Effect of Precursor Sol Ageing on Sol-Gel Derived Ruthenium Oxide Thin Films

1999 ◽  
Vol 606 ◽  
Author(s):  
S. Bhaskar ◽  
S. B. Majumder ◽  
P. S. Dobal ◽  
R. S. Katiyar ◽  
A. L. M. Cruz ◽  
...  

AbstractIn the present work we have optimized the process parameters to yield homogeneous, smooth ruthenium oxide (RuO2) thin films on silicon substrates by a solution deposition technique using RuCl3.×.H2O as the precursor material. Films were annealed in a temperature range of 300°C to 700°C, and it was found that RuO2 crystallizes at a temperature as low as 400°C. The crystallinity of the films improves with increased annealing temperature and the resistivity decreases from 4.86µΩ-m (films annealed at 400°C) to 2.94pµΩ (films annealed at 700°C). Ageing of the precursor solution has a pronounced effect on the measured resistivities of RuO2 thin films. It was found that the measured room temperature resistivities increases from 2.94µΩ-m to 45.7µΩ-m when the precursor sol is aged for aged 60 days. AFM analysis on the aged films shows that the grain size and the surface roughness of the annealed films increase with the ageing of the precursor solution. From XPS analysis we have detected the presence of non-transformed RuCl3 in case of films prepared from aged solution. We propose, that solution ageing inhibits the transformation of RuCl3 to RuO2 during the annealing of the films. The deterioration of the conductivity with solution ageing is thought to be related with the chloride contamination in the annealed films.

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.


Author(s):  
Hamid Dadvar ◽  
Farhad E. Ghodsi ◽  
Saeed Dadvar

In this chapter, the sol-gel made titanium dioxide nanostructured thin films deposited on special substrates such as glasses, mica, steels, textiles, fibers, and other organic/inorganic substrates were reviewed. Through this review, several distinctive properties such as optical, electrical, photocatalytic, morphological, and mechanical properties of TiO2 nanostructured thin films were described. Also, a wide range of practical application of TiO2 nanostructured thin films such as dye-sensitised solar cells, optical coatings, humidity and gas sensors, selfcleaning, dielectric, and antibacterial surfaces were discussed in details. Dip and spin coating techniques were demonstrated as suitable methods for deposition of thin films. It has been shown that properties of such films can be affected by type of coating technique, stabilizer, precursor material, solvents, pH and viscosity of precursor solution, aging, and etc. Finally, Successive Interference Fringes Method (SIFM) was presented as a simple method for the determination of optical constants and thickness of TiO2 thin films from single transmission measurements.


2014 ◽  
pp. 218-250
Author(s):  
Hamid Dadvar ◽  
Farhad E. Ghodsi ◽  
Saeed Dadvar

In this chapter, the sol-gel made titanium dioxide nanostructured thin films deposited on special substrates such as glasses, mica, steels, textiles, fibers, and other organic/inorganic substrates were reviewed. Through this review, several distinctive properties such as optical, electrical, photocatalytic, morphological, and mechanical properties of TiO2 nanostructured thin films were described. Also, a wide range of practical application of TiO2 nanostructured thin films such as dye-sensitised solar cells, optical coatings, humidity and gas sensors, selfcleaning, dielectric, and antibacterial surfaces were discussed in details. Dip and spin coating techniques were demonstrated as suitable methods for deposition of thin films. It has been shown that properties of such films can be affected by type of coating technique, stabilizer, precursor material, solvents, pH and viscosity of precursor solution, aging, and etc. Finally, Successive Interference Fringes Method (SIFM) was presented as a simple method for the determination of optical constants and thickness of TiO2 thin films from single transmission measurements.


2014 ◽  
Vol 70 (a1) ◽  
pp. C725-C725
Author(s):  
Josef Bursik ◽  
Radomir Kuzel ◽  
Karel Knizek ◽  
Ivo Drbohlav

Hexagonal ferrites (M, Y, Z-type) represent a new diverse class of magnetoelectric (ME) multiferroics, where ME effect is driven by complex magnetic order. Integration of ME materials with standard semiconductor technology is important for ultimate realization of ME functionalities. They have the potential to display ME coupling under low magnetic field bias and at temperatures close to room temperature. Methods based on sol–gel transition offer possibility of low cost and efficient way for the evaluation of new material system. The single phase, epitaxial thin films of Y-type hexagonal ferrite has been prepared and studied. Thin films of Ba2Zn2Fe12O22(Y) hexaferrite were prepared through the chemical solution deposition method on SrTiO3(111)(ST) single crystal substrates using epitaxial SrFe12O19(M) hexaferrite thin layer as a seed template layer. The process of crystallization was mainly investigated by means of X-ray diffraction and atomic force microscopy. A detailed inspection revealed that growth of seed layer starts through the break-up of initially continuous film into high density of well-oriented isolated grains with expressive shape anisotropy and hexagonal habit.The vital parameters of the seed layer, i.e. thickness, substrate coverage,crystallization conditions and temperature ramp were optimized with the aim to obtain epitaxially crystallized Y phase. By overcoating this seed layer, Y phase prepared under optimum deposition and heat treatment conditions presents a (001) orientation perpendicular to the substrate. Perfect parallel in-plane alignment of the hexagonal cells of SrTiO3substrate and both hexaferrite phases was proved by fast ω and φ scan measurements on sets of several diffraction planes at asymmetric orientations, and also by pole figures. The soft magnetic character and existence of pronounced magnetic anisotropy in Y films were confirmed by room temperature measurements of magnetization.


1995 ◽  
Vol 10 (10) ◽  
pp. 2404-2407 ◽  
Author(s):  
A. Kashani ◽  
M.S. Tomar ◽  
E. Dayalan

Stoichiometric Sr1−xBaxNb2O6 (SBN) powder and thin films were prepared by a chemical method. The starting materials were niobium ethoxide and the hydroxides of strontium and barium. Powders were obtained by evaporation of the precursor solution, and thin films were deposited by spin coating. Annealing temperature required to obtain complete conversion to the crystalline material was about 700 °C. Stoichiometric polycrystalline films of Sr1−xBaxNb2O6 were deposited on quartz and silicon substrates. Leakage current-voltage and the capacitance-voltage measurements on a metal/SBN/n-silicon structure show a diode-type characteristic.


2000 ◽  
Vol 655 ◽  
Author(s):  
Jian-Gong Cheng ◽  
Jun Tang ◽  
Shao-Ling Guo ◽  
Jun-Hao Chu

AbstractBa0.8Sr0.2TiO3 thin films that are suitable for infrared detector applications have been prepared with a sol-gel process using a highly diluted precursor solution. Columnar structure with grain size close to 200 nm was obtained with layer-by-layer homoepitaxy due to a very small thickness of individual layer. The measured pyroelecrtic coefficient is larger than 3.1×10划4 C/m2K at the temperatures ranging from 10 to 26 °C and reaches the maximum value of 4.1×10划4 C/m2K at 16.8 °C. The infrared detectivity of 4.6×107 cmHz1/2W划1 has been obtained at 19 °C and 10 Hz in the Ba0.8Sr0.2TiO3 films deposited on thick (500 μm) platinum coated silicon substrates. The better infrared response can be expected by the improvement in the thermal isolation of pyroelectric element and the electrode materials.


2013 ◽  
Vol 3 ◽  
pp. 248-253 ◽  
Author(s):  
J.G. Quiñones-Galván ◽  
I.M. Sandoval-Jiménez ◽  
H. Tototzintle-Huitle ◽  
L.A. Hernández-Hernández ◽  
F. de Moure-Flores ◽  
...  

2011 ◽  
Vol 1352 ◽  
Author(s):  
Radomír Kužel ◽  
Lea Nichtová ◽  
Zdeněk Matěj ◽  
Zdeněk Hubička ◽  
Josef Buršík

ABSTRACTIn-situ laboratory measurements in X-ray diffraction (XRD) high-temperature chamber and detailed XRD measurements at room temperature were used for the study of the thickness, temperature and time dependences of crystallization of amorphous TiO2 thin films. The films deposited by magnetron sputtering, plasma jet sputtering and sol-gel method were analyzed. Tensile stresses were detected in the first two cases. They are generated during the crystallization and inhibit further crystallization that also depends on the film thickness. XRD indicated quite rapid growth of larger crystallites unlike the sol-gel films when the crystallites grow mainly by increasing of annealing temperature.


2001 ◽  
Vol 688 ◽  
Author(s):  
Kazunari Maki ◽  
Nobuyuki Soyama ◽  
Kaoru Nagamine ◽  
Satoru Mori ◽  
Katsumi Ogi

AbstractWe studied the crystallization of sol-gel derived Pb(Zr0.4Ti0.6)O3 [PZT(40/60)] thin films at 400 down to 390°C on Pt/SiO2/Si substrates by combination of diol-based solutions and modified film preparation processes. It was found that PZT films could be crystallized at 390°C and that PZT films crystallized at 400°C had microstructures with perovskite-single-phase columnar grains and good ferroelectric characteristics such as switched polarization (2 Pr) of 20 μC/cm2 and relative permittivity (εr) of 740. Next, we evaluated annealing temperature dependence of PZT(40/60) thin films crystallized at 390 to 435°C. The results indicated that (111)-orientation of perovskite phases became weaker, (100)-orientation of those became stronger, and the perovskite grain size increased with decreasing in annealing temperature.


2003 ◽  
Vol 18 (2) ◽  
pp. 357-362 ◽  
Author(s):  
Mary M. Sandstrom ◽  
Paul Fuierer

Control over crystallographic orientation in thin films is important, particularly with highly anisotropic structures. Because of its ferroelectric nature, the layered perovskite La2Ti2O7 has interesting piezoelectric and electrooptic properties that may be exploited when films are highly textured. Sol-gel films with an orientation factor of greater than 95% were fabricated without relying on epitaxial (lattice-matching) growth from the substrate. Film orientation and crystallization were confirmed by x-ray diffraction, scanning electron microscopy, atomic force microscopy, and optical measurements. The particle sizes in all precursor solutions were measured by dynamic light scattering experiments. Experimental results indicate that film orientation is a function of precursor solution concentration, size of the molecular clusters in the solution, and film thickness.


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