Samuel Silva dos Santos

Pós-doutorado

Formação complementar

Idiomas

Projetos de pesquisa

• 2016 - Atual

  Entendimento e desenho de novos materiais multifuncionais, Descrição: Tirando proveito da complementariedade entre as equipes portuguesa e brasileira, o trabalho será dividido de forma que: - na USP, os novos sistemas desenhados, suas propriedades elétricas e magnéticas, serão investigadas através de simulações computacionais e cálculos de estrutura eletrônica ab- initio dentro da Teoria do Funcional da Densidade ( DFT). Estudos de deslocamentos iônicos e suas contribuições para o Gradiente de Campo elétrico no núcleo ( propriedade hiperfina elétrica) serão perseguidas; - na UP, estabilidades de fases de novos compostos serão estudadas por diferentes rotas de síntese química. Uma caracterização geral dará acesso à qualidade da amostra e inspeção de suas propriedades físicas. Sistemas promissores serão estudados em detalhe. Em particular, serão metodicamente analisados sobre transições de fases induzidas por diferentes estímulos externos tais como temperatura e campos elétricos ou magnéticos. Desta forma, estudos experimentais/teóricos complementares serão realizados levando acesso a informações locais/macroscópicas, levando ao entendimento dos mecanismos físicos envolvidos no efeito magnetoelétrico(ME), assistindo assim no desenvolvimento de novos materiais MEs de alto desempenho a temperatura ambiente.. , Situação: Em andamento; Natureza: Pesquisa. , Integrantes: Samuel Silva dos Santos - Integrante / Helena Maria Petrilli - Coordenador / João Pedro Esteves de Araújo - Integrante / Armandina Maria Lima Lopes - Integrante / Lucy Vitoria Credidio Assali - Integrante.

Projetos de desenvolvimento

• 2021 - Atual

  Natural Layered Perovskite Oxide Engineering for Green Technologies, Descrição: An important challenge of this century, within the goals of the 2030 Agenda for Sustainable Development, is to search for new materials allowing the development of novel sources for sustainable energy harvesting. In fact, lead-free photovoltaics (PV) and photoelectrochemical (PEC) cells, applied for water splitting and Hydrogen production, comply with these aforementioned challenges. Perovskite oxides (PVO), such as those with ABO3 stoichiometry (A=alkaline or rare?earth metals; B=transition metals) are an important class of functional materials, due to their structural and compositional flexibility, providing a direct impact to the proposed technologies. However, to enhance the capabilities of such systems it is necessary to guide and tune the design for achieving maximum efficiencies. For example, through substitutional doping with cations that present different oxidation states and differ in ionic radii, lattice distortions may occur enabling structural phase transitions. These variations cause a direct impact to the crystal-field splitting of the PVO, thus altering the opto-electronic properties of the system. Band gap engineering in PVO systems may allow for the tuning of the photogenerated charge carriers through variation of the absorption coefficients and electron-hole diffusion lengths. This project aims the search for promising perovskite systems, which evidence efficient optical and electronic properties for applications to environment-friendly PEC and PV devices.. , Situação: Em andamento; Natureza: Desenvolvimento. , Alunos envolvidos: Doutorado: (3) . , Integrantes: Samuel Silva dos Santos - Integrante / João Pedro Esteves de Araújo - Coordenador / Estelina Lora da Silva - Integrante.

• 2021 - Atual

  Hybrid Improper Ferroelectricity in AA'Fe2O6 Double Perovskite, Descrição: The coupling of electrical and magnetic properties gives rise to new mechanisms to design novel technological architectures and new functionalities. Negative thermal expansion, for example, greatly expands the application potential of multiferroics. In addition, unraveling the ferroelectricity mechanism provides insights into new physical phenomena. Naturally layered structures offer an inspiring alternative route to achieve non-expensive and high-performance room temperature multiferroics. Here, we envisage the development of Naturally Layered Perovskites (NLP) like structures, aiming for new functional materials. These new materials apparently presenting hybrid improper ferroelectricity (HIF) are being reported at a fast pace. We will combine state-of-the-art theoretical ab initio methods, by Density Functional Theory (DFT), with experimental techniques to synthesize new NLP, providing paths to produce new multifunctional efficient materials. The present project focuses on the study of materials that exhibit HIF, more specifically, on the AA'Fe2O6 double perovskite and on the incorporation of several cations, such as Y, Gd, Lu, and Sc at sites A and A'. This project is part of an ongoing project called Functional Lattice Instabilities in Naturally Layered Perovskites (FLIP). FLIP is an international collaboration that aims to produce, model, and probe Naturally Layered Perovskites, providing new efficient materials for sustainable energy conversion.. , Situação: Em andamento; Natureza: Desenvolvimento. , Alunos envolvidos: Doutorado: (1) . , Integrantes: Samuel Silva dos Santos - Coordenador.

• 2021 - Atual

  Hybrid Improper Ferroelectricity in AA'Fe2O6 Double Perovskite, Descrição: The coupling of electrical and magnetic properties gives rise to new mechanisms to design novel technological architectures and new functionalities. Negative thermal expansion, for example, greatly expands the application potential of multiferroics. In addition, unraveling the ferroelectricity mechanism provides insights into new physical phenomena. Naturally layered structures offer an inspiring alternative route to achieve non-expensive and high-performance room temperature multiferroics. Here, we envisage the development of Naturally Layered Perovskites (NLP) like structures, aiming for new functional materials. These new materials apparently presenting hybrid improper ferroelectricity (HIF) are being reported at a fast pace. We will combine state-of-the-art theoretical ab initio methods, by Density Functional Theory (DFT), with experimental techniques to synthesize new NLP, providing paths to produce new multifunctional efficient materials. The present project focuses on the study of materials that exhibit HIF, more specifically, on the AA'Fe2O6 double perovskite and on the incorporation of several cations, such as Y, Gd, Lu, and Sc at sites A and A'. This project is part of an ongoing project called Functional Lattice Instabilities in Naturally Layered Perovskites (FLIP). FLIP is an international collaboration that aims to produce, model, and probe Naturally Layered Perovskites, providing new efficient materials for sustainable energy conversion.. , Situação: Em andamento; Natureza: Desenvolvimento. , Alunos envolvidos: Doutorado: (1) . , Integrantes: Samuel Silva dos Santos - Coordenador.

• 2021 - Atual

  Natural Layered Perovskite Oxide Engineering for Green Technologies, Descrição: An important challenge of this century, within the goals of the 2030 Agenda for Sustainable Development, is to search for new materials allowing the development of novel sources for sustainable energy harvesting. In fact, lead-free photovoltaics (PV) and photoelectrochemical (PEC) cells, applied for water splitting and Hydrogen production, comply with these aforementioned challenges. Perovskite oxides (PVO), such as those with ABO3 stoichiometry (A=alkaline or rare?earth metals; B=transition metals) are an important class of functional materials, due to their structural and compositional flexibility, providing a direct impact to the proposed technologies. However, to enhance the capabilities of such systems it is necessary to guide and tune the design for achieving maximum efficiencies. For example, through substitutional doping with cations that present different oxidation states and differ in ionic radii, lattice distortions may occur enabling structural phase transitions. These variations cause a direct impact to the crystal-field splitting of the PVO, thus altering the opto-electronic properties of the system. Band gap engineering in PVO systems may allow for the tuning of the photogenerated charge carriers through variation of the absorption coefficients and electron-hole diffusion lengths. This project aims the search for promising perovskite systems, which evidence efficient optical and electronic properties for applications to environment-friendly PEC and PV devices.. , Situação: Em andamento; Natureza: Desenvolvimento. , Alunos envolvidos: Doutorado: (3) . , Integrantes: Samuel Silva dos Santos - Integrante / João Pedro Esteves de Araújo - Coordenador / Estelina Lora da Silva - Integrante.

• 2021 - Atual

  Hybrid Improper Ferroelectricity in AA'Fe2O6 Double Perovskite, Descrição: The coupling of electrical and magnetic properties gives rise to new mechanisms to design novel technological architectures and new functionalities. Negative thermal expansion, for example, greatly expands the application potential of multiferroics. In addition, unraveling the ferroelectricity mechanism provides insights into new physical phenomena. Naturally layered structures offer an inspiring alternative route to achieve non-expensive and high-performance room temperature multiferroics. Here, we envisage the development of Naturally Layered Perovskites (NLP) like structures, aiming for new functional materials. These new materials apparently presenting hybrid improper ferroelectricity (HIF) are being reported at a fast pace. We will combine state-of-the-art theoretical ab initio methods, by Density Functional Theory (DFT), with experimental techniques to synthesize new NLP, providing paths to produce new multifunctional efficient materials. The present project focuses on the study of materials that exhibit HIF, more specifically, on the AA'Fe2O6 double perovskite and on the incorporation of several cations, such as Y, Gd, Lu, and Sc at sites A and A'. This project is part of an ongoing project called Functional Lattice Instabilities in Naturally Layered Perovskites (FLIP). FLIP is an international collaboration that aims to produce, model, and probe Naturally Layered Perovskites, providing new efficient materials for sustainable energy conversion.. , Situação: Em andamento; Natureza: Desenvolvimento. , Alunos envolvidos: Doutorado: (1) . , Integrantes: Samuel Silva dos Santos - Coordenador.

• 2021 - Atual

  Natural Layered Perovskite Oxide Engineering for Green Technologies, Descrição: An important challenge of this century, within the goals of the 2030 Agenda for Sustainable Development, is to search for new materials allowing the development of novel sources for sustainable energy harvesting. In fact, lead-free photovoltaics (PV) and photoelectrochemical (PEC) cells, applied for water splitting and Hydrogen production, comply with these aforementioned challenges. Perovskite oxides (PVO), such as those with ABO3 stoichiometry (A=alkaline or rare?earth metals; B=transition metals) are an important class of functional materials, due to their structural and compositional flexibility, providing a direct impact to the proposed technologies. However, to enhance the capabilities of such systems it is necessary to guide and tune the design for achieving maximum efficiencies. For example, through substitutional doping with cations that present different oxidation states and differ in ionic radii, lattice distortions may occur enabling structural phase transitions. These variations cause a direct impact to the crystal-field splitting of the PVO, thus altering the opto-electronic properties of the system. Band gap engineering in PVO systems may allow for the tuning of the photogenerated charge carriers through variation of the absorption coefficients and electron-hole diffusion lengths. This project aims the search for promising perovskite systems, which evidence efficient optical and electronic properties for applications to environment-friendly PEC and PV devices.. , Situação: Em andamento; Natureza: Desenvolvimento. , Alunos envolvidos: Doutorado: (3) . , Integrantes: Samuel Silva dos Santos - Integrante / João Pedro Esteves de Araújo - Coordenador / Estelina Lora da Silva - Integrante.

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