Microraman Study of PbTiO3 Thin Film Prepared by Sol-Gel Technique

1994 ◽  
Vol 343 ◽  
Author(s):  
E. Ching-Prado ◽  
A. Reynés-Figueroa ◽  
R. S. Katiyar ◽  
S. B. Majumder ◽  
D. C. Agrawal

ABSTRACTA PbTiO3 thin film prepared on silicon substrate by sol-gel technique has been studied by micro-Raman spectroscopy. The spectra, in comparison to the single crystal work, show high background in the low frequency region and Raman lines are broader, thus revealing the polycrystalline nature of the film. The frequencies of the Raman bands in the film are clearly shifted to lower frequencies compared to the corresponding ones in the single crystal or powder forms. This phenomenon is similar to the hydrostatic pressure effect on the Raman lines of PbTiO3 single crystal. The film, therefore, has grains under stress. This stress is caused by non-equilibrium defects and diffusion at the interface. Measurements at different film positions showed variation in the frequency and width of the Raman bands which are associated with the stress and grain size inhomogeneities. The measured shift in the Raman frequencies suggest grain sizes ≤l μm. XRD indicates grain size around 22 nm.

1994 ◽  
Vol 361 ◽  
Author(s):  
E. Ching-Prado ◽  
R.W. Tao ◽  
R.S. Katiyar ◽  
A.S. Bhalla

ABSTRACTThin films of PbTiO3 were prepared by sol-gel method on platinum-coated-Si and Al2O3 and annealed at 600°C. The annealing time of the films, deposited on Si, were 6 and 12 hours, respectively. Micro-Raman spectra show high background in the low frequency region and the bands are broader with respect to the single crystal work, which indicates the polycrystalline nature of the samples. The film annealed for 12 hours showed more pronounced peaks in the spectra when compared to the film annealed for 6 hours. Micro-Raman measurements on different spots in the film indicate that the PT film on platinum-coated silicon substrate is highly inhomogeneous. In the case of PT/Al2O3 such studies show a homogeneous film. The frequencies of most of the modes are decreased, which is associated to grains under stress. The nature of the stress is discussed. Although film stress may not be homogeneous, a stress value around 1.2 GPa is estimated from Raman data. XRD and SEM techniques were used for structural characterization.


2008 ◽  
Vol 1122 ◽  
Author(s):  
Gianguido Baldinozzi ◽  
David Simeone ◽  
Dominique Gosset ◽  
Mickael Dollé ◽  
Georgette Petot-Ervas

AbstractWe have synthesized Gd-doped ceria polycrystalline samples (5, 10, 15 %mol), having relative densities exceeding 95% and grain sizes between 30 and 160 nm after axial hot pressing (750 °C, 250 MPa). The samples were prepared by sintering nanopowders obtained by sol-gel chemistry methods having a very narrow size distribution centered at about 16 nm. SEM and X-ray diffraction were performed to characterize the sample microstructures and to assess their structures. We report ionic conductivity measurements using impedance spectroscopy. It is important to investigate the properties of these systems with sub-micrometric grains and as a function of their composition. Therefore, samples having micrometric and nanometric grain sizes (and different Gd content) were studied. Evidence of Gd segregation near the grain boundaries is given and the impact on the ionic conductivity, as a function of the grain size and Gd composition, is discussed and compared to microcrystalline samples.


2021 ◽  
pp. 413613
Author(s):  
Xin Liu ◽  
Xinyu Li ◽  
Xiang Li ◽  
Qiulian Li ◽  
Daoyong Zhang ◽  
...  

2015 ◽  
Vol 44 (6) ◽  
pp. 425-429 ◽  
Author(s):  
Kh. Sokhrabi Anaraki ◽  
N. V. Gaponenko ◽  
M. V. Rudenko ◽  
V. V. Kolos ◽  
A. N. Petlitskii ◽  
...  

2010 ◽  
Vol 150-151 ◽  
pp. 1484-1487 ◽  
Author(s):  
Tao Lin ◽  
Xiang Chao Zhang

Titanium dioxide thin film has been successfully synthesized deposited on ITO glass substrates by the sol–gel dip-coating method using freeze drying technique. The precursor and TiO2 film were characterized using XRD, AFM and UV-vis absorption spectra analysis technologies. The XRD result demonstrates that the TiO2 film is well crystallized and consists of anatase phase only with (101) plane. The morphology of the nanoparticles of TiO2 thin film is spherical shape with grain size of 30.1 nm in average diameter and the surface of the TiO2 film is smooth. There is a strong wide UV absorption band around 387 nm and the calculated band gap (Eg) value of the TiO2 thin film is about 3.18 eV. The water contact angles for the thin film was only about 12°. The freeze drying-assisted sol-gel technique offers a novel process route in treating hydrophilic glasses for self-cleaning building materials and would be widely application for building energy saving.


2016 ◽  
Vol 852 ◽  
pp. 1080-1086
Author(s):  
Xiao Xin Zhang ◽  
Jian Jun Xie ◽  
Ying Shi ◽  
Ling Cong Fan ◽  
De Bao Lin ◽  
...  

Lutetium oxyorthosilicate (Lu2SiO5, LSO) doped with Pr3+ was synthesized on cleaned silicon (111) substrates by sol-gel route with the spin-coating technique. XRD patterns indicated that the films were crystallized into A-type LSO phase at 1000 °C, followed by a phase transition to B-type LSO occurred at 1100 °C. SEM observations revealed that the surface of the films was smooth, homogeneous and crack-free. When the sintering temperature was 1000 °C, the average grain size of the crystal particles was 100-200 nm and the thickness of the thin film was about 380 nm when the coating layer number up to 10. While the sintering temperature was 1100 °C, the average grain size of the crystal particles was 200-300 nm and the thickness of the thin film was about 320 nm also 10 layers. PL spectra showed when under 1000 °C, the quenching concentration of Pr3+ was 0.3 mol%, the characteristic emission peaks was 289 nm and 340 nm and the dominant decay time was 4.64 ns; while under 1100 °C, the quenching concentration of Pr3+ was 0.4 mol%, the characteristic emission peaks was 280 nm and 320 nm and the dominant decay time was 2.61 ns.


2011 ◽  
Vol 312-315 ◽  
pp. 1038-1043 ◽  
Author(s):  
Salina Muhamad ◽  
Abu Bakar Suriani ◽  
Rafidah Ahmad ◽  
Anuar Ahmad ◽  
Yosri M. Siran ◽  
...  

In this study, MgxZn1-xO thin film with x varied from 0 to 0.3 was deposited on silicon with the orientation of [1 0 0] using the sol-gel method and spin coating technique. The thin film was annealed at 550°C before being used as a template to grow vertically aligned carbon nanotubes (VACNTs). Field emission scanning electron microscopy (FESEM) indicates that the top view of VACNTs’ topography are very similar to the topography of the template used, MgxZn1-xO thin film. When the value of x increased, the grain size of the template becomes larger and rougher, which were also true with the VACNTs. The electrical properties were measured using IV measurement system, which indicates that the conductivity of the VACNTs is directly proportional to the grain size of the template. Raman spectroscopy was used to inspect the crystal orientation.


1997 ◽  
Vol 485 ◽  
Author(s):  
Claudine M. Chen ◽  
Harry A. Atwater

AbstractWith a selective nucleation and solid phase epitaxy (SNSPE) process, grain sizes of 10 μm have been achieved to date at 620°C in 100 nrm thick silicon films on amorphous SiO2, with potential for greater grain sizes. Selective nucleation occurs via a thin film reaction between a patterned array of 20 rnm thick indium islands which act as heterogeneous nucleation sites on the amorphous silicon starting material. Crystal growth proceeds by lateral solid phase epitaxy from the nucleation sites, during the incubation time for random nucleation. The largest achievable grain size by SNSPE is thus approximately the product of the incubation time and the solid phase epitaxy rate. Electronic dopants, such as B, P, and Al, are found to enhance the solid phase epitaxy rate and affect the nucleation rate.


1997 ◽  
Vol 493 ◽  
Author(s):  
Han Wook Song ◽  
Joon Sung Lee ◽  
Dae-Weon Kim ◽  
Kwang Ho Kim ◽  
Tae-Hyun Sung ◽  
...  

ABSTRACTMgO thin films were deposited on Si(100) substrate with different temperatures from 500 °C to 800 °C and different e-beam powers from 25W to 100W using e-beam evaporation method. Pb(Zr0.53Ti0.47)O3(PZT) thin films were deposited on MgO/Si(100) substrates with different drying temperatures from 190 °C to 310 °C using sol-gel technique. If there were no buffer layer between the PZT thin film and Si substrate, the peaks corresponding to perovskite PZT phase were not observed. However the buffer layer were inserted between the PZT thin film and Si substrate, it was possible to fabricate perovskite PZT phase. The barrier effects of MgO thin film to the interdiffusion of Pb were investigated by AES study. Optimum thickness of MgO at which PZT/MgO/Si structure shows P-E hysteresis was calculated, and the hysteresis was tested for PZT/MgO/Si structures with different MgO thicknesses.


2007 ◽  
Vol 43 (2) ◽  
pp. 223-226 ◽  
Author(s):  
Ibrahim H. Mutlu ◽  
Maharram Z. Zarbaliyev ◽  
Ferhat Aslan

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