Liquid Phase Epitaxy of Na1−yKyTa1−xNbxO3 for Pyroelectric Applications

1994 ◽  
Vol 361 ◽  
Author(s):  
Z. Sitar ◽  
R. Gutmann ◽  
H. Pierhöfer ◽  
P. Günter
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Ferroelectric Phase ◽  
Pyroelectric Coefficient ◽  
Partial Replacement ◽  
Sharp Change ◽  
Perfect Lattice ◽  
Lattice Matching ◽  
Ferroelectric Domain Structure ◽  
Pyroelectric Response

ABSTRACTThe epitaxial growth of para- and ferroelectric KTa1−xNbxO3 (KTN) thin films was achieved in an in-house built liquid phase epitaxy (LPE) apparatus. Films were grown from a KF/NaF/KTN solution on KTaO3 substrates. Growth rates of several μ/min were achieved at a growth temperature of 1200 K. Up to 150 μm thick, smooth KTN films with different compositions were grown and characterized. Almost perfect lattice matching was achieved by the addition of NaF to the KF flux. Partial replacement of K by Na did not result in a significant change of physical properties of KTN.The investigation of the dielectric properties revealed a sharp change of the dielectric constant at the ferroelectric phase transition. The ferroelectric domain structure was modified by poling at 1kV/cm. Pyroelectric studies yielded a pyroelectric coefficient of up to 5.2 mC/m2K while the frequency dependence of the pyroelectric response showed a maximum at 230 Hz.

Interfacial structures of Y123 and Nd123 films formed on MgO(001) substrates by liquid phase epitaxy

2004 ◽  
Vol 19 (9) ◽  
pp. 2674-2682 ◽  
Author(s):  
J.S. Matsuda ◽  
F. Oba ◽  
T. Murata ◽  
T. Yamamoto ◽  
Y. Ikuhara ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Molecular Orbital ◽  
Liquid Phase Epitaxy ◽  
Molecular Orbital Calculations ◽  
Lattice Matching ◽  
Transmission Electron ◽  
Interfacial Structures ◽  
Chemical Factors ◽  
Geometrical Matching ◽  
Interfacial Free Energies

Interfacial structures of c-axis-oriented YBa2Cu3O7–y (Y123) and Nd1+xBa2–xCu3O7–y (Nd123) films were investigated by high-resolution transmission electron microscopy (HRTEM) in conjunction with geometrical lattice matching and molecular orbital calculations. These films were formed on MgO(001) substrates by liquid-phase epitaxy. Despite the similarity in lattice constants between Y123 and Nd123, the in-plane orientation relationship (OR) to the substrates is different: [100]film//[100]substrate(I) for Y123 and [110]film//[100]substrate(II) for Nd123. From the results of HRTEM observations and image simulations, it was found that the Y123 and Nd123 films are terminated by BaO and CuO-chain layers at the interfaces, respectively. For both the Y123/MgO and Nd123/MgO systems, the OR(I) is assessed to be the most favorable in point of geometrical matching and the OR(II) is the second among the rotational misorientations on the [001]film and [001]MgO. The molecular orbital calculations reveal that the interface with the OR(II) and the CuO-chain layer termination is preferable in terms of covalent bonding for both the systems. Consequently, we suggest that the preferential interfacial structures are delicately determined by a balance of the geometrical and chemical factors at the interfaces, resulting in making the lowest interfacial free energies.

Preferential growth mechanism of REBa2Cu3Oy (RE = Y, Nd) crystal on MgO substrate by liquid phase epitaxy

2001 ◽  
Vol 16 (4) ◽  
pp. 979-989 ◽  
Author(s):  
Katsumi Nomura ◽  
Saburo Hoshi ◽  
Xin Yao ◽  
Kazuomi Kakimoto ◽  
Yuichi Nakamura ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Growth Mechanism ◽  
Liquid Phase Epitaxy ◽  
Coulomb Force ◽  
Preferential Growth ◽  
Lattice Matching ◽  
Interfacial Energies ◽  
Calculation Results ◽  
The Difference ◽  
Good Agreement

Growth of the REBa2Cu3Oy (REBCO, RE = Y, Nd) crystals on the MgO substrates by the liquid phase epitaxy (LPE) process was investigated to clarify the growth mechanism. The crystal orientation of in-plane alignment was improved during the LPE process due to the preferential dissolution and growth even from a polycrystalline seed film. The orientation of preferential growth depended on the kind of RE for the REBCO system. The phenomena could be explained by the coarsening model by introducing the difference in the interfacial energies, which were considered not only general lattice matching but the Coulomb force at the interface between the REBCO and the MgO crystals. The preferential growth model was developed, and the calculation results showed a good agreement with the experimental results.

The relationship between lattice matching and crosshatch in liquid phase epitaxy HgCdTe on CdZnTe substrates

1995 ◽  
Vol 24 (9) ◽  
pp. 1189-1199 ◽  
Author(s):  
S. P. Tobin ◽  
F. T. J. Smith ◽  
P. W. Norton ◽  
J. Wu ◽  
M. Dudley ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Lattice Matching ◽  
Cdznte Substrates ◽  
The Relationship

Multiple liquid phase epitaxy of In1−xGaxP1−zAszdouble‐heterojunction lasers: The problem of lattice matching

1977 ◽  
Vol 31 (1) ◽  
pp. 40-42 ◽  
Author(s):  
P. D. Wright ◽  
E. A. Rezek ◽  
N. Holonyak ◽  
G. E. Stillman ◽  
J. A. Rossi ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Lattice Matching

LATTICE MATCHING IN HgCdTe-CdZnTe HETEROJUNCTIONS

1985 ◽  
Vol 56 ◽  
Author(s):  
T. Maekawa ◽  
T. Saito ◽  
M. Yoshikawa ◽  
H. Takigawa
Keyword(s):  
Liquid Phase ◽  
Epitaxial Growth ◽  
Mole Fraction ◽  
Liquid Phase Epitaxy ◽  
Misfit Dislocations ◽  
Lattice Matching ◽  
Original Surface ◽  
Etch Pit

AbstractAn etch pit study has been made on misfit dislocations in (111) HgCdTe-CdZnTe heterojunctions grown by liquid phase epitaxy. It was shown that misfit dislocations were localized at the original surface of the substrate, because Zn diffused into the epilayer during epitaxial growth prevents movement of dislocations. For lattice matching between Hg0 7Cd0.3Te and Cd1−yZnyTe, the optimum ZnTe mole fraction of Cd1−yZnyTe was found to be 2.9%.

TEM study of very thin InGaAsP layers grown by liquid-phase epitaxy

1990 ◽  
Vol 48 (4) ◽  
pp. 672-673
Author(s):  
N.A. Bert ◽  
A.O. Kosogov
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Dark Field ◽  
Organic Chemical ◽  
Simple Liquid ◽  
Cross Sectional ◽  
Conventional Procedure ◽  
Double Heterostructures

The very thin (<100 Å) InGaAsP layers were grown not only by molecular beam epitaxy and metal-organic chemical vapor deposition but recently also by simple liquid phase epitaxy (LPE) technique. Characterization of their thickness, interfase abruptness and lattice defects is important and requires TEM methods to be used.The samples were InGaAsP/InGaP double heterostructures grown on (111)A GaAs substrate. The exact growth conditions are described in Ref.1. The salient points are that the quarternary layers were being grown at 750°C during a fast movement of substrate and a convection caused in the melt by that movement was eliminated. TEM cross-section specimens were prepared by means of conventional procedure. The studies were conducted in EM 420T and JEM 4000EX instruments.The (200) dark-field cross-sectional imaging is the most appropriate TEM technique to distinguish between individual layers in 111-v semiconductor heterostructures.

Silicon layers grown over SiO2 by liquid phase epitaxy: Electron Microscopical study

1990 ◽  
Vol 48 (4) ◽  
pp. 566-567
Author(s):  
F. Banhart ◽  
F.O. Phillipp ◽  
R. Bergmann ◽  
E. Czech ◽  
M. Konuma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
Plasma Etching ◽  
Liquid Phase Epitaxy ◽  
Three Dimensional ◽  
Microscopical Study ◽  
Sample Temperature ◽  
Structural Defects ◽  
Si Substrates ◽  
Etched Surface

Defect-free silicon layers grown on insulators (SOI) are an essential component for future three-dimensional integration of semiconductor devices. Liquid phase epitaxy (LPE) has proved to be a powerful technique to grow high quality SOI structures for devices and for basic physical research. Electron microscopy is indispensable for the development of the growth technique and reveals many interesting structural properties of these materials. Transmission and scanning electron microscopy can be applied to study growth mechanisms, structural defects, and the morphology of Si and SOI layers grown from metallic solutions of various compositions.The treatment of the Si substrates prior to the epitaxial growth described here is wet chemical etching and plasma etching with NF3 ions. At a sample temperature of 20°C the ion etched surface appeared rough (Fig. 1). Plasma etching at a sample temperature of −125°C, however, yields smooth and clean Si surfaces, and, in addition, high anisotropy (small side etching) and selectivity (low etch rate of SiO2) as shown in Fig. 2.

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