Reflectance and colorimetric analysis of copper (I) oxide (Cu2O) surface layer

Date

3-2001

Degree

Bachelor of Science in Applied Physics

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Emmanuel A Florido

Abstract

A reflectance spectrophotometer was designed and implemented to acquire the reflectance spectra of commercially-sold copper sheets which are thermally oxidized. The system is capable of measuring the reflectance at specular reflection 45°/0 geometry. The entire system was interfaced to a computer for streamlined data gathering and storage. The reflectance spectra from the thermally oxidized copper sheets were measured by means of synchronous detection through an oscilloscope and lock-in amplifier. The copper oxide was grown on the sheets using a stove at constant temperature but at different time intervals. The oxide exhibited color changes as it thickened. Evidence of weight increase and oxide thickness was verified using an analytical balance and a Scanning Electron Microscope (SEM) respectively. Both weight increase and oxide thickness exhibited logarithmic trends. Each treated sample was measured for its reflectance relative to magnesium oxide as reference standard. The reflectance values were used to calculate for the tristimulus values X, Y, and Z. These tristimulus values were used to obtain the chromaticity coordinates which was used to locate the color of the sample in the 1931 and 1976 CIE Chromaticity diagram. Using the same values, the dominant wavelength was also computed using a worksheet provided by Dr. Yoshi Ohno of the National Institute of Standards and Technology. The study showed an increase in thickness tends to improve the reflectance and green range of the spectrum but when the thickness reaches 91.89 1.1m, both the reflectance and green range drops. Using reflectance spectra examination and color recognition, it would be possible to estimate the thickness of the oxide on a copper sheet.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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