Effect of Bottom Electrodes on Structural and Electrical Properties of Laser Ablated SrBi2Ta2O9 Thin Films

2001 ◽  
Vol 688 ◽  
Author(s):  
Rasmi R. Das ◽  
W. Pérez ◽  
P. Bhattacharya ◽  
Ram. S. Katiyar
Keyword(s):  
Thin Films ◽  
Barrier Height ◽  
Ferroelectric Properties ◽  
High Resistivity ◽  
Emission Model ◽  
X Ray Diffraction ◽  
Oxide Electrodes ◽  
Maximum Value ◽  
Structural And Electrical Properties ◽  
Raman Modes

AbstractWe have grown SrBi2Ta2O9 (SBT) thin films on various bottom electrodes such as Pt/TiO2/SiO2/Si (Pt) and LaNiO3/Pt/TiO2/SiO2/Si (LNO) substrates. The substrate temperature and oxygen pressure for the SBT film was maintained at 500 °C and 200 mTorr. As-grown films were post-annealed at a temperature of 800 °C. X-ray diffraction studies revealed that as-grown films were amorphous and crystallized to single phase after annealing. The difficulty of obtaining lowest Raman modes of SBT on platinized silicon substrate was overcome by using conducting oxide electrodes. Films grown on platinized silicon showed maximum value of remanent polarization (2Pr ∼ 21.5 μC/cm2) with coercive field (Ec) of ∼ 67 kV/cm. The degradation of ferroelectric properties of the films was observed with the introduction of 50 nm conducting LaNiO3 electrode at the interface of Pt and SBT film, which was attributed to high resistivity of the oxide electrode layers. Leakage current density was studied with the consideration of the Schottky emission model. The barrier height of the films grown on Pt and LNO were estimated to be 1.27 eV and 1.12 eV, respectively. The reduction of barrier height was attributed to the lower work function of the LNO electrode.

Effect of Cationic Substitution on Raman Spectra of SrBi2Ta2O9Ceramics and Thin Films

2003 ◽  
Vol 784 ◽  
Author(s):  
W. Perez ◽  
R. R. Das ◽  
P. S. Dobal ◽  
Y. I. Yuzyuk ◽  
P. Bhattacharya ◽  
...  
Keyword(s):  
Thin Films ◽  
Transition Temperature ◽  
Lattice Mismatch ◽  
Ferroelectric Properties ◽  
Low Frequency ◽  
X Ray Diffraction ◽  
Ionic Radii ◽  
Cationic Substitution ◽  
Factor Substitution ◽  
Raman Modes

ABSTRACTIn the present work micro-Raman spectroscopy has been used to understand the lattice dynamics of cation substituted SBT ceramics and thin films. Different concentrations of Ca and V were introduced into SBT lattices. Incorporation of Ca ion at Sr-site was confirmed by decrease in the lattice parameters calculated from x-ray diffraction data. The lowest Raman modes at 27 cm-1and 58 cm-1showed upward shift with increasing Ca concentration and was attributed to the lower mass and lower ionic radii of Ca. The temperature dependant Raman studies revealed the increase of the phase transition temperature with increased Ca content, and was attributed to the decrease in tolerance factor. Substitution of smaller cation at Sr site in SBT compound has increased lattice mismatch between SrO and TaO2planes inside the stable perovskite unit of SrTa2O7which has pronounced influence on ferroelectric properties of SBT. Substitution of vanadium at Ta-site of SBT did not influence the low frequency Raman modes of SBT. However, it showed a pronounced influence on the O-Ta-O stretching modes by splitting the mode frequency at 810 cm-1. The transition temperature of SBT was reduced with increasing vanadium contents.

Structural and Ferroelectric Properties of Bi4-xNixTi3O12 Thin Films by Sol-Gel Process

2006 ◽  
Vol 966 ◽  
Author(s):  
Ricardo Melgarejo ◽  
Maharaj S Tomar ◽  
Rahul Singhal ◽  
Ram S Katiyar
Keyword(s):  
Thin Films ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Low Frequency ◽  
X Ray Diffraction ◽  
Coating Materials ◽  
Low Field ◽  
Sol Gel Process ◽  
Raman Modes ◽  
Ferroelectric Memories

ABSTRACTNickel-substituted Bi4Ti3O12 (i.e., Bi4-xNixTi3O12) were synthesized by sol-gel process for different compositions. Thin films were deposited on Pt (i.e., Pt/TiO2/SiO2/Si) substrate by spin coating. Materials were characterized by x-ray diffraction and Raman spectroscopy. This study indicates that the material makes a solid solution for the compositions: x = 0.00, 0.05, 0.10, 0.15, 0.20, and 0.30, where a Ni ion replaces the Bi site. The prominent effect of Ni substitution was observed in low-frequency Raman modes. Sol-gel derived thin films of Bi4-xNixTi3O12 on a Pt substrate and post annealed at 700°C were tested for ferroelectric response which showed high remnant polarization (Pr = 22 μC/cm2 for x = 0.15). The leakage current (less then 10−7 A/cm2) at low field was observed in the film with composition x = 0.15 .The polarization of the BNiT (x = 0.15) film decreased to 83% of the initial value after 1×109 switching cycles These results indicate the potential application of Ni substituted bismuth titanate films in non-volatile ferroelectric memories.

Analyzed by Kelvin Force Microscopy of PbZr0.3Ti0.7O3 Thin Films Grown on La0.5Sr0.5CoO3 or LaMnO3 Bottom Electrodes

2006 ◽  
Vol 306-308 ◽  
pp. 1295-1300
Author(s):  
J.S. Choi ◽  
J.S. Kim ◽  
I.S. Byun ◽  
B.H. Park
Keyword(s):  
Thin Films ◽  
Deposition Time ◽  
Ferroelectric Properties ◽  
X Ray Diffraction ◽  
Pzt Thin Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
Structural And Electrical Properties ◽  
Ferroelectric Domains ◽  
Pzt Films

We have investigated structural and electrical properties of PbZr0.3Ti0.7O3 (PZT) thin films deposited by pulsed laser deposition methods. In order to improve the ferroelectric properties of PZT thin films, we have controlled grain size or surface morphology by changing bottom electrode or deposition time. PZT thin films have been deposited on La0.5Sr0.5CoO3 (LSCO) or LaMnO3 (LMO) bottom electrodes with LaAlO3 substrates during different deposition times. X-ray diffraction data have shown that all the PZT films and bottom electrodes are highly oriented with their c-axes normal to the substrates. The thickness of each film is determined by field-emission scanning electron microscope. We have also observed alternation of grain sizes (80~180 nm) by using atomic force microscopy mode and surface potential distribution and retention behavior of ferroelectric domains by using Kelvin force microscopy mode. A PZT/LMO structure has shown superior ferroelectric and retention properties to a PZT/LSCO structure.

Material Characteristics and Electrical Modeling of Ultra Thin Copper Oxides in ULSI Application

2007 ◽  
Vol 561-565 ◽  
pp. 1225-1228
Author(s):  
Takayuki Ohba
Keyword(s):  
Diffraction Pattern ◽  
Barrier Height ◽  
Oxide Thickness ◽  
Amorphous Structure ◽  
Emission Model ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
X Ray ◽  
Current Emission ◽  
X Ray Absorption

With the highest brilliance synchrotron radiation X-ray (SPring-8) and TEM observations, Cu oxides ranged 2-nm to 10-nm in thickness formed on sputtered Cu has been evaluated. For the plasma-assisted Cu oxide, weak Cu2O and/or CuO X-ray diffraction pattern is observed, while no diffraction pattern in native and thermally (170°C) grown oxides. Those native and thermal oxides show Cu2O coordination observed by XANES (X-ray Absorption Near Edge Structure) method. This suggests that Cu oxide formed at low temperatures consists of stoichiometric Cu2O in an amorphous structure. According to the Fowler-Nordheim (F-N) current emission model, the current emission taking place at Cu2O decreases with increasing of the oxide thickness and its mean barrier height (φB) in the MIM band structure. In case of current density at 106A/cm2 of 1V, it is estimated that the allowable thickness of Cu oxides is approximately 1.5-nm at 1 eV of barrier height.

Stress of Platinum Thin Films Deposited by Dc Magnetron Sputtering Using Argon/Oxygen Gas Mixture

1996 ◽  
Vol 441 ◽  
Author(s):  
Min Hong Kim ◽  
Tae-Soon Park ◽  
Dong-Su Lee ◽  
Yong Eui Lee ◽  
Dong-Yeon Park ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
High Resistivity ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Oxygen Incorporation ◽  
Oxygen Fraction ◽  
Oxygen Gas ◽  
Pt Films ◽  
Excessive Oxygen

AbstractPt thin films were deposited by a DC magnetron sputtering with Ar/O2 gas mixtures. Due to the oxygen incorporation into the Pt films, deposition rate and resistivity of as-deposited Pt thin films increased with oxygen fraction in the sputtering gas. No peaks from crystalline Pt oxides were observed by x-ray diffraction (XRD) and excessive oxygen incorporation into Pt lead to an amorphous Pt oxide formation. More oxygen could be incorporated in the Pt thin films deposited at lower temperatures and at higher total pressures. Incorporated oxygen was completely removed after an annealing at 800 °C for an hour in air ambient, as the resistivity of the Pt thin films recovered their bulk resistivity values. Tensile stress of the Pt films decreased with oxygen incorporation, and approached a saturation level at high resistivity of the films, presumably due to the formation of amorphous Pt oxides.

Structural and Electrical Properties of Colossal Magnetoresistive LSMO Thin Films Prepared by KrF Laser Ablation Method

2001 ◽  
Vol 666 ◽  
Author(s):  
Fumiaki Mitsugi ◽  
Tomoaki Ikegami ◽  
Kenji Ebihara ◽  
Jagdish Narayan ◽  
Alexander M. Grishin
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Electrical Properties ◽  
Lattice Mismatch ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
X Ray ◽  
Colossal Magnetoresistive ◽  
Laser Ablation Method ◽  
Structural And Electrical Properties

ABSTRACTWe prepared colossal magnetoresistive La0.8Sr0.2MnO3 thin films on the MgO, SrTiO3 and LaAlO3 single crystal substrates using KrF excimer pulsed laser ablation technique. The structural and electrical properties of the La0.8Sr0.2MnO3 thin films which were strained by the lattice mismatch are reported. The in-plane lattice mismatch between the La0.8Sr0.2MnO3 and MgO, SrTiO3 and LaAlO3 substrates are -7.8 %, -0.5 % and +2.3 %, respectively. The X-ray diffraction spectra of the films exhibited c-axis orientation. In the case of the La0.8Sr0.2MnO3 / LaAlO3 thin films with thickness over 100 nm, the divided (00l) peaks were observed. The surface morphology and transport property of the strongly stressed La0.8Sr0.2MnO3 / LaAlO3 were different from those of La0.8Sr0.2MnO3 / MgO and La0.8Sr0.2MnO3 / SrTiO3thin films.

EFFECT OF GRAIN SIZE ON THE FERROELECTRIC PROPERTIES OF Bi3.25La0.75Ti3O12 Thin Films

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4469-4474 ◽  
Author(s):  
KYOUNG-TAE KIM ◽  
CHANG-IL KIM ◽  
DONG-HEE KANG ◽  
IL-WUN SHIM
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Fatigue Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Current Densities ◽  
Metalorganic Decomposition ◽  
Small Grains

The Bi 3.25 La 0.75 Ti 3 O 12 (BLT) thin films were prepared by metalorganic decomposition method. The effect of grain size on the ferroelectric properties during crystallization were investigated by x-ray diffraction and field emission scanning electron microscope. The grain size and the roughness of BLT films increase with increasing of drying temperature. The leakage current densities of the BLT thin film with large grains are higher than that with small grains. The remanent polarization of BLT increase with increasing grain size. As compared BLT with small grain size, the BLT film with larger grain size shows better fatigue properties. This may be explained that small grained films shows more degradation of switching charge than large grained films.

Structural and Vibrational Properties of Ferroelectric Pb1-xSrxTiO3 Thin Films and Powders

2002 ◽  
Vol 748 ◽  
Author(s):  
M. Jain ◽  
A. Savvinov ◽  
P. S. Dobal ◽  
S. B. Majumder ◽  
R. S. Katiyar ◽  
...  
Keyword(s):  
Thin Films ◽  
Soft Mode ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Vibrational Properties ◽  
X Ray Diffraction ◽  
Phase Transition Temperatures ◽  
Induced Changes ◽  
Pst System

ABSTRACTIn this work we present the structural, and vibrational properties of ferroelectric Pb1-xSrxTiO3 (PST). Thin films of PST were prepared by using sol-gel technique for various compositions with x values ranging from 0.0–1.0. Respective compositions were also prepared in ceramic and powder forms using sol-gel and solid-state reaction methods. X-ray diffraction was used for the structural characterization of these materials. Raman spectroscopy was utilized to study the phases and lattice vibrational modes, especially the soft mode in PST compositions. The temperature dependence of the soft mode frequency for different PST compositions revealed that the phase transition temperatures increased with increasing Pb contents in PST system. Ferroelectric properties of the films were correlated with the substitution-induced changes in the material.

Low Temperature Aqueous Polymeric Precursor Processing of ZnO:Er Using a Glycerol Chelating Agent

2006 ◽  
Vol 957 ◽  
Author(s):  
Uma Choppali ◽  
Brian P Gorman
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Doping Concentration ◽  
Compressive Strain ◽  
Chelating Agent ◽  
X Ray Diffraction ◽  
Er Doping ◽  
Structural And Electrical Properties ◽  
Different Temperatures ◽  
Surface Modified

ABSTRACTErbium doped ZnO (ZnO:Er) is considered to be a suitable candidate for fabrication of the current injection optical devices. Although ZnO: Er thin films have been synthesized previously by pulsed laser deposition, we present low – temperature processed ZnO:Er thin films from polymeric precursors. In this work, we study the effect of variation of Er doping concentration on the structural and electrical properties of the synthesized films. ZnO nanoparticles of varied Er doping concentration, derived from the prepared polymeric solution, has been spin – coated onto surface modified substrates, and annealed at different temperatures. The effect of Er doping concentration on film grain size and strain was analyzed using X-ray diffraction. XRD data reveals that doping of Er ions reduces compressive strain considerably in the films. It is speculated that the presence of larger Er cations in ZnO cause tensile stress, which neutralizes the inherent compressive stress, observed in undoped ZnO, significantly decreasing and hence, making the films stress free. Crystallite size of ZnO:Er thin films, annealed at 600°C, was calculated to be approximately 12 nm using Scherrer's equation. The surface morphology of the thin films was characterized by both SEM and AFM. Electrical resistivity of the films, annealed at 450oC, was calculated to be 290 Ω-m for 5 at wt% and 125 Ω-m for 10 at wt% ZnO:Er films.

Preparation and Electrical Properties of Bi0.9Nd0.1Fe0.925Mn0.075O3 Thin Films

2012 ◽  
Vol 557-559 ◽  
pp. 1933-1936
Author(s):  
Ning Yan ◽  
Sheng Hong Yang ◽  
Yue Li Zhang
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray ◽  
Low Leakage ◽  
Bifeo3 Thin Films ◽  
Low Leakage Current

Pure BiFeO3(BFO) and Bi0.9Nd0.1Fe0.925Mn0.075O3(BNFM) thin films were deposited on Pt(111)/Ti/SiO2/Si substrate by sol-gel method. X-ray diffraction analysis showed that all the films were single perovskite structure and a phase transition appeared in Nd–Mn codoped BiFeO3 thin films. Electrical measurements indicated that the ferroelectric properties of BFO thin films were significantly improved by Nd and Mn codoping. BNFM films exhibit a low leakage current and a good P-E hysteresis loop. The remanent polarization (Pr) value of 74μC/cm2has been obtained in BNFM films, while the coercive field (Ec) is 184kV/cm.

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