Presentaciones

In recent years, a series of very high-quality peak-fitting analyses of X-ray photoelectron spectroscopy (XPS) data have been reported. These works, which were especially focused on the accurate fitting of complex structures of the 2p photoelectron spectra of the 4th period transition metals, also showed the need to use physical parameters in the fitting process, adequate line shapes, the consideration of both photoemission lines, and especially a proper modeling of the background. The reports also showed the robustness of the proposed fits by successfully assessing the chemical composition. For the special case of the Cu2p photoelectron spectra, there is no direct way to differentiate between the signal contribution of Cu0 and Cu1+ since the shape of the spectra are almost identical. Some works use the Auger parameter to determine this difference in chemical species, however, in thin films, the shape and the Auger parameter cannot properly be used, because as it happens in the Cu2p spectra, the Cu1+ Auger signal is also identical to metallic copper Auger signal. Ultra-pure copper films were deposited by sublimation in ultrahigh vacuum, which guaranteed films were free of carbon and oxygen. Subsequently, exposures were made in a controlled atmosphere of ultra-pure oxygen for 10, 100, 1000 and 10,000 mega Langmuir (ML), obtaining high-resolution spectra of Cu for the first stages of oxidation. For the spectrum of metallic copper, it was possible to assess the Lorentzian width of both branches as a function of oxygen exposure. We found that, while the width of the 3/2 branch is the same for the Cu0 and Cu1+ cases, the Lorentzian width of the 1/2 branch evolves from 1.34 eV (for Cu0) to 1.01 eV for Cu1+. This modulation allows, employing XPS data, for the quantification of the Cu1+ when both Cu0 and Cu1+ are present.

This work was partially financed by Proyecto Fronteras 58518, Conacyt, Mexico.

SMCyTSM 2022-Puerto Vallarta

En el presente trabajo se fabricaron membranas de poliuretano utilizando un poliol, isocianato y reticulante, comerciales.  La síntesis de los poliuretanos se llevó a cabo con un diseño de experimentos para mezclas, utilizando un modelo simplex con centroide de 10 experimentos y dos réplicas.  De experimentos previos se consideraron niveles de precursores entre 40 y 60% de poliol e isocianato, y entre 5 y 20% de reticulante.  Los precursores fueron mezclados por medio de un equipo B&D a 200rpm por 30 s, hasta que inició el proceso de cremado. Posteriormente, se depositaron en una prensa diseñada para este trabajo, donde se les aplicó una carga de 800N.  Después de 5 minutos de curación, las membranas se retiraron de la prensa y se analizaron con un microscopio metalográfico hasta un aumento de 100X.  

AMIDIQ 2022-Puerto Vallarta

En el presente trabajo se muestra la metodología para la obtención de ortesis plantares impresas en nylon reforzado con fibra de carbono utilizando estructuras de Voronoi.  Se obtuvieron modelos plantares de la curvatura en estado de relajación y en un estado de compresión estática de personas diagnosticadas con pie plano por medio de un escáner 3D.   Estos modelos fueron procesados en un software CAD para la obtención de modelos de ortesis plantares que corrigieran la curvatura del pie.  Posteriormente, los modelos fueron procesados para la generación de estructuras Voronoi, realizando variaciones en la densidad de puntos, espesor de la estructura y curvatura.  Los mejores modelos obtenidos fueron impresos en una matriz de nylon reforzado con fibra de carbono 

AMIDIQ 2021-Evento Virtual

The use of high mobility substrates such as InGaAs as a semiconductor for the manufacturing of CMOS devices is of great relevance for THz applications. The unwanted migration of substrate species through the dielectric layer might constitute a failure mechanism for this type of devices. Nitridation is a process commonly used in manufacturing silicon-based CMOS devices. This process limits the migration of certain species, such as boron and phosphorus, through the silicon oxide layer.5 In this work we reports the nitridation degree, carried out through remote plasma processing (LITMAS), of 2 nm films of silicon oxide and hafnium oxide. The plasma power was varied between 500 and 2500W and the substrate temperature between 200 and 500°C. The working pressure and nitrogen flow were kept at 5.0×10‑2 Torr and 110 sccm, respectively. The nitridation of silica saturates at a 1:3 N to O ratio.6 This condition was obtained at 2,500W and 400°C after 10 min. The nitridation of hafnia, under the same parameters only reached a 1:12 N to O ratio. We are exploring the processing conditions for substitutional nitridation without perturbing the original structure of hafnia