Optical properties and stoichiometry of reactively evaporated VO/sub 2/ thin films

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5830678

Nyberg, G A

Many of the physical properties of VO/sub 2/ are highly dependent on sample preparation. Although thin-film deposition technology has improved markedly in recent years, very few qualitative changes in the deposition of VO/sub 2/ thin films have been reported during this time. This thesis reports the first successful reactive evaporation of high-quality VO/sub 2/ films. Oxygen pressure and flow were controlled to about 1%. The film temperature was controlled to +/-4/sup 0/C. The greatest source of process instability was the deposition rate. For typical deposition parameters of 520/sup 0/C, 11 x 10/sup -4/ torr oxygen pressure, and a 30A/min deposition rate, the reactively evaporated VO/sub 2/ thin films were qualitatively similar to the films deposited by other means as reported in the literature. But for deposition parameters of 590/sup 0/C, 12-2 x 10/sup -4/ torr of oxygen, and 30A/min, unique optical properties were discovered; the film (transmission) color changed from blue to red at the semiconductor to metal transition of 65/sup 0/C. The expected behavior is a brass color in both phases. All films with the blue/red colors had positive temperature coefficients of resistivity. Increased grain sizes, increased resistivity ratios, and decreased adhesion accompanied the unique optical behavior.

• Research Organization: Cornell Univ., Ithaca, NY (USA)
• OSTI ID: 5830678
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
VANADIUM OXIDES
OPTICAL PROPERTIES
STOICHIOMETRY
DEPOSITION
EVAPORATION
HIGH TEMPERATURE
THIN FILMS
CHALCOGENIDES
FILMS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties