Dear Th. Murugathas

Hello ; I can say that :

1) Ultrasonic Spray Pyrolysis (USP) is one of the important techniques to synthesize nano materials and to coat substrates with thin film coatings.

2) Ultrasonic spraying and atomization allows for full process control resulting in homogeneous high-quality output.

3) Ultrasonic spray pyrolysis excels conventional techniques, e.g. CVD by its homogeneous distribution and its cost-efficiency.

Ultrasonic Spray Pyrolysis (USP) is a a simple aerosol synthetic technique widely used for the synthesis of nano-materials such as thin films or nanoparticles. Due to its easy feasibility, flexibility and cost-efficiency, the USP method is an important alternative to the chemical vapor deposition (CVD). The precursors for ultrasonic spray pyrolysis are often prepared via sol-gel route. The composition of the synthesized nano-particles or the film can be easily modified via changes of the processing parameters. Ultrasonic spray pyrolysis gives you full control over the most important process parameters such as:

- ultrasonic amplitude

- precursor solution

- precursor composition/ viscosity

- flow rate

- deposition temperature

- substrate temperature

Ultrasonic Spray Pyrolysis for the Synthesis of Nano Particles When nano particles are synthesized via ultrasonic spray pyrolysis, organic and inorganic salts can be used as precursors for the preparation of metallic, oxidic and composite nano powders . The precursor solution is ultrasonically atomized before the fine-sized droplet mist goes into the furnace, where thermal decomposition of the material takes place. USP synthesized powders can be divided in three groups: Metals, e.g. Au, Ag, Co, Cu, Zn, Ni, Fe Oxides, e.g. TiO2, ZnO, Al2O3, RuO2 Composite materials with partially core-shell structure, e.g. CuNi, FeCo, NiCo, RuO2/TiO2,  La0.6Sr0.4CoO3,  C/LiFePO4,  Au/TiO2,  Ag/TiO2

Ultrasonic Spray Pyrolysis for Thin Film Coatings Via ultrasonic spray pyrolysis multi-layer coating can be produced, which is of special interest for the preparation of functionally graded films. By changing the precursor solution, the composition and the functionalities of the thin film coating can be easy and precisely modified.

Thank you Murugathas and Toufik Mahdaoui.yours information is useful for me.

And i want information How to contribute Ultrasonic wave and nitrogen carrier gas to grow Nanostructures(Nanorods,Nanowires,etc) for metal Oxide Semiconductors(Particularly SnO2).

Dear Murugathas,

In "Ultrasonic Spray Pyrolysis Technique" a solution containing precursor materials (in your case tin containing chloride, acetate etc.) is fed through the syringe pump. This solution is ultrasonically excited using piezoelectric crystals to generate very fine droplets. Droplet size, which is in micron size range, can be controlled by the oscillation frequency of the crystal. The droplets are transported by a carrier gas onto a heated substrate, where the precursor thermally decompose and form the thin film.

If you like to see details you can investigate following publications.

Conference Paper Ultrasonic Spray Deposition of CuInS2 Absorber Thin Films: E...

Article Influence of excitation frequency on structural and electric...

Article Preparation and characterization of cost effective spray pyr...

Techniques described in paper suggested by Murugathas and that used by Aydin are NOT the same. In fact, technique used in paper suggested by Murugathas was developped by the very first years of 70's at Grenoble, France, by a team of researchers working at the CENG, and was patented in France and the USA under the name o "Pyrosol process". There are a lot of papers and reviews on this technique. You only need to Google by "pyrosol process" or "ultrasonic spray pyrolysis" and you will get hundred of references, most of them available to download in PDF format. Even the original patent (either in french or english) can be downloaded. Technique used by Aydin is "the alternative way" to create the aerosol by ultrasonic means. Results got by this two techniques differs, depending on the process followed, as the thermodynamics of both are not the same. Pyrosol process can be developed to operate in a controlled closed environment (much in the same way that CVD process allows), while the ultrasonic impact nozzle doesn't allow this (because this is closer to the pneumatic spray pyrolysis). If you're worried about the close control of your growth environment, then you must use the Pyrosol process; otherwise, you can use any of them. The process used by Aydin is cheaper to built than the Pyrosol process.

you can make use of these links

Article A comprehensive review on ultrasonic spray pyrolysis techniq...

https://www.sciencedirect.com/topics/materials-science/spray-pyrolysis

Chapter Semiconductor Materials by Ultrasonic Spray Pyrolysis and Th...

Well, the BEST of all (as it's authored by those that take the ORIGINAL Pyrosol Process in charge, and concentrated the whole knowledge about ultrasonic spray pyrolysis) is:

M. Langlet and J.C. Joubert, “The pyrosol process or the pyrolysis of an ultrasonically generated aerosol”, in Chemistry of Advanced Materials, ed. by C.N.R. Rao (Blackwell; Oxford 1993; Distributed in the USA and North America by CRC Press) pp. 55-76.

Unfortunately it's not available online, but only through your librarian services.

Normally, ultrasonic waves are used to obtain little droplets of the desired solution, which later will become part of a thin film or powder. If you want to form nanostructures, I would start moving some known important parameters as temperature and molarity. As Arturo Tiburcio said, there are different USP setups, the cheaper ones, create the mist faraway from the substrate and then you use some carrier gas to move it. It exist nozzles with ultrasonic in there, these nozzles mix pneumatic and ultrasonic ways to obtain the mist.