Hetero-Epitaxial Structures of Litao3 Thin Films

1995 ◽  
Vol 401 ◽  
Author(s):  
L.-S. Hung
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Optical Waveguide ◽  
Conducting Layer ◽  
Epitaxial Thin Films ◽  
Surface Polarity ◽  
Lattice Matching ◽  
Ion Channeling ◽  
Crystal Imperfection ◽  
Good Lattice

AbstractWe have grown epitaxial thin films of LiTaO3 on various substrates. LiTaO3 grows epitaxially on (111) GaAs and forms a waveguide with its underlying buffer layer of MgO, providing a desirable structure for monolithic integration. LiTaO3 grows on LiNbO3 with a buffer layer of magnesium niobate or magnesium tantalate to form an optical waveguide structure having good lattice matching and pronounced differences in refractive index. This heterostructure has the potential for reducing crystal imperfection of waveguides and improving optical confinement. We also describe a multilayer structure using an epitaxial conducting layer as a bottom electrode to grow a nonlinear optical waveguide on LiNbO3 for waveguide switching and modulation. Both light-absorbing metals and transparent metallic oxides are employed. Ion channeling and x-ray diffraction reveal high crystalline quality of the hetero-epitaxial structures. The influence of surface polarity, thermal expansion, and lattice matching on waveguiding LiTaO3 thin films is addressed.

Interfacial Strain Reliefs in Epitaxial YBa2Cu3O7–δ Thin Films Grown on SrTiO3 Buffered MGO Substrates

1997 ◽  
Vol 505 ◽  
Author(s):  
Xingtian Cui ◽  
Q. Y Chen ◽  
Yongxiang Guo ◽  
W. K. Chu
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Rutherford Backscattering Spectrometry ◽  
Epitaxial Thin Films ◽  
Cross Sectional ◽  
Ybco Films ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Edge Dislocations

ABSTRACTHigh quality YBa2Cu3O7–δ, (YBCO) epitaxial thin films grown on MgO substrate with a strainrelieved SrTiO3 (STO) buffer layer have been investigated by Rutherford backscattering spectrometry (RBS), ion channeling and high resolution cross sectional transmission electron microscopy (XTEM). The in-situ growth of STO buffer layer along with the YBCO films was carried out by pulsed laser ablation. In this work, minimum yield of channeling measurements have shown that a very thin STO buffer layer is sufficient to grow highly crystalline YBCO thin films on MgO substrates. TEM studies showed that the STO layers were strain-relieved by an array of periodic edge dislocations. The YBCO films on STO buffer, as in those grown directly on an STO substrate, evolved from a strained layer to a largely dislocation free area.

Texture Studies on Borocarbide Thin Films

2005 ◽  
Vol 495-497 ◽  
pp. 1425-1430 ◽  
Author(s):  
K. Subba Rao ◽  
R. Tamm ◽  
S.C. Wimbush ◽  
G.H. Cao ◽  
C.G. Oertel ◽  
...  
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Pulsed Laser ◽  
The Other ◽  
Laser Deposition ◽  
Epitaxial Thin Films ◽  
Secondary Phases ◽  
Superconducting Properties ◽  
Phase Purity ◽  
Y2o3 Buffer Layer

Epitaxial thin films of the superconducting borocarbide compound YNi2B2C were grown on single crystal MgO (100) substrates without and with Y2O3 buffer layer using pulsed laser deposition (PLD). In both cases YNi2B2C grows with [001] normal to the substrate. However, the in-plane texture depends on the starting condition. For samples without buffer layer, oxygen from the substrate diffuses into the film and forms an Y2O3 reaction layer at the interface. As a consequence, a deficiency of Y is generated giving rise to the formation of secondary phases. On the other hand, using an artificial Y2O3 buffer layer secondary phases are suppressed. The texture of the Y2O3 layers determines the texture of the YNi2B2C film. The superconducting properties of the borocarbide films are discussed with respect to texture and phase purity.

Morphology of Epitaxially Grown BaRuO3 and CaRuO3 Thin Films by Laser Ablation

2007 ◽  
Vol 352 ◽  
pp. 315-318 ◽  
Author(s):  
Akihiko Ito ◽  
Hiroshi Masumoto ◽  
Takashi Goto
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Conductivity ◽  
Laser Ablation ◽  
Flat Surface ◽  
High Electrical Conductivity ◽  
Island Growth ◽  
Lattice Matching ◽  
Metallic Conduction ◽  
Good Lattice

Epitaxial BaRuO3 (BRO) and CaRuO3 (CRO) thin films were prepared on (001), (110) and (111) SrTiO3 (STO) single-crystal substrates by laser ablation, and their microstructures and anisotropy of electrical conductivity were investigated. The (205) (104), (110) and (009) oriented BRO thin films, and (001), (110) and (110) oriented CRO thin films were grown epitaxially on (001), (110) and (111) STO substrates with in-plain orientation, respectively. The (009) BRO thin film and (001) CRO thin film has a flat surface result from a good lattice matching to STO substrates. The (205) (104) BRO thin film and (111) CRO thin film exhibited orthogonal- and hexagonal-shaped texture, respectively. The (110) BRO thin film and (110) CRO thin film showed an island growth due to (110) surface feature of cubic perovskite structure. Epitaxial BRO and CRO thin films have a high electrical conductivity with a metallic conduction, the (111) CRO thin films exhibited the highest conductivity of 1.4×105 S·m-1.

Fabrication of ScAlMgO4 epitaxial thin films using ScGaO3(ZnO)m buffer layers and its application to lattice-matched buffer layer for ZnO epitaxial growth

2008 ◽  
Vol 516 (17) ◽  
pp. 5842-5846 ◽  
Author(s):  
Takayoshi Katase ◽  
Kenji Nomura ◽  
Hiromichi Ohta ◽  
Hiroshi Yanagi ◽  
Toshio Kamiya ◽  
...  
Keyword(s):  
Thin Films ◽  
Epitaxial Growth ◽  
Buffer Layer ◽  
Buffer Layers ◽  
Epitaxial Thin Films ◽  
Lattice Matched

Lattice distortion effects on electrical switching in epitaxial thin film NdNiO3

1995 ◽  
Vol 10 (12) ◽  
pp. 2992-2995 ◽  
Author(s):  
J.F. DeNatale ◽  
P.H. Kobrin
Keyword(s):  
Thin Films ◽  
Lattice Distortion ◽  
Polycrystalline Material ◽  
Epitaxial Thin Films ◽  
Epitaxial Thin Film ◽  
Electrical Switching ◽  
Lattice Matching ◽  
Lattice Strains ◽  
Polycrystalline Ceramics ◽  
Matching Constraints

Crystalline thin films of NdNiO3 have been epitaxially grown on the (100) face of single-crystal LaAlO3 substrates. These films exhibit the characteristic reversible change in electrical conductivity with temperature previously observed in bulk polycrystalline material. The temperature of the electrical transition in the epitaxial thin films was lower than reported for the bulk polycrystalline ceramics. This effect is attributed to lattice strains associated with the film processing and interfacial lattice matching constraints.

Hydrothermally grown ZnO buffer layer for the growth of highly (4wt%) Ga-doped ZnO epitaxial thin films on MgAl2O4 (111) substrates

2011 ◽  
Vol 322 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Seung Wook Shin ◽  
Ye Bin Kwon ◽  
A.V. Moholkar ◽  
Gi-Seok Heo ◽  
In Ok Jung ◽  
...  
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Epitaxial Thin Films ◽  
Doped Zno ◽  
Zno Buffer Layer

Fabrication of SrRuO3 Epitaxial Thin Films on YBa2Cu3Ox / CeO2 / YSZ - Buffered Si Substrates by Pulsed Laser Deposition

2003 ◽  
Vol 786 ◽  
Author(s):  
Takamitsu Higuchi ◽  
Koichi Morozumi ◽  
Setsuya Iwashita ◽  
Masaya Ishida ◽  
Tatsuya Shimoda
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Buffer Layer ◽  
Process Condition ◽  
Pulsed Laser ◽  
High Energy ◽  
Laser Deposition ◽  
Epitaxial Thin Films ◽  
Rocking Curve ◽  
Si Substrates

ABSTRACTPseudocubic SrRuO3 (100) epitaxial thin films were fabricated on Si (100) with a YBa2Cu3Ox / CeO2 / YSZ (yttria-stabilized-zirconia) triple buffer layer ∼ 14 nm thick by pulsed laser deposition (PLD). Reflection high-energy electron diffraction (RHEED) and X-ray diffraction (XRD) revealed that the first buffer layer of YSZ (100) was epitaxially grown on naturally oxidized Si (100) substrates with the process condition of PB (base pressure) = 1×10-Torr, PO2 (oxygen partial pressure) = 5×10- Torr, and Ts (substrate temperature) = 700 °C. Higher deposition rate of YSZ in the range of 0 ∼ 0.6 nm/min brought about better crystallinity with a smaller value of a full-width at half maximum (FWHM) in the YSZ (200) rocking curve. Subsequent deposition of CeO2, YBa2Cu3Ox, and SrRuO3 resulted in an SrRuO3 (100) epitaxial thin film exhibiting good crystallinity with FWHM = 1.7° in the SrRuO3 (200) rocking curve.

Room-temperature growth of ultrasmooth AlN epitaxial thin films on sapphire with NiO buffer layer

2004 ◽  
Vol 19 (9) ◽  
pp. 2725-2729 ◽  
Author(s):  
Atsushi Sasaki ◽  
Jin Liu ◽  
Wakana Hara ◽  
Shusaku Akiba ◽  
Keisuke Saito ◽  
...  
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Room Temperature ◽  
Epitaxial Thin Films ◽  
X Ray Diffraction ◽  
Epitaxial Relationship ◽  
Heteroepitaxial Structure ◽  
Temperature Growth ◽  
X Ray ◽  
Relationship Of

Room-temperature epitaxy of AlN thin films on sapphire (0001) substrates was achieved by pulsed laser deposition using an epitaxial NiO ultrathin buffer layer (approximately 6 nm thick). Four-circle x-ray diffraction analysis indicates a double heteroepitaxial structure of AlN (0001)/NiO(111)/sapphire (0001) with the epitaxial relationship of AlN [10-10] ‖ NiO [11-2] ‖ sapphire [11-20]. The surface morphology of room-temperature grown AlN thin films was found to be atomically smooth and nanostepped, reflecting the surface of the ultrasmooth sapphire substrate with 0.2-nm-high steps.

PHOTOLUMINESCENCE OF BIEXCITON IN ZnO EPITAXIAL THIN FILMS

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3611-3614 ◽  
Author(s):  
KENSUKE MIYAJIMA ◽  
AISHI YAMAMOTO ◽  
TAKENARI GOTO ◽  
HANG JU KO ◽  
TAKAFUMI YAO
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Sapphire Substrate ◽  
Lattice Mismatch ◽  
Zno Films ◽  
Epitaxial Thin Films ◽  
Excitation Spectra ◽  
Temporal Dependence ◽  
First Time ◽  
Gan Buffer Layer

We have measured excitation dependence of photoluminescence (PL) spectra, excitation spectra of PL (PLE) and temporal dependence of the PL intensity in ZnO epitaxial thin films. The ZnO films were grown on a sapphire substrate with a GaN buffer layer to reduce a lattice mismatch. We succeeded in observing a PL due to biexciton for the first time in ZnO epitaxial thin films.

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