Diseño y construcción de una fuente de tensión y corriente para sintetizar alúmina porosa nanoestructurada

Abstract

In this work is exposed the design, calibration and use of a voltage and current source for the synthesis of nanostructured porous Al2O3 (NPA) films. The operation of the source is regulated by an ATMEGA 328 microcontroller on an ARDUINO NANO [1] development board by pulse width modulation (PWM) with 8 bit precision, in a range of voltages from 0 - 40V and currents from 1- 5.6 mA, with uncertainties in the measurements of 5%. The instrument calibration curves are shown, where we evidenced the linearity of the response and a good agreement was achieved between the values commanded at the source with the direct measurements of the bench multimeter for the working ranges. This source was used for the synthesis of 4 APN samples under different conditions looking for a thickness in the order of 1300 nm. Reflectance spectra were obtained using an Ocean Optics USB-4000 spectrometer, and analyzed using a transfer matrix model that takes into account porosity, thickness, roughness, and trace concentrations of Fe2O3 and CuO.[2] We found that APN film thicknesses cannot be explained by anodizing times and currents alone. The role of porosity in the formation of APN films suggests that it is a subject of further attention.