Characterization of maghemite thin films prepared by sol-gel processing

Download

index.pdf

Date

2006

Author

Karakuşçu, Aylin

Metadata

Show full item record

Item Usage Stats

338
views

95
downloads

In this study, maghemite (γ-Fe2O3) thin films were prepared by chemical solution deposition on glass and quartz substrates. The solution was prepared by using 0.3 M iron (III) nitrate [Fe(NO3)3 - 9H2O] as precursor and dissolved in a mixture of 2-methoxyethanol and acetylacetone in a molar ratio of 20:2, by stirring the solution at RT for 2 hours. Substrates were prepared by either piranha etching method or ultrasonic cleaning method. The solution was spin coated on glass and quartz substrates at 1400 and 4000 rpm for 1 minute. The resultant film thickness was found as 65 and 80 nm by SEM. Viscosity of the main solution was found to be approximately as 0.0035 Pa.s by viscosity measurement. TGA/DTA analyses showed that, to produce maghemite thin film, heat treatment should be done between 330 °C and 440 °C. Homogeneous and crack free maghemite thin films were observed by Energy Dispersive Spectrometry (EDS) and Scanning Electron Microscope (SEM) methods. TEM studies verified maghemite thin film formation by using electron diffraction and SAED (selected area electron diffraction) method. Thin film characteristics were evaluated by changing the experimental parameters which are annealing temperature, annealing time and thickness of the films using XRD (x-ray diffraction) method. Optical band gap of maghemite thin films were found as approximately 2.64 eV by UV-VIS Spectrophotometer. Magnetic properties of maghemite thin films were also examined by VSM (vibrating sample magnetometer).

Subject Keywords

Metallurgy.

URI

http://etd.lib.metu.edu.tr/upload/12607795/index.pdf
https://hdl.handle.net/11511/16000

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Characterization of magnetite thin films produced by sol-gel processing Eken, Ali Erdem; Özenbaş, Ahmet Macit; Department of Metallurgical and Materials Engineering (2008) Magnetite (Fe3O4) thin films were prepared by a sol-gel process in which, a solution of iron (III) nitrate dissolved in ethylene glycol was applied on glass substrates by spin coating. Xerogel films were obtained by drying the coated films at 110 °C. The films were sintered between 300 °C and 450 °C in order to observe the phases existing in the films at different temperatures. Coating solution showed Newtonian behaviour and viscosity was found as 0.0215 Pa.s. DTA analysis showed that, sintering temperature...
Investigation of the effect of orientation and heat treatment on the stress corrosion cracking susceptibility of 7050 aluminium alloy Çevik, Gül; Doruk, Mustafa; Department of Metallurgical and Materials Engineering (2004) In the present work, the effect of variation in specimen orientation and heat treatment on the Stress Corrosion Cracking (SCC) susceptibility of 7050 aluminum alloy was investigated in 3,5% NaCl solution and under freely corroding conditions. For this purpose, Constant Extension Rate Tests (CERT) was performed on precracked Compact Tension (CT) specimens and the Direct Current Potential Drop technique was applied to measure the crack lengths. In addition to crack length versus time curves, the relationship ...
High temperature corrosion of steels used in petroleum refinery heaters Sultan, Abdelrahman; Karakaya, İshak; Department of Metallurgical and Materials Engineering (2005) The oxidation of three different steels used in the construction of petroleum refineryheaters was investigated by using thermogravimetric analysis technique (TGA). C-5,P-11, and P-22 steel samples were tested in two different oxidizing environments; air and CO2+N2+H2O (that simulates the combustion products of natural gas) at two different temperatures; 450oC and 500oC. In air oxidation P-22 had the best oxidation resistance among the three steels at two temperatures. In CO2+N2+H2O environment,C-5 possessed...
Microstructural characterization of hypoeutectoid steels quenched from the Ae1 - Ae3 intercritical temperature range by magnetic barkhausen noise technique Boyacıoğlu, Beril; Gür, Cemil Hakan; Department of Metallurgical and Materials Engineering (2006) This thesis aims to examine the possibility of using Magnetic Barkhausen Noise technique in characterizing the ferritic-martensitic microstructure of hypoeutectoid steels quenched from the intercritical temperature range. For this purpose, rectangular specimens were prepared from SAE 1020, 1040 and 1060 steels. The specimens were heated at different temperatures within the intercritical temperature range and then quenched into water. Microstructures of the specimens were characterized by metallographic exam...
Production and characterization of porous titanium alloys Esen, Ziya; Bor, Şakir; Department of Metallurgical and Materials Engineering (2007) In the present study, production of titanium and Ti6Al4V alloy foams has been investigated using powder metallurgical “space holder technique” in which magnesium powder were utilized to generate porosities in the range 30 to 90 vol. %. Also, sintering of titanium and Ti-6Al-4V alloy powders in loose and compacted condition at various temperatures (850-1250oC) and compaction pressures (120-1125 MPa), respectively, were investigated to elucidate the structure and mechanical properties of the porous cell walls...

Citation Formats

A. Karakuşçu, “Characterization of maghemite thin films prepared by sol-gel processing,” M.S. - Master of Science, Middle East Technical University, 2006.