Spectroscopic Determination of Phase in Tetragonally Strained Ba0.5Sr0.5TiO3 Films at Room Temperature
Sputter-deposited Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} thin films on MgO(001) substrates with either in-plane (c<a) or out-of-plane (c>a) tetragonal lattice structure distortions were characterized by polarization-dependent Ti K-edge x-ray absorption fine-structure (XAFS) spectroscopy and microwave dielectric measurements. Anisotropy between the in-plane and out-of-plane directions in the films as determined by XAFS provided evidence of spontaneous polarization, and the anisotropy varied with the type of structural distortion. These results explain microwave measurements in which the dielectric properties were significantly affected by lattice distortions and exhibited hysteresis in the in-plane dielectric constant with dc bias at room temperature, suggesting the presence of permanent dipoles.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 930524
- Report Number(s):
- BNL-80549-2008-JA; APPLAB; TRN: US200904%%767
- Journal Information:
- Applied Physics Letters, Vol. 91; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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