Compositional Control of Ferroelectric Domain Structures in Eteroepitaxial PLZT Thin Films

1997 ◽  
Vol 493 ◽  
Author(s):  
K. S. Lee ◽  
Y. M. Kang ◽  
S. Baik
Keyword(s):  
Thin Films ◽  
Transformation Strain ◽  
Rf Magnetron Sputtering ◽  
Ferroelectric Domain ◽  
Ex Situ ◽  
Cubic Phase ◽  
Domain Formation ◽  
Axis Orientation ◽  
Domain Structures ◽  
Plzt Thin Films

ABSTRACTThe mechanism and control of ferroelectric domain formation in heteroepitaxial (Pb1−xLax)(ZryTi1-y)O3 (PLZT) thin films grown on MgO(001) substrates have been investigated as a function of composition and temperature. Pulsed laser deposition and RF magnetron sputtering techniques were used and optimized to fabricate epitaxial thin films with varying La and/or Zr concentrations. Periodic 9° domain structures were developed when the film transformed from the cubic phase to the tetragonal phase during cooling after deposition. As a result of the tetragonality of the films, the domain formation induced slightly tilted twin structures. All films were grown highly c axis oriented and the degree of c axis orientation was improved with increasing La or Zr concentration. Experimental observations of the 90° domain evolution in films have been carried out in-situ and ex-situ using conventional and synchrotron X-ray diffraction and demonstrated that the most important parameter affecting the domain structure and its abundance is the transformation strain at the Curie temperature, which can be varied systematically by changing the concentration of La and/or Zr in the PLZT system.

Comparison Between In-situ Annealing and External Annealing For Barium Ferrite Thin Films Made by RF Magnetron Sputtering

2005 ◽  
Vol 875 ◽  
Author(s):  
A. R. Abuzir ◽  
W. J. Yeh
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Saturation Magnetization ◽  
Barium Ferrite ◽  
Rf Magnetron Sputtering ◽  
Silicon Substrates ◽  
Axis Orientation ◽  
Average Value ◽  
Ferrite Thin Films

AbstractDue to their large magnetic anisotropy perpendicular to the film plane, barium ferrite thick films (BaFe12O19, or BaM) with c-axis orientation are attractive candidates for microwave applications [1,2]. Barium ferrite thin films on silicon substrates without under layer have been deposited under various conditions by RF magnetron sputtering. The structure of the as-grown films is amorphous. External annealing in air has been done at 950°C for ten minutes to crystallize the films. C-axis oriented thin films with squareness of about 0.87 and coercivity of about 3.8KOe are obtained.Thick BaM films with c-axis orientation are difficult to achieve with one single deposition. Multilayer technique looks promising to grow thick films [3]. The external annealing process is difficult to incorporate with the multilayer procedure. An in-situ annealing procedure has been developed to obtain films, which can be used as the basic component for future multilayer deposition. Barium ferrites are first magnetron sputtered on bare silicon substrates in Ar + O2 atmosphere at substrate temperature of 500-600°C, the deposition pressure was kept about 0.008 torr. After the deposition, the temperature of the substrate is immediately increased to about 860°C for ten minutes in 140 torr of argon (80%) and oxygen (20%) mixture of gas, which was introduced into the chamber without breaking the vacuum. With the in-situ process, c-axis oriented thin films of 0.88 squareness and coercivity value of about 4.3KOe are obtained.Both annealing methods seem to have the similar effect on the perpendicular squareness and coercivity at various film thicknesses. The average value of the saturation magnetization Ms obtained from the in-situ annealing using multilayer technique is higher than that of the external one. We have grown films up to 1.0 micron thickness using the multilayer technique, in which three layers of 0.3 μm thickness each are deposited until the final thickness is reached. After the deposition of each layer, it was in-situ annealed before starting the deposition of the next layer. With the multilayer technique, coercivity of about 3.5 KOe and average value of the saturation magnetization Ms of about 4.0 K Gauss is obtained.

Zinc Oxide Thin Films Grown on Nanostructured Al Thin Layer/Glass Substrate by RF Magnetron Sputtering

2011 ◽  
Vol 239-242 ◽  
pp. 777-780
Author(s):  
Ting Zhi Liu ◽  
Shu Wang Duo ◽  
C Y Hu ◽  
C B Li
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Magnetron Sputtering ◽  
Thin Layer ◽  
Glass Substrate ◽  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
Zno Film ◽  
Substrate Roughness ◽  
Axis Orientation

ZnO films were deposited on nanostructured Al (n-Al) /glass substrate by RF magnetron sputtering. The results shows that the relation (I (002) /I (100) ≈ I annealed (002)/I annealed (100) ≈1.1) shows the rough n-Al surface is suitable for the growth of a-axis orientation. Meanwhile, the influences of substrate roughness, crystallinity and (101) plane of ZnO film deposited on n-Al layer have been discussed. XPS implies more oxygen atoms are bound to Aluminum atoms, which result in the increase of high metallic Zn in the film.

Highly C-Axis Oriented Barium Titanate Ferroelectric Films Deposited on SrTiO3 Substrate Using an Off-Axis Sputtered Conductive Oxide Layer as Bottom Electrode

2011 ◽  
Vol 399-401 ◽  
pp. 926-929
Author(s):  
Wei Zhang ◽  
Mei Ling Yuan ◽  
Xian Yang Wang ◽  
Jun Ouyang
Keyword(s):  
Thin Films ◽  
Bottom Electrode ◽  
Rf Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Ferroelectric Films ◽  
Axis Orientation ◽  
X Ray ◽  
Pure Argon ◽  
Single Target ◽  
Conductive Oxide

BaTiO3(BTO) thin films were grown on (100) SrTiO3(STO) single crystal substrates using the RF-magnetron sputtering technique (RFMS) in both pure argon and mixed Ar/O2(20% O2) atmosphere. A La0.5Sr0.5CoO3(LSCO) layer was deposited as the bottom electrode by a 90° off-axis single-target RFMS. θ-2θ X-ray diffraction measurements showed that BTO thin films grown in both cases had a highly preferred c-axis orientation (001). From hysteresis measurements, it was confirmed that both films are ferroelectric. The ferroelectric polarizations 2Pr were 6.6 μC/cm2and 27.1 μC/cm2, for the BTO films grown in pure argon and in mixed Ar/O2atmosphere, respectively.

Computer simulation of ferroelectric domain structures in epitaxial BiFeO3 thin films

2008 ◽  
Vol 103 (9) ◽  
pp. 094111 ◽  
Author(s):  
J. X. Zhang ◽  
Y. L. Li ◽  
S. Choudhury ◽  
L. Q. Chen ◽  
Y. H. Chu ◽  
...  
Keyword(s):  
Thin Films ◽  
Computer Simulation ◽  
Ferroelectric Domain ◽  
Domain Structures ◽  
Bifeo3 Thin Films

Properties of Ba-Hexaferrite Thin Films with Different Layer Structures

2013 ◽  
Vol 774-776 ◽  
pp. 935-939
Author(s):  
Zhi Yong Xu ◽  
Zhong Wen Lan ◽  
Ke Sun ◽  
Zhong Yu ◽  
Rong Di Guo ◽  
...  
Keyword(s):  
Thin Films ◽  
Rf Magnetron Sputtering ◽  
Axis Orientation ◽  
Squareness Ratio ◽  
Nucleation Sites ◽  
Layer Structures ◽  
Out Of Plane ◽  
Crystallographic Characteristics ◽  
Film Substrate ◽  
Substrate Temperatures

M-type Ba-hexaferrite (BaM) thin films with two different structures (single layered and double layered) were deposited on (001) Al2O3 substrates by RF magnetron sputtering. The changes in microstructural and magnetic properties of the films corresponding to different layer structures and substrate temperatures (Ts) were investigated. Experimental results indicated that for the single layered films deposited directly on substrates at Ts = 300 °C and Ts = 500 °C, most of the grains are acicular type grains with their c-axis in-plane and/or randomly oriented. However, in the double layered film with first interfacial layer deposited at Ts = 300 °C and second layer deposited at Ts = 500 °C, good crystallographic characteristics and excellent perpendicular c-axis orientation were obtained. The c-axis dispersion angle (Δθc) decreased to 0.49°, while the squareness ratio and coercivity of the out-of-plane respectively increased to 0.85 and 4.67 kOe in the double layered film. The mechanism for improving perpendicular c-axis orientation with the interfacial BaM layer was attributed to an increase in the perpendicularly oriented nucleation sites and the release of the stress that comes from the film-substrate interface.

Basic Thin Film Process for Perovskite Ferroelectric Materials

1990 ◽  
Vol 200 ◽  
Author(s):  
Hideaki Adachi ◽  
Kiyotaka Wasa
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Rf Magnetron Sputtering ◽  
Ferroelectric Materials ◽  
Epitaxial Thin Films ◽  
Preparation Process ◽  
Film Preparation ◽  
Plzt Thin Film ◽  
Plzt Thin Films ◽  
Ferroelectric Perovskite

ABSTRACTThin film process for ferroelectric perovskite oxides has been investigated. Amorphous, polycrystal, and epitaxial thin films of Pb-based perovskite ferroelectrics were prepared by rf-magnetron sputtering, and their properties were discussed. Epitaxial PLZT thin films showed similar dielectric properties as PLZT bulk ceramics and also showed strong electrooptic effect. For further investigation, film preparation process was developed by multitarget sputtering and quaternary PLZT thin film with excellent epitaxial crystallinity was realized by using a graded composition layer.

Epitaxial cerium oxide buffer layers and YBa2Cu3O7−δ thin films for microwave device applications

1999 ◽  
Vol 14 (6) ◽  
pp. 2385-2393 ◽  
Author(s):  
Sissel N. Jacobsen ◽  
Lynnette D. Madsen ◽  
Ulf Helmersson
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Rf Magnetron Sputtering ◽  
Sample Surface ◽  
Columnar Structure ◽  
Buffer Layers ◽  
Ex Situ ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Appreciable Change

CeO2 films with thicknesses ranging from 8.8 to 199 nm were grown on Al2O3 (1102) (R-cut) substrates by off-axis rf magnetron sputtering. X-ray diffraction showed an epitaxial relationship with the CeO2 (001) planes parallel to the Al2O3 (1102) planes for all film thicknesses. Atomic force microscopy (AFM) revealed a rough surface morphology consisting of crystallites with lateral dimensions of 10–90 nm. In the thinnest film, these crystallites were regularly shaped and uniformly distributed on the substrate, while they were rectangularly shaped and oriented mainly in two directions, orthogonal to each other, in the thicker films. The surface roughness of the films increased with increasing layer thickness. Characterization of the microstructure was done by cross-sectional transmission electron microscopy (XTEM) and showed a polycrystalline, highly oriented, columnar structure with a top layer terminated by (111)-facets. High-quality YBa2Cu3O7−δ (YBCO) thin films were deposited directly onto the CeO2 layers. XTEM, rather surprisingly, showed a smooth interface between the YBCO and CeO2 layer. Postdeposition ex situ annealing was carried out on two CeO2 films and evaluated by AFM. Upon annealing samples at 930 °C, a relatively smooth morphology without facets was obtained. Annealing films at 800 °C caused no appreciable change in surface morphology, whereas igniting a YBCO plasma during a similar anneal clearly altered the sample surface, giving facets that were rounded.

Ferroelectric Domain Structures in Epitaxial PZT Thin Films: A Review

2002 ◽  
Vol 46 (1) ◽  
pp. 307-328 ◽  
Author(s):  
Kilho Lee ◽  
Kyeong Seok Lee ◽  
Yong Kwan Kim ◽  
Sunggi Baik
Keyword(s):  
Thin Films ◽  
Ferroelectric Domain ◽  
Pzt Thin Films ◽  
Domain Structures
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