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Chiappim W, Testoni G, Miranda F, Fraga M, Furlan H, Saravia DA, Sobrinho ADS, Petraconi G, Maciel H, Pessoa R. Effect of Plasma-Enhanced Atomic Layer Deposition on Oxygen Overabundance and Its Influence on the Morphological, Optical, Structural, and Mechanical Properties of Al-Doped TiO 2 Coating. MICROMACHINES 2021; 12:mi12060588. [PMID: 34063804 PMCID: PMC8223979 DOI: 10.3390/mi12060588] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 05/19/2021] [Indexed: 11/16/2022]
Abstract
The chemical, structural, morphological, and optical properties of Al-doped TiO2 thin films, called TiO2/Al2O3 nanolaminates, grown by plasma-enhanced atomic layer deposition (PEALD) on p-type Si <100> and commercial SLG glass were discussed. High-quality PEALD TiO2/Al2O3 nanolaminates were produced in the amorphous and crystalline phases. All crystalline nanolaminates have an overabundance of oxygen, while amorphous ones lack oxygen. The superabundance of oxygen on the crystalline film surface was illustrated by a schematic representation that described this phenomenon observed for PEALD TiO2/Al2O3 nanolaminates. The transition from crystalline to amorphous phase increased the surface hardness and the optical gap and decreased the refractive index. Therefore, the doping effect of TiO2 by the insertion of Al2O3 monolayers showed that it is possible to adjust different parameters of the thin-film material and to control, for example, the mobility of the hole-electron pair in the metal-insulator-devices semiconductors, corrosion protection, and optical properties, which are crucial for application in a wide range of technological areas, such as those used to manufacture fluorescence biosensors, photodetectors, and solar cells, among other devices.
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Affiliation(s)
- William Chiappim
- Laboratório de Plasmas e Processos, Instituto Tecnológico de Aeronáutica, Praça Marechal Eduardo Gomes 50, São José dos Campos 12228-900, Brazil; (G.T.); (F.M.); (A.d.S.S.); (G.P.); (H.M.)
- i3N, Departamento de Física, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
- Correspondence: (W.C.); (M.F.); (R.P.); Tel.: +55-12-3947-5785 (R.P.)
| | - Giorgio Testoni
- Laboratório de Plasmas e Processos, Instituto Tecnológico de Aeronáutica, Praça Marechal Eduardo Gomes 50, São José dos Campos 12228-900, Brazil; (G.T.); (F.M.); (A.d.S.S.); (G.P.); (H.M.)
| | - Felipe Miranda
- Laboratório de Plasmas e Processos, Instituto Tecnológico de Aeronáutica, Praça Marechal Eduardo Gomes 50, São José dos Campos 12228-900, Brazil; (G.T.); (F.M.); (A.d.S.S.); (G.P.); (H.M.)
| | - Mariana Fraga
- Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, Rua Talim 330, São José dos Campos 12231-280, Brazil
- Correspondence: (W.C.); (M.F.); (R.P.); Tel.: +55-12-3947-5785 (R.P.)
| | - Humber Furlan
- Centro Estadual de Educação Tecnológica Paula Souza, Programa de Pós-Graduação em Gestão e Tecnologia em Sistemas Produtivos, São Paulo 01124-010, Brazil;
| | | | - Argemiro da Silva Sobrinho
- Laboratório de Plasmas e Processos, Instituto Tecnológico de Aeronáutica, Praça Marechal Eduardo Gomes 50, São José dos Campos 12228-900, Brazil; (G.T.); (F.M.); (A.d.S.S.); (G.P.); (H.M.)
| | - Gilberto Petraconi
- Laboratório de Plasmas e Processos, Instituto Tecnológico de Aeronáutica, Praça Marechal Eduardo Gomes 50, São José dos Campos 12228-900, Brazil; (G.T.); (F.M.); (A.d.S.S.); (G.P.); (H.M.)
| | - Homero Maciel
- Laboratório de Plasmas e Processos, Instituto Tecnológico de Aeronáutica, Praça Marechal Eduardo Gomes 50, São José dos Campos 12228-900, Brazil; (G.T.); (F.M.); (A.d.S.S.); (G.P.); (H.M.)
- Instituto Científico e Tecnológico, Universidade Brasil, São Paulo 08230-030, Brazil
| | - Rodrigo Pessoa
- Laboratório de Plasmas e Processos, Instituto Tecnológico de Aeronáutica, Praça Marechal Eduardo Gomes 50, São José dos Campos 12228-900, Brazil; (G.T.); (F.M.); (A.d.S.S.); (G.P.); (H.M.)
- Correspondence: (W.C.); (M.F.); (R.P.); Tel.: +55-12-3947-5785 (R.P.)
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Al-Baradi AM, Rimmer S, Carter SR, de Silva JP, King SM, Maccarini M, Farago B, Noirez L, Geoghegan M. Temperature-dependent structure and dynamics of highly-branched poly(N-isopropylacrylamide) in aqueous solution. SOFT MATTER 2018; 14:1482-1491. [PMID: 29400392 DOI: 10.1039/c7sm02330h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Small-angle neutron scattering (SANS) and neutron spin-echo (NSE) have been used to investigate the temperature-dependent solution behaviour of highly-branched poly(N-isopropylacrylamide) (HB-PNIPAM). SANS experiments have shown that water is a good solvent for both HB-PNIPAM and a linear PNIPAM control at low temperatures where the small angle scattering is described by a single correlation length model. Increasing the temperature leads to a gradual collapse of HB-PNIPAM until above the lower critical solution temperature (LCST), at which point aggregation occurs, forming disperse spherical particles of up to 60 nm in diameter, independent of the degree of branching. However, SANS from linear PNIPAM above the LCST is described by a model that combines particulate structure and a contribution from solvated chains. NSE was used to study the internal and translational solution dynamics of HB-PNIPAM chains below the LCST. Internal HB-PNIPAM dynamics is described well by the Rouse model for non-entangled chains.
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Affiliation(s)
- Ateyyah M Al-Baradi
- Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield S3 7RH, UK.
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Vollet DR, Awano CM, de Vicente FS, Ruiz AI, Donatti DA. Temperature effect on the structure and formation kinetics of vinyltriethoxysilane-derived organic/silica hybrids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:10986-10992. [PMID: 21736335 DOI: 10.1021/la200978y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The structure and formation kinetics of organic/silica hybrid species prepared from acid hydrolysis of vinyltriethoxisilane has been studied in situ by small-angle X-ray scattering (SAXS) at 298, 318, and 333 K in a strongly basic step of the process. The evolution of the SAXS intensity is compatible with the formation of linear chains which grow, coil, and branch to form polymeric macromolecules in solution. The SAXS data were analyzed by the scattering from a persistent chain model for polymeric macromolecules in solution using a modified branching Sharp and Bloomfield global function, which incorporates a branching probability typical of randomly and nonrandomly branched polycondensates, and in a particular case, it is also valid for polydisperse coils of linear chains. Growth of linear chains and coiling dominate the process up to the formation of likely monodisperse Gaussian coils or polydisperse coils of linear chains. The link probability to form a branching point is increased with time to form nonrandomly branched polycondensates in solution. The kinetics of the process is accelerated with temperature, but all the curves formed by the time evolution of the structural parameters in all temperatures can correspondingly be matched on a unique curve by using an appropriate time scaling factor. The activation energy of the process was evaluated as ΔE = 21 ± 1 kJ/mol. The characteristics of the kinetics are in favor of a complex overall mechanism controlled by both condensation reactions and dynamical forces driven by interfacial energy up to the final structure development of the hybrids.
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Affiliation(s)
- Dimas R Vollet
- Departamento de Física, Instituto de Geociências e Ciências Exatas, UNESP-Universidade Estadual Paulista, Cx.P. 178, 13500-970 Rio Claro (SP), Brazil.
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