In:
Journal of Applied Physics, AIP Publishing, Vol. 110, No. 9 ( 2011-11-01)
Abstract:
Perovskite-type dense ceramics (La0.9Bi0.1)AlO3 (LBAO) have been prepared through a solid-state reaction route. LaAlO3 is indeed a paraelectric, whereas a significant ferroelectric relaxor behavior is obtained in LBAO. The variations of ferroelectric hysteresis loops versus the applied field or frequency indicate the nature of the ferroelectric domain switching. A broad dielectric anomaly coupled with the shift in dielectric maxima toward a higher temperature with increasing frequency has been observed in LBAO, and the indicator of degree of diffuseness γ is about 1.86. Moreover, the dielectric relaxation, which follows the Vogel–Fulcher relationship with TVF = 706.9 K, f0 = 1.85 × 109 Hz, and Ea = 0.09 eV, further supports spin-glass-like characteristics. Compared with LaAlO3, the abnormal contraction of crystal cell is observed in LBAO, which does not follow the normal Vegard’s law. This can be attributed to the covalent hybridization of the Bi3+ ions with the surrounding O2- ions. The large local displacements at the off-centered Bi position lead to the formation of polarized nanoclusters in the paraelectric matrix and the reorientation of these unstable polarized nanoclusters further results in ferroelectric relaxor behavior.
Type of Medium:
Online Resource
ISSN:
0021-8979
,
1089-7550
Language:
English
Publisher:
AIP Publishing
Publication Date:
2011
detail.hit.zdb_id:
220641-9
detail.hit.zdb_id:
3112-4
detail.hit.zdb_id:
1476463-5
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