In:
Applied Physics Letters, AIP Publishing, Vol. 85, No. 16 ( 2004-10-18), p. 3516-3518
Abstract:
Epitaxial Pb(Zr,Ti)O3 (PZT) films 50 and 250nm thick with the Zr∕(Zr+Ti) ratio from 0.13 to 0.65 were grown on (100)cSrRuO3∕∕(100)SrTiO3 substrates at 540°C by pulsed-metalorganic chemical vapor deposition. The crystal orientation, lattice parameter, axial angle, and relative volume fraction of constituent domains were determined by high-resolution x-ray diffraction reciprocal space mapping. We grew (100) and∕or (001)-oriented epitaxial PZT films for the whole Zr∕(Zr+Ti) ratio. A tetragonal single phase was obtained for the Zr∕(Zr+Ti) ratio ranging from 0.13 to 0.54 and 0.19 to 0.45 with the 50 and 250nm thick films, respectively, while mixed phases of a tetragonal and rhombohedral from 0.45 to 0.60 for the 250nm thick films was obtained. For the films consisting of a tetragonal single phase, lattice parameters of a- and c-axes and their ratio (c∕a) were almost the same as the reported data for the PZT powder, suggesting a small amount of residual strain in them. In addition, perfectly polar-axis (c-axis)-oriented tetragonal films were obtained for the 50nm thick films, while an ∼70% c-axis-orientation for the 250nm thick ones was obtained. Polarization–electric-field hysteresis loops with a good square shape were observed for all films. Also, spontaneous polarization (Ps) values that were directly measured for the 50nm thick films and estimated for the 250nm thick films taking into account the volume fraction of the polar-axis-orientated domain were closely in line with the Zr∕(Zr+Ti) ratio, and they decreased as the ratio increased. The square of the estimated Ps was found to be proportional to the crystal distortion, c∕a−1. These results are essential not only for understanding the origin of the large Ps of PZT but for the property design of the ferroelectric devices using PZT.
Type of Medium:
Online Resource
ISSN:
0003-6951
,
1077-3118
Language:
English
Publisher:
AIP Publishing
Publication Date:
2004
detail.hit.zdb_id:
211245-0
detail.hit.zdb_id:
1469436-0
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