scholarly journals Structural and Surface Morphology Studies of La0.67Ba0.33(Mn1−xAlx)O3Thin Films Prepared by Sol-Gel Method

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
H. Abdullah ◽  
M. S. Zulfakar

Nanocrystalline thin films of La0.67Ba0.33(Mn1−xAlx)O3(x=0.00,0.05,0.10, and 0.15) were prepared by sol-gel method, as a starter material consisting of La2O3, BaNO3, Mn(NO3), and Al(NO3). The molarities of La2O3and BaNO3are constant, while molarities of Mn(NO3) and Al(NO3) were calculated based on stoichiometric theory. Thin films were deposited on quartz glass substrate by using spin coating technique and sintered at 700°C. X-ray diffractometer (XRD) patterns showed that these thin films consist of pure La0.67Ba0.33(Mn1−xAlx)O3phase where the most prominent peak is observed at (104). All the samples display a rhombohedral structure. Scanning electron microscopy (SEM) showed that aggregation of small particles occurred more in doped films than in undoped films. The surface morphology has been studied by using AFM, and the roughness of thin films was analyzed.

2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.


2012 ◽  
Vol 501 ◽  
pp. 76-80
Author(s):  
Mohammad Hafizuddin Haji Jumali ◽  
Siti Mariam Mohamad ◽  
Rozidawati Awang ◽  
Muhammad Yahaya ◽  
Mohd Riduan M. Said ◽  
...  

The effect of annealing temperatures on the formation of pure perovskite Na0.5Bi0.5TiO3 (NBT) based ceramics prepared by sol gel method has been investigated. The NBT sol was prepared using NaCH3COO, C6H9BiO6 and Ti(C4H9)4 with 2-methoxyethanol and glacial acetic acid were used as solvents. The BaTiO3 sol was synthesized using C4H6BaO4 and Ti(C4H9)4 with acetic acid and ethanolamine were used as solvents. The (Na0.5Bi0.5)0.96Ba0.04TiO3 (NBBT) sol was prepared by mixing appropriate amount of NBT and BaTiO3 sols. Then NBT and NBBT sols were dried at 200oC for 24 h, ground and subsequently annealed at temperatures ranging from 440oC – 640oC for 5 min. Formation of NBT and NBBT ceramics was examined using XRD technique. X-ray diffractograms reveal that the NBT ceramic with rhombohedral structure starts to form at 540oC and complete crystallization is achieved at 620oC. Addition of 4vol% of BaTiO3 sols drastically reduces the crystallization temperature of NBBT ceramic to 460oC and a pure single phase ceramic is achieved at 520oC. Despite retaining the same rhombohedral structure, the NBBT exhibits lattice parameters expansion indicating a successful Ba substitution which is also confirms by the absence of BaTiO3 peaks in the diffractograms. Both ceramics exhibit great thermal stability with additional increment in annealing temperatures.


2017 ◽  
Vol 05 (01) ◽  
pp. 1750004
Author(s):  
R. Vettumperumal ◽  
S. Kalyanaraman ◽  
R. Thangavel

Nanocrystalline ruthenium (Ru)-doped ZnO thin films on sapphire substrate was prepared using sol–gel method by spin coating technique. The structural and I-V characteristics of Ru doped ZnO thin films were studied from the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) analysis and Raman spectroscopy. X-ray diffraction (XRD) results revealed that the deposited films belonged to hexagonal wurtzite structure with c-axis orientation. It is also confirmed from the Raman spectra. Enhancement of longitudinal optical (LO) phonon is observed by the strong electron–phonon interaction. An observed increment in sheet resistance with increase in dopant percentage of Ru (1–2[Formula: see text]mol%) in ZnO films was found and better I-V characteristic behavior was observed at 1[Formula: see text]mol% of Ru-doped ZnO thin films. Trap limited current flow inside the material was calculated from the log I versus log V plot in the higher voltage region.


Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1444 ◽  
Author(s):  
Jiaxi Wang ◽  
Li Luo ◽  
Chunlong Han ◽  
Rui Yun ◽  
Xingui Tang ◽  
...  

Ferroelectrics have recently attracted attention as a candidate class of materials for use in photovoltaic devices due to their abnormal photovoltaic effect. However, the current reported efficiency is still low. Hence, it is urgent to develop narrow-band gap ferroelectric materials with strong ferroelectricity by low-temperature synthesis. In this paper, the perovskite bismuth ferrite BiFeO3 (BFO) thin films were fabricated on SnO2: F (FTO) substrates by the sol–gel method and they were rapidly annealed at 450, 500 and 550 °C, respectively. The microstructure and the chemical state’s evolution with annealing temperature were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS), and the relationship between the microstructure and electric, optical and photovoltaic properties were studied. The XRD, SEM and Raman results show that a pure phase BFO film with good crystallinity is obtained at a low annealing temperature of 450 °C. As the annealing temperature increases, the film becomes more uniform and has an improved crystallinity. The XPS results show that the Fe3+/Fe2+ ratio increases and the ratio of oxygen vacancies/lattice oxygen decreases with increasing annealing temperature, which results in the leakage current gradually being reduced. The band gap is reduced from 2.68 to 2.51 eV due to better crystallinity. An enhanced photovoltaic effect is observed in a 550 °C annealed BFO film with a short circuit current of 4.58 mA/cm2 and an open circuit voltage of 0.15 V, respectively.


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