The finite size effect on the metal-insulator transition of MOCVD grown VO sub 2 films

Conference · Fri Nov 01 04:00:00 EST 1991

OSTI ID:5906979

Kim, Hyung Kook; Chiarello, R P; You, Hoydoo; Chang, M H.L.; Zhang, T J; Lam, D J

We studied the finite size effect on the metal-insulator phase transition and the accompanying tetragonal to monoclinic structural phase transition of VO{sub 2} films grown by MOCVD. X-ray diffraction measurements and electrical conductivity measurements were done as a function of temperature for VO{sub 2} films with out-of-plane particle size ranging from 60--310 {Angstrom}. Each Vo{sub 2} film was grown on a thin TiO{sub 2} buffer layer, which in turn was grown by MOCVD on a polished sapphire (112) substrate. The transition was found to be first order. As the out-of-plane particle size becomes larger, the transition temperature shifts and the transition width narrows. For the 60{Angstrom} film the transition was observed at {approximately}61{degrees}C with a transition width if {approximately}10{degrees}C, while for the 310{Angstrom} film the transition temperature was {approximately}59{degrees}C and the transition width {approximately} 2{degree}C. We also observed thermal hysteresis for each film, which became smaller with increasing particle size.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: DOE; KOSEF; USDOE, Washington, DC (United States); Korea Science and Engineering Foundation (Korea, Republic of)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5906979
• Report Number(s): ANL/CP-73695; CONF-911202--44; ON: DE92006969
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
COHERENT SCATTERING
DEPOSITION
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FILMS
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
SCATTERING
SIZE
SURFACE COATING
TEMPERATURE DEPENDENCE
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
VANADIUM OXIDES
X-RAY DIFFRACTION