Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Synthesis and characterization of lithium triborate by different synthesis methods and their thermoluminescent properties
Download
index.pdf
Date
2009
Author
Depci, Tolga
Metadata
Show full item record
Item Usage Stats
338
views
267
downloads
Cite This
Lithium triborate, (LiB3O5), is a technologically important material for diverse applications, such as nonlinear optical materials and surface acoustic wave devices or, etc. Furthermore, it is suggested as an efficient thermoluminescent material. LiB3O5, suitable to dosimetric usage, was produced by different synthesis methods which were high temperature solid state reaction, microwave solid state reaction, microwave assisted high temperature solid state reaction and precipitation assisted high temperature solid state reaction. After the synthesis, metal oxides were doped into LiB3O5 to enhance its thermoluminescent properties. Identification and characteristics of LiB3O5 were determined by X-ray diffraction (XRD), Fourier Transform Infra red (FTIR) analyses, Differential Thermal Analyses (DTA), Scanning Electron Microscopy (SEM) and Particle Size Analyzer. The glow curves were obtained by using thermoluminescent (TL) reader. Among four different synthesis methods applied, high temperature solid state method needs very high temperatures and long duration of heating. Therefore, the effect of the reaction temperature, the time intervals, and also starting materials on production of LiB3O5 were investigated. Characterization studies indicated that LiB3O5 could be produced at 710 °C for 4 hours. Among the starting materials used, Li2CO3 and H3BO3 combination was found the most suitable for the synthesis of LiB3O5 considering phase impurity as well as cost. LiB3O5 synthesized by microwave energy was unsuccessful. However, LiB3O5 could be synthesized by microwave assisted synthesis method by adding distilled water, urea and sucrose separately as thermal auxiliaries in microwave pre-heating step. The use of microwave and conventional ovens subsequently shortened the duration of heating. The crystallinity of LiB3O5 was the best in 40 % sucrose addition to initial mixture. The best method for synthesis of LiB3O5 has been found as precipitation assisted high temperature solid state method. This method yields LiB3O5 with higher phase purity as compared to these produced by other methods applied in this thesis and reported in the literature. It seems to be rather attractive since it is simple and needs less energy. Rare earth metal oxides, CuO and Al2O3 were added to LiB3O5 as activators to improve its TL properties. LiB3O5 synthesized by precipitation assisted high temperature solid state reaction and doped by 5 % wt Al2O3 showed the best TL property. Its main dosimetric characteristics revealed that LiB3O5 seemed to be suitable to medical and radiotherapy applications, since it was non-toxic, tissue equivalent, and chemically inert to body fluids.
Subject Keywords
Mining engineering.
,
Lithium.
,
Metallurgy.
URI
http://etd.lib.metu.edu.tr/upload/3/12610530/index.pdf
https://hdl.handle.net/11511/18805
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Synthesis of rare-earth doped lithium triborate
Ardıçoğlu, Burcu; Özbayoğlu, Gülhan; Department of Mining Engineering (2005)
Research in the field of non-linear optical (NLO) devices lead to an increasing interest in new borate compounds, capable of expanding the frequency range provided by common laser sources. Lithium triborate (LBO) is a newly developed ideal non-linear optical crystal used in laser weapon, welder, radar, tracker, surgery, communication, etc. Borates containing rare-earth elements are of great interest since they are found to be superior in non-linear optical applications. In this study, synthesis and identifi...
Modelling and noise analysis of closed-loop capacitive sigma-delta mems accelerometer
Boğa, Biter; Külah, Haluk; Department of Electrical and Electronics Engineering (2009)
This thesis presents a detailed SIMULINK model for a conventional capacitive Σ-Δ accelerometer system consisting of a MEMS accelerometer, closed-loop readout electronics, and signal processing units (e.g. decimation filters). By using this model, it is possible to estimate the performance of the full accelerometer system including individual noise components, operation range, open loop sensitivity, scale factor, etc. The developed model has been verified through test results using a capacitive MEMS accelero...
Efficient calibration of a multi-camera measurement system using a target with known dynamics
Aykın, Murat Deniz; Saranlı, Afşar; Department of Electrical and Electronics Engineering (2008)
Multi camera measurement systems are widely used to extract information about the 3D configuration or “state” of one or more real world objects. Camera calibration is the process of pre-determining all the remaining optical and geometric parameters of the measurement system which are either static or slowly varying. For a single camera, this consist of the internal parameters of the camera device optics and construction while for a multiple camera system, it also includes the geometric positioning of the in...
Development of a large area germanium on insulator platform by liquid phase epitaxy
Özyurt, Zişan İrem; Yerci, Selçuk; Department of Micro and Nanotechnology (2017)
Germanium is a group IV element compatible with CMOS (Complementary metal oxide semiconductor) fabrication technology and advantageous over silicon by having smaller band gap and higher carrier mobility, which provide infrared photodetectors and high-speed transistors respectively. In addition, by having direct band gap, strained-Ge enables fabrication of infrared lasers. Finally, thanks to lattice-matching, Ge layers on Si can also be used as virtual substrates for the growth of III-V compounds on Si. In o...
Synthesis of Emulsion-Templated Acrylic-Based Porous Polymers: From Brittle to Elastomeric
Tunc, Yeliz; Hasırcı, Nesrin; ULUBAYRAM, KEZBAN (2012-01-01)
High internal phase emulsion polymers (PolyHIPEs) are novel materials that have high porosity and interconnected open-cell structure and are used in various applications such as supports for catalytic systems, media for separation of similar molecules, and scaffolds for tissue engineering. In this study, 90% porous acrylic based polyHIPE structures with various cellular structure and mechanical characteristics were developed by using stearyl acrylate (SA), isodecyl acrylate (IDA), isobornyl methacrylate (IB...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
T. Depci, “Synthesis and characterization of lithium triborate by different synthesis methods and their thermoluminescent properties,” Ph.D. - Doctoral Program, Middle East Technical University, 2009.