Mixed cation phases in sputter deposited HfO{sub 2}-TiO{sub 2} nanolaminates

Journal Article · Mon Jul 14 00:00:00 EDT 2008 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.2957670· OSTI ID:21123968

Cisneros-Morales, M C; Aita, C R ^[1]

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1. Advanced Coatings Experimental Laboratory, College of Engineering and Applied Science, University of Wisconsin-Milwaukee, P.O. Box 784, Milwaukee, Wisconsin 53201 (United States)

Nanolaminate HfO{sub 2}-TiO{sub 2} films are grown by reactive sputter deposition on unheated fused SiO{sub 2}, sequentially annealed at 573 to 973 K, and studied by x-ray diffraction. A nanocrystalline structure of orthorhombic (o) HfTiO{sub 4} adjacent to an interface followed by monoclinic (m) Hf{sub 1-x}Ti{sub x}O{sub 2} is identified. m-Hf{sub 1-x}Ti{sub x}O{sub 2}, a metastable phase, is isomorphous with m-HfO{sub 2} and a high pressure phase, m-HfTiO{sub 4}. A Vegard's law analysis shows that the Ti atomic fraction in m-Hf{sub 1-x}Ti{sub x}O{sub 2} is much greater than Ti equilibrium solubility in m-HfO{sub 2}. A space group-subgroup argument proposes that m-Hf{sub 1-x}Ti{sub x}O{sub 2} arises from an o/m-HfTiO{sub 4} second order phase transition to accommodate the larger Hf atom.

• OSTI ID: 21123968
• Journal Information: Applied Physics Letters, Vol. 93, Issue 2; Other Information: DOI: 10.1063/1.2957670; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
CATIONS
DEPOSITION
DIELECTRIC MATERIALS
HAFNIUM OXIDES
MONOCLINIC LATTICES
NANOSTRUCTURES
ORTHORHOMBIC LATTICES
PHASE TRANSFORMATIONS
SILICON OXIDES
SOLUBILITY
SPACE GROUPS
SPUTTERING
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K
THIN FILMS
TITANIUM OXIDES
VEGARD LAW
X-RAY DIFFRACTION