8-12 July 2013
Thermodynamic stability of VO2 in contact with thin metal films
Presented by Ms. Nokwethemba Fortunate THABEZHE on 9 Jul 2013 from 17:40 to 18:40
Type: Poster Presentation
Track: Track A - Division for Condensed Matter Physics and Materials
Solid-state compound phase formation has been investigated between thin metal films (Co, Hf, Ni, Pd and Pt) and VO2 substrates using Rutherford backscattering spectrometry and X- ray diffraction techniques. The thin-film couples were annealed for time periods ranging from 45 min to 1 h between 400 oC and 900 oC. It was found that Hf reacts with VO2 whereas Co, Ni, Pd and Pt do not. Heats of reaction were calculated for all possible combinations of vanadium alloy and metal-oxide reaction products. Comparisons with experimental results obtained show in all cases that metal-VO2 reactions only take place where its calculated heats of reaction were negative. This study shows that the results obtained correlate well with the electronegativity of the metal, which offers a convenient empirical method of predicting whether a metal will react with VO2 or not. Only metals with a Miedema electronegativity parameter less than 4.9 Volts reacted with VO2.
Prof Muzi Ndwandwe firstname.lastname@example.org University of Zululand