All Epitaxial Babi4Ti4O15 - LaNiO3 Heterostructures

1998 ◽  
Vol 541 ◽  
Author(s):  
K. M. Satyalakshmi ◽  
A. Pignolet ◽  
M. Alexe ◽  
N. D. Zakharov ◽  
C. Harnagea ◽  
...  

AbstractBismuth-based layer-structured ferroelectric oxides are gaining much attention for ferroelectric thin film applications due to their low fatigue. Epitaxial thin films of these layered ferroelectric oxides grown on epitaxial perovskite-type conducting oxide electrodes such as LaNiO3 are known to further improve the fatigue resistance. In this paper the ferroelectric properties of BaBi4Ti4O15films grown by pulsed laser deposition on epitaxial LaNiO3/SrTiO3(100) and LaNiO3/YSZ/Si(100) substrates are presented. BaBi4Ti4O15thin films with mixed a - and c - orientation exhibit ferroelectric hysteresis loops with a remanent polarization Pr of 2 μC/cm2and a coercive field Ec of about 75 kV/cm. The effect of the deposition parameters on thin film orientation, morphology and the ferroelectric properties of BBiT are discussed.

2001 ◽  
Vol 688 ◽  
Author(s):  
J. Rodríguez Contreras ◽  
J. Schubert ◽  
U. Poppe ◽  
O. Trithaveesak ◽  
K. Szot ◽  
...  

AbstractWe have prepared single crystalline epitaxial PbZr0.52Ti0.48O3 (PZT) and BaTiO3 (BTO) thin films on single crystalline epitaxial SrRuO3 (SRO) thin films grown on SrTiO3 (100) (STO) substrates. PZT and SRO thin films were grown using high-pressure on-axis sputtering and BTO using pulsed laser deposition (PLD). The film thickness ranged between 12 to 165 nm. Their excellent structural properties, surface smoothness and interface sharpness were demonstrated by X-Ray Diffraction measurements (XRD), High Resolution Transmission Electron Microscopy (HRTEM) and Atomic Force Microscopy (AFM). Rutherford Backscattering Spectrometry and Channeling measurements (RBS/C) were used to analyze stoichiometry and crystalline quality. Ferroelectric hysteresis loops were obtained for all films of a thickness down to 12 nm showing a decrease in the remanent polarization Pr and an increase in the coercive field Ec towards thinner film thicknesses. Furthermore we have prepared tunneling junctions with a PZT or BTO barrier thickness of 3-6 nm. Reproducible bi-stable I-V-curves and bias dependence of the conductance were obtained suggesting an influence of the ferroelectric properties of the barrier material on the tunnel current.


2006 ◽  
Vol 966 ◽  
Author(s):  
Seiji Nakashima ◽  
Kwi-Young Yun ◽  
Yoshitaka Nakamura ◽  
Masanori Okuyama

ABSTRACTMultiferroic BiFeO3 thin films have been prepared on Pt/TiO2/SiO2/thick (200 μm) and membrane (15 μm) Si substrate by pulsed laser deposition (PLD) to confirm the influence of stress from substrate. Si membrane was obtained by etching using reactive ion etching (RIE) until thickness is to be 15 μm. The X-ray diffraction peaks of BiFeO3 thin film on Pt/TiO2/SiO2/Si (15 μm) membrane substrate slightly shift to lower angles, compared to those on Pt/TiO2/SiO2/Si (200 μm) substrate. Ferroelectric hysteresis loops were also measured at 150 K before and after Si etching by RIE. The BiFeO3 thin film on the Pt/TiO2/SiO2/Si (15 μm) membrane structure shows remanent polarization (Pr) of 95 μC/cm2 for a maximum applied voltage of 18 V, which is larger than Pr = 71 μC/cm2 of BiFeO3 thin film on Pt/TiO2/SiO2/Si (200 μm) substrate at the same measurement conditions. Under magnetic field of 1.1 T, remanent polarization (Pr) of BiFeO3 thin film on Pt/TiO2/SiO2/Si (15 μm) membrane structure increased from 95 μC/cm2 to 101 μC/cm2 at 150 K due to stress relaxation of BiFeO3 thin film.


2007 ◽  
Vol 14 (02) ◽  
pp. 229-234
Author(s):  
SARAWUT THOUNTOM ◽  
MANOCH NAKSATA ◽  
KENNETH MACKENZIE ◽  
TAWEE TUNKASIRI

Lead zirconate titanate (PZT) films with compositions near the morphotropic phase boundary were fabricated on Pt (111)/ Ti / SiO 2/ Si (100) using the triol sol–gel method. The effect of the pre-heating temperature on the phase transformations, microstructures, electrical properties, and ferroelectric properties of the PZT thin films was investigated. Randomly oriented PZT thin films pre-heated at 400°C for 10 min and annealed at 600°C for 30 min showed well-defined ferroelectric hysteresis loops with a remnant polarization of 26.57 μC/cm2 and a coercive field of 115.42 kV/cm. The dielectric constant and dielectric loss of the PZT films were 621 and 0.0395, respectively. The microstructures of the thin films are dense, crack-free, and homogeneous with fine grains about 15–20 nm in size.


2010 ◽  
Vol 177 ◽  
pp. 197-200
Author(s):  
X.A. Mei ◽  
Min Chen ◽  
K.L. Su ◽  
A.H. Cai ◽  
J. Liu ◽  
...  

Eu2O3-doped bismuth titanate (Bi1-xEuxTi3O12: BET) thin films with random oriention were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique, and the structures and ferroelectric properties of the films were investigated. XRD studies indicated that all of BET films consisted of single phase of a bismuth-layered structure with well-developed rod-like grains. For samples with x=0.0 , 0.25, 1.0 and 1.25, I-E characteristics exhibited negative differential resistance behaviors and their ferroelectric hysteresis loops were characterized by large leakage current, whereas for samples with x=0.5 and 0.75, I-E characteristics were simple ohmic behaviors and their ferroelectric hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization (Pr) and coercive field (Ec) of the BET Film with x=0.75 were above 30μC/cm2 and 85KV/cm , respectively.


2010 ◽  
Vol 434-435 ◽  
pp. 281-284
Author(s):  
Min Chen ◽  
A.H. Cai ◽  
X.A. Mei ◽  
K.L. Su ◽  
Chong Qing Huang ◽  
...  

Pr6O11-doped bismuth titanate (BixPryTi3O12: BPT) thin films with random oriention were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique, and the structures and ferroelectric properties of the films were investigated. XRD studies indicated that all of BPT films consisted of single phase of a bismuth-layered structure with well-developed rod-like grains. For samples with y=0.06, 0.3, 1.2 and 1.5, ferroelectric hysteresis loops were characterized by large leakage current, whereas for samples with y=0.6 and 0.9, ferroelectric hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization ( Pr ) and coercive field (Ec) of the BPT Film with y=0.9 were above 35μC/cm2 and 80KV/cm , respectively. After 3×1010 switching cycles, 20% degradation of 2Pr is observed in the film with y=0.9.


2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
A. Fernández Solarte ◽  
N. Pellegri ◽  
O. de Sanctis ◽  
M. G. Stachiotti

Na0.5K0.5NbO3 (NKN) thin films were prepared by a chelate route which offers the advantage of a simple and rapid solution synthesis. The route is based on the use of acetoin as a chelating agent. The process was optimized by investigating the effects of alkaline volatilization on film properties. While we observed no evidence of stoichiometry problems due to potassium volatilization loss during the heat treatments, thin films synthesized with insufficient sodium excess presented a potassium-rich secondary phase, which has a significant influence on the ferroelectric properties. We show that the amount of spurious phase decreases with increasing Na+ concentration, in such a way that a 20 mol% Na+ excess is necessary to fully compensate the volatilization loss that occurred during the heat treatment. In this way, NKN thin films annealed at 650°C presented a well-crystallized perovskite structure, no secondary phases, well-defined ferroelectric hysteresis loops (Pr~9 μC/cm2, EC~45 kV/cm), and low leakage current density (2×10-7 A/cm2 at 80 kV/cm).


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.


2014 ◽  
Vol 633 ◽  
pp. 370-373
Author(s):  
Chong Qing Huang ◽  
X.A. Mei ◽  
M. Chen ◽  
B. Li

Pr2O3-doped bismuth titanate (Bi4-xPrxTi3O12: BPT) thin films with random oriention were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique, and the structures and ferroelectric properties of the films were investigated. XRD studies indicated that all of BPT films consisted of single phase of a bismuth-layered structure with well-developed rod-like grains. For samples with x=0..0 , 0.25, 1.0 and 1.25, I-E characteristics exhibited negative differential resistance behaviors and their ferroelectric hysteresis loops were characterized by large leakage current, whereas for samples with x=0.5 and 0.75, I-E characteristics were simple ohmic behaviors and their ferroelectric hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization ( Pr ) and coercive field (Ec) of the BPT Film with x=0.75 were above 30μC/cm2 and 75KV/cm , respectively.


1996 ◽  
Vol 11 (10) ◽  
pp. 2588-2593 ◽  
Author(s):  
Majed S. Mohammed ◽  
Ratna Naik ◽  
Joseph V. Mantese ◽  
Norman W. Schubring ◽  
Adolph L. Micheli ◽  
...  

Thin films of BaxSr1−xTiO3 (x = 0.7, 0.8, 0.9, and 1.0) were prepared by metalorganic decomposition (MOD). The relative permittivity, dissipation, polarization, resistivity, and grain size of these films were studied as a function of composition and temperature. Ferroelectric hysteresis loops were observed for all values of x and were found to be independent of measurement temperature though strongly dependent upon grain size.


2017 ◽  
Vol 744 ◽  
pp. 417-421
Author(s):  
Ya Ping Wang ◽  
Zhuo Wang ◽  
Da Ji Li ◽  
Ya Nan Cui ◽  
Zhi Juan Li

0.82NBT-0.18ST and 0.85NBT-0.15ST thin films have been prepared on Si substrates by a modified metalorganic solution deposition process. To achieve films with better ferroelectric properties, three main items have been changed in the process. Then the crystal structures, surface microstructures, hysteresis loops, fatigue curves and capacitance-voltage curves of the films were measured. It can be found that NBT-ST films can crystallize well after annealing at 650 °C for 5 minutes and have smooth surface microstructures. The 0.85NBT-0.15ST thin films exhibit better well-defined hysteresis loops than 0.82NBT-0.18ST, with a remnant polarization of 1.1 mC/cm2 and a coercive fields of 44.2 kV/cm. The clockwise C-V curves show that they have a desired polarization-type switching mode. The memory window of 0.82NBT-0.18ST thin film is about 1.8V, and that of 0.85NBT-0.15ST thin film is about 2.5V.


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