Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
Browse
Search Results
- Investigation of structural phase transitions in ferroelectric BaTiO3 thin films from composite solutions(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-06) Lugo Martínez, Enrique; Ulloa Castillo, Nicolás Antonio; emipsanchez; De León Covián, Lina Melva; Morales Luna, Michael; Segura Cárdenas, Emmanuel; Melo Máximo, Dulce Viridiana; School of Engineering and Sciences; Campus Monterrey; Rodríguez Aranda, Ma. del CarmenIn this study, we investigate the synthesis and structural phase evolution of barium titanate (BaTiO3) thin films produced using a polymer-assisted sol-gel method. This innovative approach integrates the advantages of polymer-based solutions with the sol-gel method. The unique viscoelastic properties of polyvinylpyrrolidone (PVP) enhance the development of homogenous BaTiO3 thin films with controlled microstructures. To optimize these properties, we formulated composite solutions by varying the concentrations of PVP in conjunction with the sol-gel precursor. The composite precursor solutions were deposited onto quartz substrates via the spin-coating technique and subsequently sintered at temperatures of 400, 500, 700, and 900°C to promote optimal BaTiO3 crystallization. Structural phase characterization was performed using X-ray diffraction (XRD), infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). TGA data indicated significant weight loss due to moisture evaporation occurring around 200°C, followed by PVP decomposition at approximately 430°C, with a flash point thermal event occurring at around 450°C. The monitoring of structural phase transitions throughout the sintering process revealed a transformation from an amorphous phase to crystalline barium carbonate (BaCO3), ultimately leading to the development of the ferroelectric BaTiO3 phase. The BaCO3 phase was identified at 400°C and gradually decomposed at 500, 700 and 900°C, while the BaTiO3 phase emerged at 700°C and achieved full consolidation above 900°C. The morphological evolution was monitored through scanning electron microscopy (SEM), and the chemical composition was analyzed using energy dispersive spectroscopy (EDS) for elemental mapping of Ba, Ti, C and O. Notably, films with higher concentrations of the polymer exhibited an increased content of BaCO3. The structural and electronic properties of the obtained phases during sintering were evaluated through photoluminescence (PL). This revealed defect-mediated emissions that intensified and exhibited a blue shift with increased sintering temperature. The findings of this research highlight the potential of the polymer-assisted sol-gel method as an effective route for synthesizing ferroelectric thin-film materials with controlled microstructures. This study provides valuable insights into the synthesis and characterization of ferroelectric materials and establishes a novel methodology for optimizing thin film properties that can be used in piezoelectric and microelectronic applications.
- Development of a piezoelectric smart device with fiber meshes elaborated by Forcespinning™(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-06-14) Aguirre Corona, Renato Wenceslao; ELIAS ZUÑIGA, ALEX; 2019150; Elías Zúñiga, Alex; puelquio, emipsanchez; Olvera Trejo, Daniel; Martínez Romero, Oscar; Escuela de Ingeniería y Ciencias; Campus Monterrey; Del Ángel Sánchez, KarinaA novel approach was used in this thesis project. BaTiO3 nanoparticles named as BTO nanoparticles were synthesized in the laboratory and commercial graphene named as G are used as fillers in Polyvinylidene Fluoride named as PVDF for the formation of polymeric meshes for the development of piezoelectric devices. Piezoelectric fiber meshes from different materials as: PVDF, BTO/PVDF, G/PVDF, BTO/G/PVDF are done varying the concentration of the fillers to evaluate the materials. The fiber meshes were fabricated in the Forcespinning™ technique and were characterized using different techniques. Scanning Electron Microscopy was used to obtain the morphology and chemical composition by Energy Dispersive Spectroscopy(EDS), Fourier Transformed Infrared Spectroscopy (FTIR) was done for the identification of the phase composition of the material, Thermogravimetric Analysis allows the obtention of the maximum temperature of degradation to identify the materials with more thermal stability and X-ray Diffraction confirmed us the presence of the planes of the β phase in the fiber meshes and in the BTO the planes that are in concordance to the crystallographic card 96-150-7758. For the characterization of the piezoelectric devices an Impact tester was used with a multimeter to record the voltage generated by all the samples. Where the mean maximum voltage generated for the A2 device is 35.77 Voc, the best device with only BTO as filler, while A3, A4, A6 and A7 samples are samples where G is used with a bad performance. The devices developed can be used for different applications as sensors or nanogenerators, showing a promising performance. Piezoelectric devices are of interest by the generation of voltage from sources that were not used before, therefore producing energy from sustainable alternatives, offering an option for remote self-powered sensors.
- Development of a piezoelectric smart device with fiber meshes elaborated by Forcespinning™(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-06-14) Aguirre Corona, Renato Wenceslao; ELIAS ZUÑIGA, ALEX; 19150; Elías Zúñiga, Alex; tolmquevedo/mscuervo; Rodríguez Salinas, Juan José; Martínez Romero, Oscar; Olvera Trejo, Daniel; Escuela de Ingeniería y Ciencias; Campus Monterrey; Del Ángel Sánchez, KarinaA novel approach was used in this thesis project. BaTiO3 nanoparticles named as BTO nanoparticles were synthesized in the laboratory and commercial graphene named as G are used as fillers in Polyvinylidene Fluoride named as PVDF for the formation of polymeric meshes for the development of piezoelectric devices. Piezoelectric fiber meshes from different materials as: PVDF, BTO/PVDF, G/PVDF, BTO/G/PVDF are done varying the concentration of the fillers to evaluate the materials. The fiber meshes were fabricated in the Forcespinning™ technique and were characterized using different techniques. Scanning Electron Microscopy was used to obtain the morphology and chemical composition by Energy Dispersive Spectroscopy(EDS), Fourier Transformed Infrared Spectroscopy (FTIR) was done for the identification of the phase composition of the material, Thermogravimetric Analysis allows the obtention of the maximum temperature of degradation to identify the materials with more thermal stability and X-ray Diffraction confirmed us the presence of the planes of the β phase in the fiber meshes and in the BTO the planes that are in concordance to the crystallographic card 96-150-7758. For the characterization of the piezoelectric devices an Impact tester was used with a multimeter to record the voltage generated by all the samples. Where the mean maximum voltage generated for the A2 device is 35.77 Voc, the best device with only BTO as filler, while A3, A4, A6 and A7 samples are samples where G is used with a bad performance. The devices developed can be used for different applications as sensors or nanogenerators, showing a promising performance. Piezoelectric devices are of interest by the generation of voltage from sources that were not used before, therefore producing energy from sustainable alternatives, offering an option for remote self-powered sensors.