Mechanism of the ''low-temperature'' oxidation of molybdenum disilicide layers on molybdenum

Journal Article · Wed May 01 04:00:00 EDT 1985 · Dokl. Phys. Chem. (Engl. Transl.); (United States)

OSTI ID:6998575

Bulbenkov, N A; Krasovskii, A I; Tsirlin, M S

Previous studies on the oxidation of molybdenum disilicide layers on molybdenum, produced by diffusion silicization of the metal, lead the authors to conclude that the structural correspondence between the starting material and the reaction product (MoSi/sub 2/ and alpha-quartz, respectively) determines the mechanism of the low-temperature oxidation, and makes the limit of alpha-quartz stability - 1450 C - the upper limit for the operation of this mechanism. The authors consider oxidation kinetics in the low temperature and high temperature regions and find that molybdenum is able to diffuse outward, thus preventing the formation of a MO/sub 5/Si/sub 3/ layer at the SiO/sub 2/-MoSi/sub 2/ interface. As the SiO/sub 2/ film gets thicker, appreciable formation of the Mo/sub 5/Si/sub 3/ layer begins; this is the stage at which the sample gains weight. It is shown that in the high-temperature process all the disilicide silicon is oxidized by a reaction that makes the silicon dioxide volume and mass twice as large as in the lowtemperature process, and prevents MoO/sub 3/ separation in the early stages.

• Research Organization: Institute of Physical Chemistry, Acad. of Sci., Moscow
• OSTI ID: 6998575
• Journal Information: Dokl. Phys. Chem. (Engl. Transl.); (United States), Journal Name: Dokl. Phys. Chem. (Engl. Transl.); (United States) Vol. 279:1-3; ISSN DKPCA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CRYSTAL GROWTH
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
DEPOSITION
DIFFUSION
DIFFUSION COATING
ELEMENTS
FILMS
KINETICS
METALS
MINERALS
MOLYBDENUM
MOLYBDENUM COMPOUNDS
MOLYBDENUM SILICIDES
OXIDATION
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
QUARTZ
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
SILICIDES
SILICON COMPOUNDS
SILICON OXIDES
SURFACE COATING
TEMPERATURE EFFECTS
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS