Enhancement of Ferroelectricity and Magnetoelectric Effect of BiFeO3 Thin Films on Membrane Structure

2006 ◽  
Vol 966 ◽  
Author(s):  
Seiji Nakashima ◽  
Kwi-Young Yun ◽  
Yoshitaka Nakamura ◽  
Masanori Okuyama
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Membrane Structure ◽  
Remanent Polarization ◽  
Hysteresis Loops ◽  
X Ray Diffraction ◽  
Multiferroic Bifeo ◽  
Before And After ◽  
Diffraction Peaks ◽  
Ferroelectric Hysteresis

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.

Effects of γ-Ray Irradiation on Structure and Properties of ZnO:Al Thin Film

2007 ◽  
Vol 546-549 ◽  
pp. 2137-2142 ◽  
Author(s):  
Wen Wen Wang ◽  
Tian Min Wang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
High Performance ◽  
Hall Effect Measurement ◽  
High Rate ◽  
X Ray Diffraction ◽  
Vacancy Defects ◽  
Structure Morphology ◽  
Before And After ◽  
Γ Ray

ZnO:Al(ZAO) thin film is a kind of transparent conductive functional material which has a potential application in the solar cell and Atom Oxygen resisting systems of spacecrafts. High performance ZAO thin films were prepared by reactive magnetron sputtering and then irradiated by γ-ray with different dose or rate of irradiation. The as-deposited sample and irradiated ones were characterized by X-ray Diffraction, Scanning Electron Microscopy and Hall-effect measurement to investigate the dependences of the structure, morphology and electrical properties of ZAO on the dose and rate of γ-ray irradiation. Measurement of Positron Annihilation Doppler-Broadening Spectroscopy was carried out to study the variation of the defects in ZAO thin films before and after irradiation. It is indicated that γ-ray will excite the carriers, which are electrons in ZAO. A high rate of γ-ray irradiation could slightly destroy the bonds of Zn-O and decrease the crystallinity, while the effect of low rate irradiation is similar to heat annealing and increase the crystallinity of ZAO thin films. γ-ray has no apparent influences on the negative vacancy defects in ZAO thin film.

Electrical Characteristics and Microstructures of Eu2O3-Doped Bi4Ti3O12 Thin Films

2010 ◽  
Vol 177 ◽  
pp. 197-200
Author(s):  
X.A. Mei ◽  
Min Chen ◽  
K.L. Su ◽  
A.H. Cai ◽  
J. Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Single Phase ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Differential Resistance ◽  
Rf Magnetron Sputtering ◽  
Electrical Characteristics ◽  
Si Substrates ◽  
Ferroelectric Hysteresis

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.

Ferroelectric Properties and Microstructures of Pr6O11-Doped Bi4Ti3O12 Thin Films

2010 ◽  
Vol 434-435 ◽  
pp. 281-284
Author(s):  
Min Chen ◽  
A.H. Cai ◽  
X.A. Mei ◽  
K.L. Su ◽  
Chong Qing Huang ◽  
...  
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Single Phase ◽  
Bismuth Titanate ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Rf Magnetron Sputtering ◽  
Si Substrates ◽  
Large Leakage Current ◽  
Ferroelectric Hysteresis

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.

Temperature-dependent ferroelectric properties of (Pb0.75La0.25)TiO3 thin films

2004 ◽  
Vol 19 (6) ◽  
pp. 1638-1642
Author(s):  
S.T. Zhang ◽  
J.P. Li ◽  
Y.F. Chen ◽  
Z.G. Liu ◽  
N.B. Ming
Keyword(s):  
Thin Films ◽  
Fatigue Resistance ◽  
Room Temperature ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Si Substrates ◽  
Saturated Polarization

Polycrystalline (Pb0.75La0.25)TiO3 (PLT25) thin films have been fabricated on Pt/Ti/SiO2/Si substrates by pulsed laser deposition. The room-temperature structures and dielectric properties are studied by x-ray diffraction, scanning electron microscopy, and HP4294A impedance/phase analyzer. The temperature-dependent ferroelectric properties are systematically investigated by using a RT66A ferroelectric tester combined with a temperature-controllable vacuum chamber. For well-saturated hysteresis loops, with the temperature decrease from 295 to 97 K, the coercive field (Ec) and remanent polarization (Pr) increase and the saturated polarization (Ps) is almost temperature-independent. However, this is not the case for the unsaturated hysteresis loops. Temperature-dependent fatigue-resistance of the PLT25 films is also experimentally established: after 2.22 × 109 switching cycles, the nonvolatile polarizationdecreases 38% when measured at room-temperature and it decreases 15% at 97 K. The nature and population of point defects and their effects on the subtle variations of the Ec, Ps, Pr, and fatigue-resistance against temperature are discussed in detail.

Electrical Characteristics and Microstructures of Pr2O3-Doped Bi4Ti3O12 Thin Films

2014 ◽  
Vol 633 ◽  
pp. 370-373
Author(s):  
Chong Qing Huang ◽  
X.A. Mei ◽  
M. Chen ◽  
B. Li
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Single Phase ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Differential Resistance ◽  
Rf Magnetron Sputtering ◽  
Electrical Characteristics ◽  
Si Substrates ◽  
Ferroelectric Hysteresis

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.

Low-temperature ultraviolet sol-gel photoannealing processing of multifunctional lead-titanate-based thin films

2007 ◽  
Vol 22 (7) ◽  
pp. 1824-1833 ◽  
Author(s):  
M.L. Calzada ◽  
I. Bretos ◽  
R. Jiménez ◽  
H. Guillon ◽  
J. Ricote ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Processing ◽  
Lead Titanate ◽  
Remanent Polarization ◽  
Sol Gel ◽  
Rapid Thermal Processing ◽  
Hysteresis Loops ◽  
Relaxor Ferroelectric ◽  
Silicon Substrates ◽  
Ferroelectric Hysteresis

(Pb1−xCax)TiO3 perovskite thin films with nominal compositions of (Pb0.76Ca.24)TiO3 (ferroelectric) and (Pb0.50Ca0.50)TiO3 (relaxor-ferroelectric) were prepared on silicon substrates at low temperatures compatible with those used in Si-technology. The technique used for the processing of these films was ultraviolet (UV) sol-gel photoannealing, using photo-sensitive precursor solutions and UV-assisted rapid thermal processing. The UV-irradiation and thermal treatment of the solution-derived films (gel films) were carried out in air or in oxygen. In both cases, the formation of the perovskite occurred at the same temperature, and this temperature increased as the Ca2+ content increased. Thus, full-perovskite films of (Pb0.76Ca.24)TiO3 were obtained at 723 K whereas those of (Pb0.50Ca0.50)TiO3 were formed at 773 K. Well-defined ferroelectric hysteresis loops were measured in the (Pb0.76Ca.24)TiO3 films, with values of remanent polarization of Pr ∼ 11 μC cm−2 and coercive fields for the films processed in oxygen lower than those of the films processed in air, Ec ∼ 164 and ∼226 kV.cm−1, respectively. These films showed a ferro-paraelectric transition at close temperatures of Tmax ∼ 605 K, although with higher values of the permittivity for the film processed in oxygen, k ∼ 567 at 10 kHz. The (Pb0.50Ca.50)TiO3 films had a diffuse ferro-paraelectric transition with a relaxor-like character, also with higher k values for the films prepared in oxygen, k ∼ 179 at Tmax ∼ 20 K. The possible use of these materials in silicon integrated multifunctional devices is discussed in this paper.

scholarly journals Epitaxial Growth and Multiferroic Properties of (001)-Oriented BiFeO3-YMnO3 Films

2015 ◽  
Vol 2 (3-4) ◽  
pp. 157-162
Author(s):  
Peng-Xiao Nie ◽  
Yi-Ping Wang ◽  
Ying Yang ◽  
Guo-Liang Yuan ◽  
Wei Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Single Phase ◽  
Hysteresis Loops ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Leakage Currents ◽  
X Ray ◽  
Multiferroic Properties ◽  
Ferroelectric Hysteresis

Abstract In this paper, high-quality multiferroic (1-x)BiFeO3-xYMnO3 (x=0.05, 0.10, 0.15) thin films were successfully epitaxially grown on (001)SrTiO3 substrates with La0.67Sr0.33MnO3 buffered layers by pulsed laser deposition (PLD). X-ray diffraction shows the thin films are all single-phase perovskite with preferential orientation along the (001) direction. The (002) diffraction angles of thin films (from 0 to 0.15) shift to right, indicating the decrease of lattice parameters. All YMnO3-doped thin films exhibit strong upward self-poling via piezoelectric force microscope (PFM) measurement. Saturated ferroelectric hysteresis loops of thin films cannot be obtained even at the frequency of 50 kHz because of large leakage currents. It is noted that BFO-YMO thin films exhibit ferroelectricity considering the PFM and ferroelectric test. The magnetization measurements show that all BiFeO3-based films exhibit weak ferromagnetic behaviors with saturated magnetization at room temperature. The enhancement of magnetization was observed because of YMO doping, with the maximum saturation magnetization (M s) of 17.07 emu/cm3 in x=0.10 thin film.

Preparation and Properties of Barium Incorporated Strontium Bismuth Tantalate Ferroelectric Thin Films

1998 ◽  
Vol 541 ◽  
Author(s):  
Chung-Hsin Lu ◽  
Cheng-Yen Wen
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Barium Ions ◽  
X Ray ◽  
Diffraction Peaks ◽  
Metalorganic Decomposition ◽  
Strontium Ions

AbstractSrBi2Ta2O9thin films doped with barium ions were studied, in which Ba/(Sr+Ba) = 0.3 and 0.5, meanwhile the content of (Sr+Ba) remains unity to keep the stoichiometry of SrBi2Ta2O9. Films were deposited using metalorganic decomposition method with spin-on coating. Crystallinity, surface morphology, and ferroelectric properties of prepared thin films were investigated. From X-ray diffraction (XRD) analysis, barium ions substituted strontium ions in the SrBi2Ta2O9 lattice. Shift of diffraction peaks was observed, indicating a slight distortion of the lattice while barium ions incorporated into. The observation of prepared films indicated that the grain size of films annealed at 750 °C was about 0.7∼0.8 μm. Such barium incorporated SrBi2Ta2O9 thin films exhibited higher remanent polarization than the intrinsic SrBi2Ta2O9thin films.

scholarly journals INVESTIGATION ON STRUCTURAL AND FERROELECTRIC PROPERTIES OF Bi3.25La0.75Ti3O12 THIN FILMS

2018 ◽  
Vol 54 (1A) ◽  
pp. 80
Author(s):  
Tran Van Dung
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Solution Process ◽  
Hysteresis Loops ◽  
Sample Surface ◽  
Metal Electrode ◽  
Layered Perovskite ◽  
Oriented Growth

Lanthanum doped bismuth titanate (Bi3.25La0.75Ti3O12 abbreviated as BLT) has been known as one of typical materials for Bi-layered perovskite structure which possess several unique properties such as good fatigue with metal electrode and stable remanent polarization, hence it has potential applications in ferroelectric random access memory. In this work, the BLT thin films were fabricated on Pt/TiO2/SiO2/Si substrates by using a solution process, and then their features including crystal structure, surface morphology, and electrical properties were characterized by using X-ray diffraction system (XRD), scanning electron microscopy (SEM), and electrical measurement system (Radiant Precision LC 10), respectively. The obtained results point out that the BLT thin film annealed at 725 oC is mostly optimum from a viewpoint of film quality and ferroelectricity. In particular, the optimum BLT thin film having a thickness of 200 nm does not contain any cracks on the sample surface, and the grain size is closed to 400 nm from SEM observation. XRD patterns imply that the BLT thin film had stoichiometric structure with preferred orientations of (117) and (006), when annealed at temperatures higher than 725 oC. In addition, we found the influence of La (0.75) dopping on c-axis-oriented growth of BLT thin films is clear from the structural analysis. The remanent polarization of optimum BLT thin film is approximately 10 μC/cm2, but the ferroelectric hysteresis loops are not saturated at low applied voltages.

All Epitaxial Babi4Ti4O15 - LaNiO3 Heterostructures

1998 ◽  
Vol 541 ◽  
Author(s):  
K. M. Satyalakshmi ◽  
A. Pignolet ◽  
M. Alexe ◽  
N. D. Zakharov ◽  
C. Harnagea ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Ferroelectric Thin Film ◽  
Epitaxial Thin Films ◽  
Oxide Electrodes ◽  
Deposition Parameters ◽  
Ferroelectric Hysteresis ◽  
Ferroelectric Oxides

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.

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