Preparation and Characterization of a- and b-Axis-Oriented Epitaxially Grown Bi4Ti3O12-Based Thin Films on Rutile-Type Oxides

2001 ◽  
Vol 688 ◽  
Author(s):  
Takayuki Watanabe ◽  
Keisuke Saito ◽  
Minoru Osada ◽  
Hiroshi Funakubo

Abstracta- and b-axis-oriented epitaxial Bi4Ti3O12 films were prepared on (101)TiO2 substrates (rutile) at 600°C by metalorganic chemical vapor deposition (MOCVD). Subsequently, the same films were similarly prepared on (101)-oriented conductive materials with the same rutile structure and similar lattice parameters as TiO2, such as RuO2 and IrO2. Their perfect epitaxial growth was confirmed by several X-ray diffraction measurements. RuO2 and IrO2 were deposited on not only structurally equivalent (101)RuO2//(101)TiO2 and (101)IrO2//(101)TiO2 structures, but were also successfully deposited on the corundum (012)Al2O3 and (110)Al2O3 single crystals by the MOCVD and rf-sputtering method, respectively. A well-saturated P-E hysteresis with a remanent polarization above 20 μC/cm2 was observed for a- and b-axis-oriented Bi4Ti3O12-based materials, (Bi4−xNdx)(Ti3−yVy)O12 (BNTV), that were epitaxially grown on rutile-rutile and rutile-corundum stacking structures. These results should enable broader application of the bismuth layer-structured ferroelectrics.

2002 ◽  
Vol 748 ◽  
Author(s):  
Keisuke Saito ◽  
Toshiyuki Kurosawa ◽  
Takao Akai ◽  
Shintaro Yokoyama ◽  
Hitoshi Morioka ◽  
...  

ABSTRACT200-nm-thick Pb(Zrx,Ti1-x)O3 (PZT) thin films with zirconium composition in the range from 0% to 65% were epitaxially grown on (001)c SrRuO3 (SRO)//SrTiO3 (STO) single crystal substrates by pulsed metalorganic chemical vapor deposition (pulsed MOCVD). Constituent crystallographic phases were characterized by high-resolution X-ray diffraction reciprocal space mapping. It was found that PZT thin films having zirconium composition from 45% to 60% show mixed tetragonal and pseudocubic phases and their lattice parameters remained constant in this composition range.


2005 ◽  
Vol 902 ◽  
Author(s):  
Yong Kwan Kim ◽  
Shintaro Yokoyama ◽  
Risako Ueno ◽  
Hitoshi Morioka ◽  
Osami Sakata ◽  
...  

AbstractWe performed x-ray diffraction measurements by using highly brilliant synchrotron radiation on epitaxial Pb(Zr0.35Ti0.65)O3 film capacitor structures. Small regions of 300-nm-thick epitaxial Pb(Zr,Ti)O3 thin films with Pt and SrRuO3 top electrodes were measured after applying various numbers of switching cycles of the electric field. Epitaxial Pb(Zr,Ti)O3 thin films were prepared on epitaxial (100)cSrRuO3/(100)SrTiO3 substrates by pulsed-metalorganic chemical vapor deposition. The volume faction of c-domain and remanent polarization was plotted against the number of switching cycles. In the both capacitors, the Vc increased as the switching cycle increased independent of fatigue behavior.


1995 ◽  
Vol 406 ◽  
Author(s):  
M. S. Gaffneyt ◽  
C. M. Reavesl ◽  
A. L Holmes ◽  
R. S. Smith ◽  
S. P. DenBaars

AbstractMetalorganic chemical vapor deposition (MOCVD) is a process used to manufacture electronic and optoelectronic devices that has traditionally lacked real-time growth monitoring and control. We have developed control strategies that incorporate monitors as real-time control sensors to improve MOCVD growth. An analog control system with an ultrasonic concentration monitor was used to reject bubbler concentration disturbances which exist under normal operation, during the growth of a four-period GaInAs/InP superlattice. Using X-ray diffraction, it was determined that the normally occurring concentration variations led to a wider GaInAs peak in the uncompensated growths as compared to the compensated growths, indicating that closed loop control improved GaInAs composition regulation. In further analysis of the X-ray diffraction curves, superlattice peaks were used as a measure of high crystalline quality. The compensated curve clearly displayed eight orders of satellite peaks, whereas the uncompensated curve shows little evidence of satellite peaks.


2007 ◽  
Vol 539-543 ◽  
pp. 1230-1235 ◽  
Author(s):  
Hyoun Woo Kim ◽  
S.H. Shim

We have synthesized the high-density Ga2O3 nanowires on gold (Au)-coated silicon substrates using metalorganic chemical vapor deposition. The nanowires exhibited one-dimensional structures having circular cross sections with diameters in the range of 30-200 nm. The energy dispersive x-ray spectroscopy revealed that the nanowires contained elements of Ga and O, without Au-related impurities. X-ray diffraction analysis and high-resolution transmission electron microscopy showed that the Ga2O3 nanowires were crystalline.


1996 ◽  
Vol 449 ◽  
Author(s):  
Hongqiang Lu ◽  
Malathi Thothathiri ◽  
Ziming Wu ◽  
Ishwara Bhat

ABSTRACTIndium droplet formation during the epitaxial growth of InxGa1-xN films is a serious problem for achieving high quality films with high indium mole fraction. In this paper, we studied the formation of indium droplets on the InxGa1-xN films grown by metalorganic chemical vapor deposition (MOCVD) using single crystal x-ray diffraction. It is found that the indium (101) peak in the x-ray diffraction spectra can be utilized as a quantitative measure to determine the amounts of indium droplets on the film. It is shown by monitoring the indium diffraction peak that the density of indium droplets increases at lower growth temperature. To suppress these indium droplets, a modulation growth technique is used. Indium droplet formation in the modulation growth is investigated and it is revealed in our study that the indium droplets problem has been partially relieved by the modulation growth technique.


1997 ◽  
Vol 482 ◽  
Author(s):  
E. L. Piner ◽  
N. A. El-Masry ◽  
S. X. Liu ◽  
S. M. Bedair

AbstractInGaN films in the 0–50% InN composition range have been analyzed for the occurrence of phase separation. The ñ0.5 jum thick InGaN films were grown by metalorganic chemical vapor deposition (MOCVD) in the 690 to 780°C temperature range and analyzed by θ−20 x-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area diffraction (SAD). As-grown films with up to 21% InN were single phase. However, for films with 28% InN and higher, the samples showed a spinodally decomposed microstructure as confirmed by TEM and extra spots in SAD patterns that corresponded to multiphase InGaN. An explanation of the data based on the GaN-InN pseudo-binary phase diagram is discussed.


2011 ◽  
Vol 1292 ◽  
Author(s):  
Hironori Fujisawa ◽  
Masaru Shimizu ◽  
Ryohei Kuri ◽  
Seiji Nakashima ◽  
Yasutoshi Kotaka ◽  
...  

ABSTRACTPbTiO3-covered ZnO nanorods were grown on Al2O3$\left({11\bar 20} \right)$ by metalorganic chemical vapor deposition (MOCVD), and their crystalline orientation was investigated by x-ray diffraction (XRD). Structural analysis by scanning electron microscopy and XRD revealed that the hexagonal ZnO nanorods had $\left\{ {10\bar 10} \right\}$-side facets. XRD analysis of PbTiO3 thin films on ZnO$\left({10\bar 10} \right)$/Al2O3$\left({10\bar 10} \right)$revealed that PbTiO3 was epitaxially grown on ZnO$\left({10\bar 10} \right)$, showing 6 variants of crystallites with the c-axis tilted either 27o or 69o from the surface normal to the ZnO$\left({10\bar 10} \right)$ plane. Effective piezoelectric coefficients calculated for the 27o and 69o-crystallites using piezoresponse force microscopy confirm that deformation of nanorods and nanotubes contributed to the large electrically-induced strain along the radial direction.


Sign in / Sign up

Export Citation Format

Share Document