Microstructure of PbTiO[sub 3] thin films deposited on (001) MgO by MOCVD

Journal Article · Fri Jan 01 04:00:00 EST 1993 · Journal of Materials Research; (United States)

DOI:https://doi.org/10.1557/JMR.1993.0145· OSTI ID:6926371

Gao, Y; Bai, G; Merkle, K L; Shi, Y; Chang, H L.M.; Shen, Z; Lam, D J ^[1]

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1. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

PbTiO[sub 3] thin films deposited on (001)MgO by the MOCVD technique have been characterized by x-ray diffraction and transmission electron microscopy (TEM). The PbTiO[sub 3] films grown at temperatures below [ital T][sub [ital C]] ([similar to]500 [degree]C) are c-axis oriented polycrystals, while the PbTiO[sub 3] films grown at temperatures above [ital T][sub [ital C]] are single crystals with a bi-layer structure at room temperature. The top layers of the films near the free surface are [ital c]-axis oriented with the orientation relationship of (001)[100]PbTiO[sub 3][parallel](001)[100]MgO. The bottom layers of the films near the substrate are [ital a]-axis oriented with the orientation relationship of (100)[00[bar 1]]PbTiO[sub 3][parallel](001)[100]MgO. The formation of the bi-layer microstructure of the PbTiO[sub 3] films will be discussed in terms of the effect of the cooling rate and the substrate on the phase transition of PbTiO[sub 3] from the cubic to the tetragonal phase. When the PbTiO[sub 3] films were grown with large excess of the Pb precursor vapor in the vapor mixture, PbO and PbTiO[sub 3] coexisted in the films. Both PbO and PbTiO[sub 3] were grown epitaxially on (001)MgO. The epitaxial orientation relationships were found to be (100)[001]PbO[parallel](001)[100]MgO and (001)[100]PbTiO[sub 3][parallel](001)[100]MgO. The 90[degree] domains were observed in the PbTiO[sub 3] films deposited at temperatures above [ital T][sub [ital C]]. The domain walls are the [l brace]101[r brace] and [l brace]011[r brace] twin boundaries, which were formed during the phase transition from the cubic to the tetragonal phase.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6926371
• Journal Information: Journal of Materials Research; (United States), Journal Name: Journal of Materials Research; (United States) Vol. 8:1; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
COHERENT SCATTERING
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
CRYSTALS
DEPOSITION
DIFFRACTION
ELECTRON MICROSCOPY
FILMS
LEAD COMPOUNDS
MICROSCOPY
MICROSTRUCTURE
MONOCRYSTALS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
POLYCRYSTALS
SCATTERING
SURFACE COATING
THIN FILMS
TITANATES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION