X-ray photoelectron spectroscopy characterization of fluorite and perovskite phases in Sr{sub 1-x}Bi{sub 2+y}Ta{sub 2}O{sub 9-z} films

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3499252· OSTI ID:21476559

Akazawa, Housei ^[1]; Ando, Hiroshi ^[2]

---

1. NTT Microsystem Integration Laboratories, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198 (Japan)
2. NTT Advanced Technology, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198 (Japan)

High-resolution x-ray photoelectron spectroscopy of strontium bismuth tantalate films revealed distinct chemical states of constituent atoms in fluorite and perovskite crystals. Reflecting the number of nearest-neighbor oxygen atoms coordinated with Bi{sup 3+} ions, the Bi 4f peak could be deconvoluted into Bi{sub 2}O{sub 3} (sixfold coordination), Bi{sub 2}O{sub 2} (fourfold coordination), and (Bi{sub 2}O{sub 2}){sup 2+} (intermediate between sixfold and fourfold coordination) components. We found that amorphous and fluorite phases could be expressed as a mixture of Bi{sub 2}O{sub 3} and Bi{sub 2}O{sub 2}, whereas the (Bi{sub 2}O{sub 2}){sup 2+} component representing the bismuth oxide layer, being adjacent to the (SrTa{sub 2}O{sub 7}){sup 2-} block, predominated in the perovskite phase. Similarly, the Sr 3d peak could be deconvoluted into the components of Sr oxide (SrO) and Sr in (SrTa{sub 2}O{sub 7}){sup 2-}. The volume fraction of the (SrTa{sub 2}O{sub 7}){sup 2-} component increased at higher annealing temperatures. The Ta 4d peaks, in contrast, located at the same binding energy for all samples, indicated that an energetically stable TaO{sub 6} octahedron unit is preferentially created. The binding energies of the O 1s state corresponding to O-Bi, O-Ta, and O-Sr bonds were identified at 531, 530, and 528.9 eV, respectively.

• OSTI ID: 21476559
• Journal Information: Journal of Applied Physics, Vol. 108, Issue 8; Other Information: DOI: 10.1063/1.3499252; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AMORPHOUS STATE
ANNEALING
BINDING ENERGY
BISMUTH IONS
BISMUTH OXIDES
CHEMICAL BONDS
CONCENTRATION RATIO
CRYSTALS
CUBIC LATTICES
EV RANGE
FERROELECTRIC MATERIALS
LAYERS
S STATES
STRONTIUM OXIDES
TANTALATES
TEMPERATURE DEPENDENCE
THIN FILMS
X-RAY PHOTOELECTRON SPECTROSCOPY
ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
CHALCOGENIDES
CHARGED PARTICLES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIELECTRIC MATERIALS
DIMENSIONLESS NUMBERS
ELECTRON SPECTROSCOPY
ENERGY
ENERGY LEVELS
ENERGY RANGE
FILMS
HEAT TREATMENTS
IONS
MATERIALS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
REFRACTORY METAL COMPOUNDS
SPECTROSCOPY
STRONTIUM COMPOUNDS
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS