Subcategory: Materials Science
Tanviben Patel - Elizabeth City State University
Co-Author(s): Ama Agyapong and Adetayo Adedeji, Elizabeth City State University, Elizabeth City, NC
According to previous research, vanadium dioxide (VO2) is a spectrally selective thermochromic material that endures reversible structural changes at temperature of 68 °C. The objective of this research is to observe and enhance the thermochromic properties of VO2 by adding small amount of niobium (Nb) on the samples. Literature shows that impurities added to VO2 can drive down the transition temperatures. The samples were coated by DC magnetron sputtering of vanadium metal and RF co-sputtering of Nb metal. Samples deposited on quartz and diamond substrates were annealed at 500 °C in pure oxygen and nitrogen gas for 4 hours at the pressure of 800 mtorr to obtain VO2 with added impurity. The optical and electrical data on the samples were acquired as a function of temperatures, from room temperature to about 90 °C and back to room temperature. Surface morphology of the samples has been obtained using SEM before and after oxidization. The images of surface morphology indicate the uniformity of the samples. Energy Dispersive Spectroscopy (EDS) gave the atomic composition of the oxidized coatings. The deposition and characterization steps were repeated to ensure reproducibility. The future work includes variation in the thickness of the coating.
Funder Acknowledgement(s): National Science Foundation
Faculty Advisor: Adetayo Adedeji,