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Ab-initio computation of electronic...

Nwigboji, Ifeanyi Humphrey.

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Ab-initio computation of electronic, and transport properties of wurtzite aluminum nitride (W-AlN) and microwave absorption properties of multi-walled carbon nanotubes (outer diameter 20-30 nanometers)-epoxy composites.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Ab-initio computation of electronic, and transport properties of wurtzite aluminum nitride (W-AlN) and microwave absorption properties of multi-walled carbon nanotubes (outer diameter 20-30 nanometers)-epoxy composites./
Author:	Nwigboji, Ifeanyi Humphrey.
Description:	77 p.
Notes:	Source: Masters Abstracts International, Volume: 54-04.
Contained By:	Masters Abstracts International54-04(E).
Subject:	Condensed matter physics. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=1586793
ISBN:	9781321692761

Ab-initio computation of electronic, and transport properties of wurtzite aluminum nitride (W-AlN) and microwave absorption properties of multi-walled carbon nanotubes (outer diameter 20-30 nanometers)-epoxy composites.
Nwigboji, Ifeanyi Humphrey.

Ab-initio computation of electronic, and transport properties of wurtzite aluminum nitride (W-AlN) and microwave absorption properties of multi-walled carbon nanotubes (outer diameter 20-30 nanometers)-epoxy composites. - 77 p.

Source: Masters Abstracts International, Volume: 54-04.

Thesis (M.S.)--Southern University and Agricultural and Mechanical College, 2015.

In Section I, We report findings from several ab-initio, self-consistent calculations of electronic and transport properties of wurtzite aluminum nitride (w-AlN). Our calculations utilized a local density approximation (LDA) potential and the linear combination of Gaussian orbitals (LCGO). Unlike some other density functional theory (DFT) calculations, we employed the Bagayoko, Zhao, and Williams' method, enhanced by Ekuma and Franklin (BZW-EF). The BZW-EF method verifiably leads to the minima of the occupied energies; these minima, the low laying unoccupied energies, and related wave functions provide the most variationally and physically valid density functional theory (DFT) description of the ground states of materials under study. With multiple oxidation states of Al (Al3+ to Al) and the availability of N3- to N, the BZW-EF method required several sets of self-consistent calculations with different ionic species as input. The binding energy for (Al3+ & N3-) as input was 1.5 eV larger in magnitude than those for other input choices; the results discussed here are those from the calculation that led to the absolute minima of the occupied energies with this input. Our calculated, direct band gap for w-AlN, at the Gamma point, is 6.28 eV, in excellent agreement with the 6.28 eV experimental value at 5K. We discuss the bands, total and partial densities of states, and calculated, effective masses.

ISBN: 9781321692761Subjects--Topical Terms:

3173567
Condensed matter physics.

Ab-initio computation of electronic, and transport properties of wurtzite aluminum nitride (W-AlN) and microwave absorption properties of multi-walled carbon nanotubes (outer diameter 20-30 nanometers)-epoxy composites.
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100 1 $a Nwigboji, Ifeanyi Humphrey. $3 3184132
245 1 0 $a Ab-initio computation of electronic, and transport properties of wurtzite aluminum nitride (W-AlN) and microwave absorption properties of multi-walled carbon nanotubes (outer diameter 20-30 nanometers)-epoxy composites.
300 $a 77 p.
500 $a Source: Masters Abstracts International, Volume: 54-04.
500 $a Adviser: Diola Bagayoko.
502 $a Thesis (M.S.)--Southern University and Agricultural and Mechanical College, 2015.
520 $a In Section I, We report findings from several ab-initio, self-consistent calculations of electronic and transport properties of wurtzite aluminum nitride (w-AlN). Our calculations utilized a local density approximation (LDA) potential and the linear combination of Gaussian orbitals (LCGO). Unlike some other density functional theory (DFT) calculations, we employed the Bagayoko, Zhao, and Williams' method, enhanced by Ekuma and Franklin (BZW-EF). The BZW-EF method verifiably leads to the minima of the occupied energies; these minima, the low laying unoccupied energies, and related wave functions provide the most variationally and physically valid density functional theory (DFT) description of the ground states of materials under study. With multiple oxidation states of Al (Al3+ to Al) and the availability of N3- to N, the BZW-EF method required several sets of self-consistent calculations with different ionic species as input. The binding energy for (Al3+ & N3-) as input was 1.5 eV larger in magnitude than those for other input choices; the results discussed here are those from the calculation that led to the absolute minima of the occupied energies with this input. Our calculated, direct band gap for w-AlN, at the Gamma point, is 6.28 eV, in excellent agreement with the 6.28 eV experimental value at 5K. We discuss the bands, total and partial densities of states, and calculated, effective masses.
520 $a In section II, multi-walled carbon nanotubes (MWCNTs)-epoxy composites with MWCNTs of outer diameters (OD) of 20-30nm was fabricated. The MWCNT loadings in the composites were controlled from 1-10 wt. %. An Agilent PNA Network analyzer was utilized in the measurements of microwave absorption (MA) properties of these MWCNTs-epoxy composites over a wide frequency range of 1-26.5GHz.The measurement results showed that MA strongly depends on MWCNTs loadings in the composites. In addition, the microwave reflection, transmission, and dielectric permittivity of the MWCNTs-epoxy composites are also investigated. The composite with 8 wt. % MWCNT loading show high microwave absorption as well as low reflection and transmission. These MWCNTs-epoxy composites with 8-10 wt.% MWCNT loadings show a significant potential for microwave technology applications.
590 $a School code: 1218.
650 4 $a Condensed matter physics. $3 3173567
650 4 $a Materials science. $3 543314
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690 $a 0794
710 2 $a Southern University and Agricultural and Mechanical College. $b Physics. $3 3184133
773 0 $t Masters Abstracts International $g 54-04(E).
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791 $a M.S.
792 $a 2015
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=1586793