Effect of thermal strain on the ferroelectric phase transition in polycrystalline Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} thin films studied by Raman spectroscopy

Journal Article · Mon Nov 01 00:00:00 EST 2004 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.1813625· OSTI ID:20634390

Tenne, D A; Soukiassian, A; Xi, X X; Taylor, T R; Hansen, P J; Speck, J S; York, R A ^[1]

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1. Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

We have applied Raman spectroscopy to study the influence of thermal strain on the vibrational properties of polycrystalline Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} films. The films were grown by rf magnetron sputtering on Pt/SiO{sub 2} surface using different host substrates: strontium titanate, sapphire, silicon, and vycor glass. These substrates provide a systematic change in the thermal strain while maintaining the same film microstructure. From the temperature dependence of the ferroelectric A{sub 1} soft phonon intensity, the ferroelectric phase transition temperature, T{sub C}, was determined. We found that T{sub C} decreases with increasing tensile stress in the films. This dependence is different from the theoretical predictions for epitaxial ferroelectric films. The reduction of the ferroelectric transition temperature with increasing biaxial tensile strain is attributed to the suppression of in-plane polarization due to the small lateral grain size in the films.

• OSTI ID: 20634390
• Journal Information: Applied Physics Letters, Vol. 85, Issue 18; Other Information: DOI: 10.1063/1.1813625; (c) 2004 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
BARIUM COMPOUNDS
CRYSTAL STRUCTURE
EPITAXY
FERROELECTRIC MATERIALS
GRAIN SIZE
PHASE TRANSFORMATIONS
PLATINUM
POLARIZATION
POLYCRYSTALS
RAMAN SPECTROSCOPY
SAPPHIRE
SILICON
SILICON OXIDES
SPUTTERING
STRONTIUM TITANATES
TEMPERATURE DEPENDENCE
THERMAL STRESSES
THIN FILMS
TRANSITION TEMPERATURE
VYCOR