Preparation and Microstructural Characterization of Ferroelectric Thin Film PbTiO3 on Si, MgO, and Sapphire Deposited by DC Reactive Multitarget Co-Sputtering.

1991 ◽  
Vol 243 ◽  
Author(s):  
K.Y. Kim ◽  
H.I. Hwang ◽  
J.Y. Lee ◽  
W.K. Choo

AbstractPbTiO3 thin films on Si (100) plane were prepared by the DC reactive multitarget cosputtering technique. The film composition and structure were examined as a function of deposition parameters. The crystal structure and microstructure of PbTiO3 thin film deposited on Si at low substrate temperature of 200°C were examined as a fuction of post-annealing temperature by X-ray diffraction and transmission electron microscopy.The ferroelectric domain configurations were analyzed by plane-view TEM. The preferred orientation of PbTiO3 thin films deposited on MgO (100) and sapphire (1102) at high substrate temperature of 520°C were also examined.

2003 ◽  
Vol 775 ◽  
Author(s):  
Donghai Wang ◽  
David T. Johnson ◽  
Byron F. McCaughey ◽  
J. Eric Hampsey ◽  
Jibao He ◽  
...  

AbstractPalladium nanowires have been electrodeposited into mesoporous silica thin film templates. Palladium continually grows and fills silica mesopores starting from a bottom conductive substrate, providing a ready and efficient route to fabricate a macroscopic palladium nanowire thin films for potentially use in fuel cells, electrodes, sensors, and other applications. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicate it is possible to create different nanowire morphology such as bundles and swirling mesostructure based on the template pore structure.


1998 ◽  
Vol 545 ◽  
Author(s):  
J. C. Caylor ◽  
A. M. Stacy ◽  
T. Sands ◽  
R. Gronsky

AbstractBulk skutterudite phases based on the CoAs3 structure have yielded compositions with a high thermoelectric figure-of-merit (“ZT”) through the use of doping and substitutional alloying. It is postulated that further enhancements in ZT may be attained in artificially structured skutterudites by engineering the microstructure to enhance carrier mobility while suppressing the phonon component of the thermal conductivity. In this work the growth and properties of singlephase CoSb3 and IrSb3 skutterudite thin films are reported. The films are synthesized by pulsed laser deposition (PLD) where the crystallinity can be controlled by the deposition temperature. Powder X-ray diffraction (PXRD), Transmission electron microscopy (TEM) and Rutherford- Back Scattering (RBS) were used to probe phase, structure, morphology and stoichiometry of the films as functions of growth parameters and substrate type. A substrate temperature of 250°C was found to be optimal for the deposition of the skutterudites from stoichiometric targets. Above this temperature the film is depleted of antimony due to its high vapor pressure eventually reaching a composition where the skutterudite structure is no longer stable. However, when films are grown from antimony-rich targets the substrate temperature can be increased to at least 350°C while maintaining the skutterudite phase. In addition, adhesion properties of the films are explored in terms of the growth mode and substrate interaction. Finally, preliminary room temperature electrical and thermal measurements are reported.


2013 ◽  
Vol 313-314 ◽  
pp. 254-257
Author(s):  
Ling Fang Jin ◽  
Hong Zhuang

Nonepitaxially grown FePt (x)/FePt:C thin films were synthesized, where FePt (x) (x=2, 5, 8, 11, 14 nm) layers were served as underlayers and FePt:C layer was nanocomposite with thickness of 5 nm. The effect of FePt underlayer on the ordering, orientation and magnetic properties of FePt:C thin films has been investigated by adjusting FePt underlayer thicknesses from 2 nm to 14 nm. X-ray diffraction (XRD), together with transmission electron microscopy (TEM) confirmed that the desired L10 phase was formed and films were (001) textured with FePt underlayer thickness decreased less 5 nm. For 5 nm FePt:C nanocomposite thin film with 2 nm FePt underlayer, the coercivity was 8.2 KOe and the correlation length of FePt:C nanocomposite film was 67 nm. These results reveal that the better orientation and magnetic properties for FePt:C nanocomposite films can be tuned by decreasing FePt underlayer thickness.


1991 ◽  
Vol 230 ◽  
Author(s):  
Hideo Miura ◽  
En Ma ◽  
Carl V. Thompson

AbstractThe initial phase formation sequence for reactions in cobalt/ amorphous-silicon multi-layer thin films has been investigated using a combination of differential scanning calorimetry, thin film X-ray diffraction, and transmission electron microscopy. Multilayer thin films with various overall atomic concentration ratios and various bilayer thicknesses were used in this study. It was found that crystalline CoSi is always the first phase to nucleate in the interdiffused amorphous layer which preexisted at the as-deposited coba It/amorphous-si licon interface. The CoSi nucleates at temperatures as low as about 530 K, but does not grow until the next phase, which is Co2 Si when excess Co is available, starts to nucleate and grow. The activation energy of the CoSi nucleation was found to be 1.-6±0.1 eV.


2007 ◽  
Vol 14 (04) ◽  
pp. 755-759 ◽  
Author(s):  
D. U. LEE ◽  
J. H. JUNG ◽  
T. W. KIM ◽  
H. S. LEE ◽  
H. L. PARK ◽  
...  

CdTe thin films were grown on GaAs (100) substrates by using molecular beam epitaxy at various temperatures. The results of the X-ray diffraction (XRD) patterns showed that the orientation of the grown CdTe thin films was the (100) orientation. XRD patterns, atomic force microscopy images, high-resolution transmission electron microscopy (HRTEM) images, and photoluminescence spectra showed that the crystallinity of CdTe (100) epilayers grown on GaAs (100) substrates was improved by increasing the substrate temperature. HRTEM images showed that misfit dislocations existed at the CdTe / GaAs heterointerface. These results can help improve understanding of the substrate temperature effect on the structural and the optical properties of CdTe (100)/ GaAs (100) heterostructures.


2007 ◽  
Vol 558-559 ◽  
pp. 975-978
Author(s):  
L.V. Tho ◽  
K.E. Lee ◽  
Cheol Gi Kim ◽  
Chong Oh Kim ◽  
W.S. Cho

Nanocrystalline CoFeHfO thin films have been fabricated by RF sputtering method. Co52Fe23Hf10O15 thin film is observed, exhibit good magnetic properties with magnetic coercivity (Hc) of 0.18 Oe; anisotropy fild (Hk) of 49 Oe; saturation magnetization (4лMs) of 21 kG, and electrical resistivity (ρ) of 300 01cm. The frequency response of permeability of the film is excellent. The effect of microstructure on the electrical and magnetic properties of thin film was studied using X-ray diffraction (XRD) analysis and conventional transmission electron microscopy (TEM). The results showed that excellent soft magnetic properties were associated with granular nannoscale grains of α-CoFe and α-Co(Fe) phases.


2002 ◽  
Vol 721 ◽  
Author(s):  
Masaaki Futamoto ◽  
Kouta Terayama ◽  
Katsuaki Sato ◽  
Nobuyuki Inaba ◽  
Yoshiyuki Hirayama

AbstractConditions to prepare good single-crystal CoCrPt magnetic thin film with the easy magnetization axis perpendicular to the film plane were investigated using oxide single-crystal substrates, Al2O3(0001), LaAlO3(0001), mica(0001), SrTiO3(111), and MgO(111). The best CoCrPt(0001) single-crystal thin film was obtained on an Al2O3(0001) substrate employing a non-magnetic CoCrRu underlayer. The crystallographic quality of single-crystal thin film was investigated using X-ray diffraction and high-resolution transmission electron microscopy. Some intrinsic magnetic properties (Hk, Ku) were determined for the single-crystal CoCrxPty thin films for a compositional range of x=17-20at% and y=0-17at%.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Pallabi Phukan ◽  
Dulen Saikia

CdSe quantum dots (QDs) dispersed in polyvinyl alcohol (PVA) matrix with their sizes within the quantum dot regime have been synthesized via a simple heat induced thermolysis technique. The effect of the concentrations of the cadmium source on the optical properties of CdSe/PVA thin films was investigated through UV-Vis absorption spectroscopy. The structural analysis and particle size determination as well as morphological studies of the CdSe/PVA nanocomposite thin films were done with the help of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD analysis reveals that CdSe/PVA nanocomposite thin film has a hexagonal (wurtzite) structure. A prototype thin film solar cell of CdSe/CdTe has been synthesized and its photovoltaic parameters were measured.


2003 ◽  
Vol 18 (2) ◽  
pp. 423-432 ◽  
Author(s):  
G.F. Iriarte ◽  
F. Engelmark ◽  
M. Ottosson ◽  
I.V. Katardjiev

In this work, a systematic study of the influence of five deposition parameters, i.e., process pressure, substrate temperature, target power, and substrate bias, as well as gas composition on the residual stress in fully textured polycrystalline aluminum nitride thin films deposited on Si(100) wafers using the reactive sputtering method was performed. Post-growth residual stress measurements were obtained indirectly from radius of curvature measurements of the wafer prior to and after deposition. Two different techniques were used to determine the curvature: an optically levered laser beam and an x-ray diffraction method. Stresses in both cases were then evaluated using the Stoney formulation [G.G. Stoney, Proc. R. Soc. (London)A82,172 (1909)]. Both methods give similar results, with slight quantitative differences. The existence of a transition region between tensile and compressive stress previously reported in the literature is also confirmed. The transition is shown to be strongly dependent on the process parameters. Optimal films regarding stress were grown at 2 mtorr, 900 W at the target, a 20/45 Ar/N2gas mixture, and floating potential at the substrate. The substrate temperature did not influence the measured internal stress in the films.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Yuan-Tsung Chen ◽  
S. M. Xie

C40Fe40B20was deposited on a glass substrate to a thickness (tf) of between 100 Å and 500 Å. X-ray diffraction patterns (XRD) indicate thatC40Fe40B20films are in an amorphous state. The plane-view microstructures and grain size distributions of CoFeB thin films are observed under a high-resolution transmission electron microscope (HRTEM). The thicker CoFeB films have larger grain size distribution than thinner CoFeB films. The saturation magnetization (Ms) exhibits a size effect, meaning thatMsincreases astfincreases. The magnetic remanence magnetization (Mr) of CoFeB thin films are sensitive to thinner CoFeB films, and the refined grain size of thinner CoFeB films can induce ferromagnetic stronger spin exchange-coupling behavior than thicker CoFeB films, resulting in higher remanence. The highest magnetic squareness ratio (Mr/Ms) of the CoFeB films occurs at thickness of 100 Å, suggesting the 100 Å of the as-deposited CoFeB film is suitable for magnetic memory application. These results also demonstrate that coercivity (Hc) is increased by an increase in the width of the distribution of grain sizes. The electrical resistivity (ρ) of such a film is typically higher than normally exceeding 100 μΩ cm, revealing that the amorphous phase dominates. These results are consistent with the XRD results.


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