Suppression of the Tetragonal Distortion in Thin Pb(Zr,Ti)O3 Films Grown on MgO(001)

1997 ◽  
Vol 493 ◽  
Author(s):  
H. C. Kang ◽  
D. Y. Noh ◽  
J. H. Je ◽  
H. K. Kim
Keyword(s):  
Phase Transformation ◽  
Transition Temperature ◽  
Thick Film ◽  
Tetragonal Phase ◽  
Lattice Mismatch ◽  
Tetragonal Distortion ◽  
Substrate Effect ◽  
X Ray ◽  
X Ray Scattering ◽  
Film Substrate

ABSTRACTThe paraelectric cubic to ferroelectric tetragonal phase transformation of thin Pb(Zr,Ti)O3/MgO(001) films was studied in synchrotron x-ray scattering experiments. As the thickness of the film decreases, the transition temperature and the amount of the tetragonal distortion were decreased continuously. The thinnest 250 Å thick film was purely composed of the c-type domains in the ferroelectric tetragonal phase. Based on this, we propose a model for the domain structure of the tetragonal PZT/MgO(001) film that is different from the ones suggested in literature. We attribute the suppression of the transition to the substrate effect that prefers the c-type domains near the interface, and reduces the tetragonal distortion to minimize the film-substrate lattice mismatch.

Crystallization of Amorphous Thin BST/MgO(001) Films Grown by R.F. Magnetron Sputtering

1997 ◽  
Vol 493 ◽  
Author(s):  
D. Y. Noh ◽  
H. H. Lee ◽  
J. H. Je ◽  
H. K. Kim
Keyword(s):  
Thick Film ◽  
Intermediate Phase ◽  
Perovskite Phase ◽  
Pyrochlore Phase ◽  
Interface Area ◽  
Crystalline Orientation ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Experiment ◽  
Film Substrate

ABSTRACTThe crystallization of amorphous BST thin films was studied in a synchrotron x-ray scattering experiment. At around 600°C, an intermediate phase, which was suspected to be a metastable pyrochlore phase, was formed. The x-ray reflectivity curves showed that the film-substrate interface became rough as the pyrochlore-like phase was formed. This suggests that the pyrochlore phase was nucleated near the interface area. Upon further annealing to higher temperatures, the film transformed to the crystalline perovskite phase. The crystallization was sensitive to the film thickness. In the thin 550Å thick film, the crystallization occurred at 750 °C with the <001> preferred orientation. On the other hand, the 5500Å thick film became crystalline even at 500°C with random crystalline orientation. The observed thickness dependence of the crystallization suggests that the crystalline perovskite phase was nucleated in the bulk of the film, rather than the near interface area.

Strain Analysis in Thin La1−xCaxMnO3 Films by Grazing Incidence X-ray Scattering

1999 ◽  
Vol 602 ◽  
Author(s):  
M. Petit ◽  
L. J. Martinez-Miranda ◽  
M. Rajeswari ◽  
A. Biswas ◽  
D. J. Kang ◽  
...  
Keyword(s):  
Film Thickness ◽  
Lattice Mismatch ◽  
Compressive Strain ◽  
Strain Analysis ◽  
Grazing Incidence ◽  
Relaxation Processes ◽  
Near Surface ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

AbstractWe have performed depth profile analyses of the lattice parameters in epitaxial thin films of La1−xCaxMno3 (LCMO), where x = 0.33 or 0.3, to understand the evolution of strain relaxation processes in these materials. The analyses were done using Grazing Incidence X-ray Scattering (GIXS) on films of different thicnesses on two different substrates, (100) oriented LaAlO3 (LAO), with a lattice mismatch of ∼2% and (110) oriented NGO, with a lattice mismatch of less than 0.1%. Films grown on LAO can exhibit up to three in-plane strained lattice constants, corresponding to a slight orthorhombic distortion of the crystal, as well as near-surface and columnar lattice relaxation. As a function of film thickness, a crossover from a strained film to a mixture of strained and relaxed regions in the film occurs in the range of 700 Å. The structural evolution at this thickness coincides with a change in the resistivity curve near the metalinsulator transition. The in-plane compressive strain has a range of 0.2 – 1.5%, depending on the film thickness for filsm in the range of 400 - 1500 A.

An X-ray scattering study on inverted Ge–Si huts grown at low temperatures

2004 ◽  
Vol 19 (4) ◽  
pp. 347-351
Author(s):  
J. Xu ◽  
X. S. Wu ◽  
B. Qian ◽  
J. F. Feng ◽  
S. S. Jiang ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Lattice Strain ◽  
Lattice Mismatch ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Large Lattice ◽  
Scattering Study

Ge–Si inverted huts, which formed at the Si∕Ge interface of Si∕Ge superlattice grown at low temperatures, have been measured by X-ray diffraction, grazing incidence X-ray specular and off-specular reflectivities, and transmission electron microscopy (TEM). The surface of the Si∕Ge superlattice is smooth, and there are no Ge–Si huts appearing on the surface. The roughness of the surfaces is less than 3 Å. Large lattice strain induced by lattice mismatch between Si and Ge is found to be relaxed because of the intermixing of Ge and Si at the Si∕Ge interface.

Principal Residual Strains as A function of Depth for Sputter Deposited Mo Thin Films

1994 ◽  
Vol 356 ◽  
Author(s):  
S. G. Malhotra ◽  
Z. U. Rek ◽  
L. J. Parfitt ◽  
S. M. Yalisove ◽  
J. C. Bilello
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grazing Incidence ◽  
X Ray ◽  
X Ray Scattering ◽  
Out Of Plane ◽  
Residual Strains ◽  
Sputter Deposited ◽  
Film Substrate ◽  
Principal Strains

AbstractTraditionally, the magnitude of the stress in a thin film is obtained by measuring the curvature of the film-substrate couple; however, these techniques all measure the average stress throughout the film thickness. On a microscopic level, the details of the strain distribution as a function of depth through the thickness of the film can have important consequences in governing film quality and ultimate morphology. A new method for determining the magnitude of principal strains (strain eigenvalues) as a function of x-ray penetration depth using grazing incidence x-ray scattering for a polycrystalline thin film will be described. Results are reported for two Mo metallizations ˜ 500 Å and ˜1000 Å thick sputtered onto Si {100} substrates. The magnitude of the principal strains at several penetration depths was accomplished by an analysis of the diffraction peak shifts of at least six independent {hkl} scattering vectors from the Mo thin films. An out-of-plane strain gradient was identified in both Mo films and the strain eigenvalues were found to be anisotropic in nature. This new methodology should work with a variety of thin films and hence would provide quantitative insight into the evolution of thin film microstructure.

X-ray study of the twinning and phase transformation of phosphocristobalite (AlPO4)

1977 ◽  
Vol 55 (7-8) ◽  
pp. 677-683 ◽  
Author(s):  
H. N. Ng ◽  
C. Calvo
Keyword(s):  
Phase Transformation ◽  
Transition Temperature ◽  
Short Range ◽  
X Ray ◽  
First Order ◽  
Β Phase ◽  
Α Phase ◽  
Short Range Correlations

Crystals of the cristobalite polymorph of AlPO4 (phosphocristobalite) up to 3 mm in breadth were grown from a V2O5 flux. In the α phase (C2221), the presence of twin domains prevents an accurate resolution of the structure as a function of temperature. The six twin components of this phase readily lead to a disordered β phase [Formula: see text] with short range correlations as suggested previously. The α–β transformation is first order with a substantial hysteresis in the transition temperature.

Grazing Incidence X-Ray Scattering Studies of Single Quantum Wells

1987 ◽  
Vol 31 ◽  
pp. 155-160
Author(s):  
S. Bates ◽  
P.D. Hatton ◽  
C.A. Lucas ◽  
T.W. Ryan ◽  
S.J. Miles ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Lattice Mismatch ◽  
Thick Layer ◽  
Grazing Incidence ◽  
Single Quantum ◽  
Individual Layer ◽  
Single Quantum Well ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

AbstractX-ray scattering techniques at grazing incidence have been used to characterize single quantum well hetero–structures. Double–and triple-axis diffractometry has been used to determine lattice mismatch and layer thickness of a 250Å thick layer of AlInAs grown by MBE on an InP substrate and capped by a 45Å GaAs layer. Reflectivity measurements in the triple – crystal mode permit accurate measurement of individual layer thicknesses, relative electron density and interface roughnesses on the Angstrom level.

Texture on Ground, Fractured, and Aged Y-TZP Surfaces

1986 ◽  
Vol 78 ◽  
Author(s):  
Franz Reidinger ◽  
Philip J. Whalen
Keyword(s):  
Phase Composition ◽  
Transition Temperature ◽  
Diffraction Analysis ◽  
Surface Treatment ◽  
Tetragonal Phase ◽  
Surface Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
History Of

ABSTRACTThe phase composition of Y-TZP surfaces has been shown to vary greatly depending on the thermo-mechanical history of the surface. The orientation of these different phases in the surface region is not always random. There is speculation that the alignment of the tetragonal phase before fracturing may play a part in increasing the toughness of these materials. This article deals with an X-ray diffraction analysis of various Y-TZP surfaces with special emphasis on the texture of the different phases. Surfaces which have been ground (and polished), fractured, and aged (200°C) have been examined. In all cases, the monoclinic component that was formed was strongly oriented. The tetragonal phase may or may not be oriented depending on surface treatment. Annealing above the monoclinic-tetragonal transition temperature had little effect on the tetragonal orientation in most cases. Samples fractured at 1000°C have no unusual orientation on the fracture faces.

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