Dielectric and ferroelectric properties of lanthanum doped SrBi{sub 4}Ti{sub 4}O{sub 15} ferroelectric ceramics
- Vardhaman College of Engineering, Shamshabad (India)
- National Centre for Compositional Characterization of Materials, Bhabha Atomic Research Centre, Hyderabad (India)
- Department of Physics, Jawaharlal Nehru Technological University, College of Engineering, Hyderabad (India)
Bismuth layer structure ferroelectrics (BLSFs) have attracted intensive investigation for the potential use in non volatile ferroelectric random access memory (FeRAM) and piezoelectric devices suitable at high temperature. Bismuth layered structured compounds with general formula of (Bi{sub 2}O{sub 2}){sup 2+} (A{sub m-1}B{sub m}O{sub 3m+1}){sup 2-} are firstly found by Aurivillius. The structure of these compounds can be described as pseudo-perovskite (A{sub m-1}B{sub m}O{sub 3m+1}){sup 2-} slabs separated by (Bi{sub 2}O{sub 2}){sup 2+} layers along the crystallographic c-axis. The 12-coordinated A site can be occupied by such cations as La{sup 3+}, Bi{sup 3+}, Ba{sup 2+}, Sr{sup 2+}, Pb{sup 2+}, Ca{sup 2+}, Na{sup +}, etc. While the octahedral-coordinated B site can be occupied by W{sup 6+}, Nb{sup 5+}, Ta{sup 5+}, Ti{sup 4+} etc. Lanthanum substituted BiT (Bi{sub 4}Ti{sub 4}O{sub 12}) known as BLT has been extensively investigated. With this substitution, BLT shows relatively large P{sub r}, low synthesis temperature and good fatigue endurance which makes it a potential candidate for FeRAM application. So, lanthanum doping is an effective way to improve the ferroelectric and fatigue properties of Bi{sub 4}Ti{sub 4}O{sub 12}. Lanthanum doped Bismuth layer structure ferroelectrics (BLSFs) ceramics SrBi{sub 4-x}La{sub x}Ti{sub 4}O{sub 15} (x=0, 0.025, 0.050, 0.075, 0.1) were prepared by solid state reaction method. X-ray diffraction pattern showed that single phase was formed when x=0-0.1. Morphological studies were carried out by SEM analysis. It was found that crystal lattice constant, dielectric and electrical properties of SBT ferroelectrics varied appreciably with amount of doping. Dielectric measurements in the frequency range 100Hz-1MHz were made using an impedance analyzer (Wayne Kerr 6500P) and the measurements were carried out from RT to 600 deg C. The ferroelectric hysteresis loop was traced at room temperature by a standard P-E loop tracer based on sawyer-tower circuit. The values of 2P{sub r} and E{sub c} for pure and lanthanum doped SBT are given. The above results indicate that La{sup 3+} modification is an effective way to improve the ferro electrical properties of SrBi{sub 4}Ti{sub 4}O{sub 15}. The transition temperature (T{sub c}) and dielectric constant for SrBi{sub 4}Ti{sub 4}O{sub 15} are given. It is observed that with the increasing of lanthanum content remnant polarization increases and coercive field decreases. It is believed that these materials are potentially attractive candidates for FeRAM industry.
- Research Organization:
- IEEE Electron Devices Society - Vacuum Electronics Committee, IEEE ED-SSC Joint Chapter, Bangalore (India)
- OSTI ID:
- 22078280
- Resource Relation:
- Conference: IVEC-2011: 12. IEEE international vacuum electronics conference, Bangalore (India), 21-24 Feb 2011; Other Information: Country of input: India; 4 refs., 2 tabs.; This record replaces 44037464; Related Information: In: Proceedings of the 2011 IEEE international vacuum electronics conference: book of abstracts| 564 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Raman scattering investigations on lanthanum-doped Bi{sub 4}Ti{sub 3}O{sub 12}-SrBi{sub 4}Ti{sub 4}O{sub 15} intergrowth ferroelectrics
Upconversion luminescence, ferroelectrics and piezoelectrics of Er Doped SrBi{sub 4}Ti{sub 4}O{sub 15}