
Jin Liang Huang ◽  
Xiao Wang ◽  
Chun Wei Cui

BaBi4-xLaxTi4O15 (BBLT) ceramics were prepared by conventional solid phase sintering ceramics processing technology. The crystal structure and the microstructure were detected by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD analyses show that La3+ ions doping did not change the crystal structure of BBT ceramics. The sintering temperature increased from 1120°C to 1150°C with increasing Lanthanum content from 0 to 0.5, but it widened the sintering temperature range from 20°C to 50°C and refined the grain size of the BBT ceramic. Additionally, polarization treatment was performed and finally piezoelectric property was measured. As a result, the piezoelectric constant d33 of the 0.1at.% doped BBLT ceramics reached its highest value about 22pc/N at polarizing electric field of 8kV/mm and polarizing temperature of 120°C for 30min.


2020 ◽  
Author(s):  
Yongcheng Lu ◽  
Yuanxun Li ◽  
Daming Chen ◽  
Rui Peng ◽  
Qinghui Yang ◽  
...  

Abstract In order to explore an economical functional phase alternative material for thick film resistors, the crystal structure, microstructure, and electrical properties of (1-x)LSCN + xLCNZ (x = 0.0–1.0) composite ceramics were studied through solid-state reaction experiments. The composite ceramics were characterized by x–ray diffraction, scanning electron microscopy, energy dispersive x–ray spectroscopy, and DC four–probe method. Results suggested that the main phases of LSCN and LCNZ were formed, along with a small part of impurity phases. The addition of LCNZ to LSCN decreased the electrical conductivity and changed the TCR from positive to negative. Zero TCR could be achieved around 0.6 < x < 0.8 and relatively low absolute TCR values could be obtained for the samples of 0.4 ≤ x ≤ 0.8. The ceramic of 0.6LSCN + 0.4LCNZ showed the optimal performances of conductivity = 1923 S/cm, TCR = 379.54 ppm/℃, and relative density = 95.05%.


2013 ◽  
Vol 802 ◽  
pp. 119-123
Author(s):  
Supamas Wirunchit ◽  
Rangson Muanghlua ◽  
Supamas Wirunchit ◽  
Wanwilai Vittayakorn ◽  
Naratip Vittayakorn

Nanocrystalline barium zirconium titanate, BaZr0.4Ti0.6O3, was synthesized successfully via the sonochemical process. The effects of reaction time on the precipitation of Ba(Zr,Ti)O3 particles were investigated briefly. The crystal structure as well as molecular vibrations and morphology were investigated. X-ray diffraction indicated that the powders exhibited a single phase perovskite structure, without the presence of pyrochlore or unwanted phases at the reaction time of 60 min. Nanocrystals were formed before being oriented and aggregated into large particles in aqueous solution under ultrasonic irradiation. A scanning electron microscopy (SEM) photograph showed the BZT powder as spherical in shape with uniform nanosized features.


Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2759 ◽  
Author(s):  
Ioannis Papadimitriou ◽  
Claire Utton ◽  
Panos Tsakiropoulos

The Al-Nb-Sn phase diagram was studied experimentally in the Nb-rich region to provide important phase equilibria information for alloy design of Nb-silicide based materials for aero engine applications. Three alloys were produced: Nb-17Al-17Sn, Nb-33Al-13Sn and Nb-16Al-20Sn (at.%). As-cast and heat-treated alloys (900 and 1200 °C) were analysed using XRD (X-ray diffraction) and SEM/EDS (scanning electron microscopy/ electron dispersive x-ray spectroscopy). Tin showed a high solubility in Nb2Al, reaching up to 21 at.% in the Sn-rich areas, substituting for Al atoms. Tin and Al also substituted for each other in the A15 phases (Nb3Al and Nb3Sn). Tin showed limited solubility in NbAl3, not exceeding 3.6 at.% as it substituted Al atoms. The solubility of Al in NbSn2 varied from 4.8 to 6.8 at.%. A ternary phase, Nb5Sn2Al with the tI32 W5Si3 crystal structure, was found to be stable. This phase was observed in the 900 °C heat-treated samples, but not in the 1200 °C heated samples.


2013 ◽  
Vol 543 ◽  
pp. 63-67
Author(s):  
Jayabharathi Jayaraman ◽  
Jayamoorthy Karunamoorthy

A sensitive benzimidazole derivative fluorescent sensor for nanoparticulate ZnO has been designed and synthesized. The nanocrystalline ZnO, Ag doped ZnO and Cu doped ZnO have been synthesised by sol-gel method and characterized by powder X-ray diffraction, scanning electron microscopy (SEM) and UV-visible diffuse reflectance, photoluminescence and electrochemical impedance spectroscopies. The synthesized sensor emits fluorescence at 360 nm and this fluorescence is selectively enhanced by nanocrystalline ZnO. This technique is sensitive to detect and estimate ZnO at micro molar level. Impurities such as Ag and Cu do not hamper the sensitivity of this technique significantly. Keywords: Sensor, SEM, EDX, Impedance, Fluorescence


2010 ◽  
Vol 173 ◽  
pp. 102-105 ◽  
Author(s):  
Khairul Arifah Saharudin ◽  
Srimala Sreekantan

In this paper, anodization of Ti foil was carried out in ethylene glycol (EG) containing 5 wt% NH4F solution and 0 to 1.5 wt% of water at 50 V for 60 min. The pH of the bath was kept constant at ~pH7. The crystal structure was studied by X-Ray Diffraction (XRD) analysis, and the morphology was observed via field emission scanning electron microscopy (FESEM). TiO2 nanotube with aspect ratio of 100 was obtained in EG containing less than 1wt % water. The nanotubes wall was very smooth. Increasing the water content > 1wt % results in short nanotubes of approximately 6.2μm with aspect ratio of 62. As anodized, nanotubes were amorphous and annealed at 400 °C promote 100 % anatase phase. Photocatalytic activity of the nanotubes produced at different water content was also evaluated by the degradation of methyl orange and the detail of the observation was discussed thoroughly in this paper.


2015 ◽  
Vol 819 ◽  
pp. 198-203
Author(s):  
Nur Farahin Abdul Hamid ◽  
Rozana Aina Maulat Osman ◽  
Mohd Sobri Idris ◽  
Tze Qing Tan

La-doped barium titanate (BaTiO3) was prepared using conventional solid state synthesis route. All peaks for sample x=0 are approaching the phase pure of BaTiO3 structure with tetragonal crystal structure (P4mm). Sintering of pressed powder are performed at 1300oC, 1400oC and 1450oC for overnight for pure BaTiO3 and 1350oC for 3 days for BaTiO3 doped lanthanum with intermittent grinding. Phase transition was studied by different x composition. The changes in the crystal structure of the composition x=0.1 and 0.2 were detected by using X-ray diffraction (XRD). The phase changes between tetragonal-cubic and cubic-tetragonal depending on the temperature. Rietveld Refinement analysis is carried out to determine the lattice parameter and unit cell for BaTiO3.


2011 ◽  
Vol 356-360 ◽  
pp. 565-568
Author(s):  
Shao Hong Wei ◽  
Mei Hua Zhou ◽  
Wei Ping Du

Pure ZnO and SnO2-ZnO nanofibers were synthesized by electrospinning method and characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure and methanol sensing properties of these fibers were investigated. The results indicate that the 20 wt% SnO2-ZnO sensor exhibits considerable sensitivity, rapid response, and good selectivity against methanol at 200 °C due to the special 1D fibers properties and the promoting effect of SnO2/ZnO heterojunction structure. The methanol sensing mechanism of SnO2-ZnO nanofibers were also discussed.


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