Effect of rotation speed and pulling rate on physical properties of titanium-doped sapphire single crystals

Titanium-doped sapphire single crystals with 0.20 weight percentage of dopant were successfully produced by using the Automatic Diameter Control-Crystal Growth System based on the Czochralski technique. Group A crystals were produced at a constant pulling rate of 1.50 mm h-1 and a rotational speed (...

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Main Author: Jainal, Mohammad Nabil
Format: Thesis
Language:English
Published: 2013
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Online Access:http://eprints.utm.my/id/eprint/50696/25/MohammadNabilJainalMFS2013.pdf
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spelling my-utm-ep.506962020-07-08T08:48:07Z Effect of rotation speed and pulling rate on physical properties of titanium-doped sapphire single crystals 2013-04 Jainal, Mohammad Nabil QC Physics Titanium-doped sapphire single crystals with 0.20 weight percentage of dopant were successfully produced by using the Automatic Diameter Control-Crystal Growth System based on the Czochralski technique. Group A crystals were produced at a constant pulling rate of 1.50 mm h-1 and a rotational speed (8-24) rpm and Group B crystal were produced at a constant rotational speed of 15 rpm and pulling rate (0.75-1.75) mm h-1. The presence of macroscopic defects such as gas bubbles and inclusions were found in the crystals produced at low rotation speed and at high pulling rate. XRD spectra of the crystals identified synthetic corundum as the main phase of the crystals and Al2TiO5 as the second phase. EDAX analysis showed the presence of Al, O and Ti element. Temperature, control power and growth rate were investigated for their correlation on the growth process and crystal diameter profile. When the rotation speed was increased, Group A crystals showed an increase in density from 3.963 g cm-3 to 3.999 g cm-3. For group B crystals, the density decreased from 3.988 g cm-3 to 3.955 g cm-3 with increasing pulling rate. The porosity of the Group A crystals was found to decrease from 0.27% to 0.08% with increasing rotation speed. Group B crystals showed an increase in porosity from 0.09% to 0.44% with increasing pulling rate. From Vickers hardness test, the hardness of Group A crystals increased from 855 HV to 1698 HV with an increase in rotational speed. A decreased in hardness from 1439 HV to 845 HV was observed with increasing pulling rate for Group B crystals. The Young’s Modulus of Group A crystals increased from 1542 MPa to 2069 MPa with increasing rotation speed. However, when the pulling rate was increased for the Group B crystals, the Young’s Modulus was found to decrease from 2002 MPa to 1311 MPa. 2013-04 Thesis http://eprints.utm.my/id/eprint/50696/ http://eprints.utm.my/id/eprint/50696/25/MohammadNabilJainalMFS2013.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:89174 masters Universiti Teknologi Malaysia, Faculty of Science Faculty of Science
institution Universiti Teknologi Malaysia
collection UTM Institutional Repository
language English
topic QC Physics
spellingShingle QC Physics
Jainal, Mohammad Nabil
Effect of rotation speed and pulling rate on physical properties of titanium-doped sapphire single crystals
description Titanium-doped sapphire single crystals with 0.20 weight percentage of dopant were successfully produced by using the Automatic Diameter Control-Crystal Growth System based on the Czochralski technique. Group A crystals were produced at a constant pulling rate of 1.50 mm h-1 and a rotational speed (8-24) rpm and Group B crystal were produced at a constant rotational speed of 15 rpm and pulling rate (0.75-1.75) mm h-1. The presence of macroscopic defects such as gas bubbles and inclusions were found in the crystals produced at low rotation speed and at high pulling rate. XRD spectra of the crystals identified synthetic corundum as the main phase of the crystals and Al2TiO5 as the second phase. EDAX analysis showed the presence of Al, O and Ti element. Temperature, control power and growth rate were investigated for their correlation on the growth process and crystal diameter profile. When the rotation speed was increased, Group A crystals showed an increase in density from 3.963 g cm-3 to 3.999 g cm-3. For group B crystals, the density decreased from 3.988 g cm-3 to 3.955 g cm-3 with increasing pulling rate. The porosity of the Group A crystals was found to decrease from 0.27% to 0.08% with increasing rotation speed. Group B crystals showed an increase in porosity from 0.09% to 0.44% with increasing pulling rate. From Vickers hardness test, the hardness of Group A crystals increased from 855 HV to 1698 HV with an increase in rotational speed. A decreased in hardness from 1439 HV to 845 HV was observed with increasing pulling rate for Group B crystals. The Young’s Modulus of Group A crystals increased from 1542 MPa to 2069 MPa with increasing rotation speed. However, when the pulling rate was increased for the Group B crystals, the Young’s Modulus was found to decrease from 2002 MPa to 1311 MPa.
format Thesis
qualification_level Master's degree
author Jainal, Mohammad Nabil
author_facet Jainal, Mohammad Nabil
author_sort Jainal, Mohammad Nabil
title Effect of rotation speed and pulling rate on physical properties of titanium-doped sapphire single crystals
title_short Effect of rotation speed and pulling rate on physical properties of titanium-doped sapphire single crystals
title_full Effect of rotation speed and pulling rate on physical properties of titanium-doped sapphire single crystals
title_fullStr Effect of rotation speed and pulling rate on physical properties of titanium-doped sapphire single crystals
title_full_unstemmed Effect of rotation speed and pulling rate on physical properties of titanium-doped sapphire single crystals
title_sort effect of rotation speed and pulling rate on physical properties of titanium-doped sapphire single crystals
granting_institution Universiti Teknologi Malaysia, Faculty of Science
granting_department Faculty of Science
publishDate 2013
url http://eprints.utm.my/id/eprint/50696/25/MohammadNabilJainalMFS2013.pdf
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