Defect structure and phase transitions in epitaxial metastable cubic Ti sub 0. 5 Al sub 0. 5 N alloys grown on MgO(001) by ultra-high-vacuum magnetron sputter deposition

Journal Article · Wed May 01 04:00:00 EDT 1991 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.348849· OSTI ID:5491760

Adibi, F; Petrov, I; Hultman, L; Wahlstroem, U; Shimizu, T; McIntyre, D; Greene, J E ^[1]; Sundgren, J ^[2]

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1. Department of Materials Science, the Coordinated Science Laboratory, and the Materials Research Laboratory, University of Illinois, 1101 West Springfield Avenue, Urbana, Illinois 61801 (USA)
2. Thin Film Group, Physics Department, Linkoeping University, S-581 83 Linkoeping, (Sweden)

Ti{sub 0.5}Al{sub 0.5}N alloy films, typically 1.5 {mu}m thick, were grown on MgO(001) at temperatures {ital T}{sub {ital s}} between 400 and 850 {degree}C by ultra-high-vacuum reactive magnetron sputtering in pure N{sub 2}. Films grown at {ital T}{sub {ital s}} between {congruent}480 and 560 {degree}C were single crystals in which the lattice misfit strain was partially relieved by glide of {l angle}001{r angle} misfit dislocations, with Burgers vector ={ital a}{sub 0}/2{l angle}011{r angle}, on {l brace}01{bar 1}{r brace} planes. Cross-sectional transmission electron microscopy investigation showed no evidence of residual extended defects in the films until thicknesses of {congruent}150 nm at which point threading dislocations, oriented along the (001) growth direction, were observed. Surface-initiated spinodal decomposition, resulting in the formation of compositionally modulated NaCl-structure platelets along (001) with width {congruent}1 nm, occurred over a narrow growth temperature range between 540 and 560 {degree}C as a precursor to bulk phase separation of wurtzite-structure AlN at {ital T}{sub {ital s}}{ge}560 {degree}C. The alloy was continuously depleted of AlN at higher growth temperatures until the equilibrium two-phase structure, cubic TiN and wurtzite AlN, was obtained at {ital T}{sub {ital s}}{ge}750 {degree}C.

• OSTI ID: 5491760
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 69:9; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM NITRIDES
CHALCOGENIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
NITRIDES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PNICTIDES
SORPTIVE PROPERTIES
SPUTTERING
SURFACE PROPERTIES
TITANIUM ALLOYS
TITANIUM COMPOUNDS
TITANIUM NITRIDES
TRANSITION ELEMENT COMPOUNDS