Determination of the mechanical, thermal, transport, electronic and optoelectronics properties of AMoO4 (A=Ca, Sr, Ba, Pb), with and without oxygen vacancy, by ab-initio calculations

Pecinatto, Henrique; http://lattes.cnpq.br/1673661909466037

Tese

Determination of the mechanical, thermal, transport, electronic and optoelectronics properties of AMoO4 (A=Ca, Sr, Ba, Pb), with and without oxygen vacancy, by ab-initio calculations

Molybdates of the form AMoO 4 (A = Ca, Sr, Ba, Pb) are widely studied materials due to their photo-luminescence properties. In the present doctoral thesis, we analyze the effect of oxygen vacancies through density functional density (DFT) in these scheelite-type materials, aiming primarily at the...

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Autor principal:	Pecinatto, Henrique
Outros Autores:	http://lattes.cnpq.br/1673661909466037
Grau:	Tese
Idioma:	eng
Publicado em:	Universidade Federal do Amazonas 2023
Assuntos:	Ferromagnetismo Matéria condensada CIENCIAS EXATAS E DA TERRA: FISICA: FISICA DA MATERIA CONDENSADA Molybdate Oxygen vacancy Ferromagnetism Thermoelectric effect First- principles calculations
Acesso em linha:	https://tede.ufam.edu.br/handle/tede/9669

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spelling	oai:https:--tede.ufam.edu.br-handle-:tede-96692023-09-06T05:04:20Z Determination of the mechanical, thermal, transport, electronic and optoelectronics properties of AMoO4 (A=Ca, Sr, Ba, Pb), with and without oxygen vacancy, by ab-initio calculations Pecinatto, Henrique Frota, Hidembergue Orgozgoith da http://lattes.cnpq.br/1673661909466037 http://lattes.cnpq.br/5700103079488064 Ghosh, Angsula Galiceanu, Mircea Daniel Muniz, Edvani Curti Ferromagnetismo Matéria condensada CIENCIAS EXATAS E DA TERRA: FISICA: FISICA DA MATERIA CONDENSADA Molybdate Oxygen vacancy Ferromagnetism Thermoelectric effect First- principles calculations Molybdates of the form AMoO 4 (A = Ca, Sr, Ba, Pb) are widely studied materials due to their photo-luminescence properties. In the present doctoral thesis, we analyze the effect of oxygen vacancies through density functional density (DFT) in these scheelite-type materials, aiming primarily at the possible ferromagnetism induced due to this kind of defect. The spin- polarized band structure spectrum shows the appearance of narrow bands within the band gap for the spin-up channel. In BaMoO 4 -V O × , SrMoO 4 -V O × , and PbMoO 4 -V O × a resultant magnetic moment of 2µ B per cell is observed due to, the electrons once bonded with O being trapped by the 4d states in trigonal cluster MoO 3 , while in CaMoO 4 -V O × , the oxygen vacancy distort the lattice, so that crystal field splitting results in a low spin case with the resultant magnetic moment of 0.15µ B per cell. This study also provides a valuable tool for lowering the band gap in these materials, since the wide band gap has been recognized as a challenging factor for infrared and visible light photocatalysis performance. We calculated the mechanical properties from elastic constants such as bulk, shear, and Young modulus. In addition, Vicker’s hardness indicates that oxygen vacancy increases the hardness of these materials. For thermoelectric properties, the electrical conductivity is addressed to the n-type carrier and, allied with the low thermal conductivity (lattice + electronic) provided by phonon scattering, results in a high figure of merit for all defective scheelites. Molibdatos da forma AMoO 4 (A = Ca, Sr, Ba, Pb) são materiais amplamente estudados devido a suas propriedades de fotoluminescência. Na presente tese de doutorado, pretende- mos analisar o efeito de vacâncias de oxigênio através da teoria do funcional densidade (DFT) nestes materiais do tipo scheelita, visando principalmente o possível ferromagnetismo induzido devido a este tipo de defeito. O espectro da estrutura de bandas spin-polarizada mostra o apa- recimento de bandas estreitas dentro do gap do material para o canal spin-up. Foi observado no BaMoO 4 -V O × , SrMoO 4 -V O × , e PbMoO 4 -V O × um momento magnético resultante de 2µ B por célula, devido aos elétrons uma vez ligados ao O sendo presos pelos estados 4d no aglomerado trigonal MoO 3 , enquanto no CaMoO 4 -V O × , a vacância de oxigênio distorce a rede, de modo que o desdobramento do campo cristalino resulta em um caso de baixo spin com o campo magnético resultante de momento magnético igual a 0, 15µ B por célula. Este estudo também fornece uma ferramenta valiosa para diminuir o gap de energia nestes materiais, uma vez que o gap largo tem sido reconhecido como um fator desafiador para o desempenho de fotocatálise em luz in- fravermelha e visível. Calculamos as propriedades mecânicas, tais como o módulo de bulk, de cisalhamento e de Young, por meio das constantes elásticas. Além disso, a dureza de Vicker indica que a vacância de oxigênio aumenta a dureza desses materiais. Para as propriedades termoelétricas, a condutividade elétrica é endereçada ao portador do tipo n e, aliada a baixa condutividade térmica (rede + eletrônica) fornecida pelo espalhamento de fônons, resulta em um valor alto da figura de mérito para todas as scheelitas defeituosas. FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas 2023-09-05T19:19:15Z 2023-03-27 Tese PECINATTO, Henrique.Determination of the mechanical, thermal, transport, electronic and optoelectronics properties of AMoO4 (A=Ca, Sr, Ba, Pb), with and without oxygen vacancy, by ab-initio calculations. 2023. 129 f. Tese (Doutorado em Física) - Universidade Federal do Amazonas, Manaus (AM), 2023. https://tede.ufam.edu.br/handle/tede/9669 eng Acesso Aberto http://creativecommons.org/licenses/by/4.0/ application/pdf Universidade Federal do Amazonas Instituto de Ciências Exatas Brasil UFAM Programa de Pós-graduação em Física
institution	TEDE - Universidade Federal do Amazonas
collection	TEDE-UFAM
language	eng
topic	Ferromagnetismo Matéria condensada CIENCIAS EXATAS E DA TERRA: FISICA: FISICA DA MATERIA CONDENSADA Molybdate Oxygen vacancy Ferromagnetism Thermoelectric effect First- principles calculations
spellingShingle	Ferromagnetismo Matéria condensada CIENCIAS EXATAS E DA TERRA: FISICA: FISICA DA MATERIA CONDENSADA Molybdate Oxygen vacancy Ferromagnetism Thermoelectric effect First- principles calculations Pecinatto, Henrique Determination of the mechanical, thermal, transport, electronic and optoelectronics properties of AMoO4 (A=Ca, Sr, Ba, Pb), with and without oxygen vacancy, by ab-initio calculations
topic_facet	Ferromagnetismo Matéria condensada CIENCIAS EXATAS E DA TERRA: FISICA: FISICA DA MATERIA CONDENSADA Molybdate Oxygen vacancy Ferromagnetism Thermoelectric effect First- principles calculations
description	Molybdates of the form AMoO 4 (A = Ca, Sr, Ba, Pb) are widely studied materials due to their photo-luminescence properties. In the present doctoral thesis, we analyze the effect of oxygen vacancies through density functional density (DFT) in these scheelite-type materials, aiming primarily at the possible ferromagnetism induced due to this kind of defect. The spin- polarized band structure spectrum shows the appearance of narrow bands within the band gap for the spin-up channel. In BaMoO 4 -V O × , SrMoO 4 -V O × , and PbMoO 4 -V O × a resultant magnetic moment of 2µ B per cell is observed due to, the electrons once bonded with O being trapped by the 4d states in trigonal cluster MoO 3 , while in CaMoO 4 -V O × , the oxygen vacancy distort the lattice, so that crystal field splitting results in a low spin case with the resultant magnetic moment of 0.15µ B per cell. This study also provides a valuable tool for lowering the band gap in these materials, since the wide band gap has been recognized as a challenging factor for infrared and visible light photocatalysis performance. We calculated the mechanical properties from elastic constants such as bulk, shear, and Young modulus. In addition, Vicker’s hardness indicates that oxygen vacancy increases the hardness of these materials. For thermoelectric properties, the electrical conductivity is addressed to the n-type carrier and, allied with the low thermal conductivity (lattice + electronic) provided by phonon scattering, results in a high figure of merit for all defective scheelites.
author_additional	Frota, Hidembergue Orgozgoith da
author_additionalStr	Frota, Hidembergue Orgozgoith da
format	Tese
author	Pecinatto, Henrique
author2	http://lattes.cnpq.br/1673661909466037
author2Str	http://lattes.cnpq.br/1673661909466037
title	Determination of the mechanical, thermal, transport, electronic and optoelectronics properties of AMoO4 (A=Ca, Sr, Ba, Pb), with and without oxygen vacancy, by ab-initio calculations
title_short	Determination of the mechanical, thermal, transport, electronic and optoelectronics properties of AMoO4 (A=Ca, Sr, Ba, Pb), with and without oxygen vacancy, by ab-initio calculations
title_full	Determination of the mechanical, thermal, transport, electronic and optoelectronics properties of AMoO4 (A=Ca, Sr, Ba, Pb), with and without oxygen vacancy, by ab-initio calculations
title_fullStr	Determination of the mechanical, thermal, transport, electronic and optoelectronics properties of AMoO4 (A=Ca, Sr, Ba, Pb), with and without oxygen vacancy, by ab-initio calculations
title_full_unstemmed	Determination of the mechanical, thermal, transport, electronic and optoelectronics properties of AMoO4 (A=Ca, Sr, Ba, Pb), with and without oxygen vacancy, by ab-initio calculations
title_sort	determination of the mechanical, thermal, transport, electronic and optoelectronics properties of amoo4 (a=ca, sr, ba, pb), with and without oxygen vacancy, by ab-initio calculations
publisher	Universidade Federal do Amazonas
publishDate	2023
url	https://tede.ufam.edu.br/handle/tede/9669
_version_	1831970226877497344
score	11.753896

Determination of the mechanical, thermal, transport, electronic and optoelectronics properties of AMoO4 (A=Ca, Sr, Ba, Pb), with and without oxygen vacancy, by ab-initio calculations

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