Structural characterization and 90° domain contribution to ferroelectricity of epitaxial Pb(Zr0.35,Ti0.65)O3 thin films

Abstract

Remanent polarizations (Pr) of 200-nm-thick epitaxial Pb(Zr0.35,Ti0.65)O3 (PZT) thin films deposited on (001), (110), and (111) SrTiO3 (STO) substrates coated with SrRuO3 (SRO) were compared to the domain configurations that were precisely and quantitatively characterized by high-resolution x-ray diffraction reciprocal space mapping (HRXRD-RSM). (001)/(100), (101)/(110), and (111) oriented domains were obtained for films grown on (001), (110), and (111) STO substrates coated with SRO, respectively. HRXRD-RSM showed that the films grown on (001) and (110) STO substrates mainly consisted of (001) and (101) domains, although they also included about 32% and 25% of (100) and (110) domain, respectively. Tilt growths in the domains were found except for the (001) domain. The tilt growths in the (100), (101), and (110) domains were attributed to the geometrically induced tilt by the 90° domain that had {101} domain walls. On the other hand, the tilt in the (111) domain was attributed to the misfit strain relaxation by introducing tilt growth in the domain but not due to the 90° domain. The Pr ratios of films having different domain configurations were well explained by the estimated Pr ratios from the volume fractions of the domains, based on the assumption that the 90° domain was not reoriented by the externally applied electrical field and did not contribute to the measured Pr values. This indicates that the 90° domain is strongly pinned in epitaxial 200-nm-thick PZT films and the 180° domain switching is the dominant contribution to the total remanent polarization.

Crystal structure, electrical properties, and mechanical response of (100)-/(001)-oriented epitaxial Pb(Mg1∕3Nb2∕3)O3–PbTiO3 films grown on (100)cSrRuO3‖(100)SrTiO3 substrates by metal-organic chemical vapor deposition

“…High-resolution XRD reciprocal space mapping 15 ͑HRXRD-RSM͒ was employed to analyze the crystal structure, including the film orientation, in-and out-of-plane lattice parameters, and the interaxial angle in detail. The composition of the film was measured with an x-ray fluorescence ͑XRF͒ spectrometer ͑PANalytical PW-2404͒, which was calibrated using sol-gelderived standard samples and cross-checked by Rutherford backscattering spectrometry ͑RBS͒.…”

Polarization states of polydomain epitaxialPb(Zr1−xTix)O3thin films and their dielectric properties

“…In particular, thin films of Pb(Zr 1-x Ti x )O 3 (PZT) have been fabricated in many laboratories worldwide, and even epitaxial PZT films were grown on many different substrates. [1][2][3][4][5][6][7][8][9][10][11][12][13] The experimental results demonstrated important distinctions between the properties of PZT in a thin-film and bulk forms, which triggered the first theoretical studies of PZT thin films. [14][15][16][17] Two approaches were employed in these studies, namely, the thermodynamic calculations and the phase-field simulations.…”

Orientation-dependent structural phase diagrams and dielectric properties ofPbZr1−xTixO3polydomai

“…1,2 Recent experimental work has demonstrated that the control of film orientation is one promising and effective approach to manipulate ferroelectric domain structure and properties. 3,4 In studies of thin-film materials, such as the model ferroelectrics PbZr 1−x Ti x O 3 and BiFeO 3 , it has been noted that the variation of film orientation could result in exotic crystal and domain structures and give rise to enhanced ferroelectric susceptibilities. [5][6][7][8] In particular, recent work on (111)-oriented, tetragonal PbZr 0.2 Ti 0.8 O 3 films highlighted how domain-wall contributions to dielectric susceptibilities and ferroelectric switching characteristics can be dramatically tuned with film orientations.…”