Hydrostatic and Biaxial Strain in BaxSr1-xTiO3 Films Grown by Pulsed Laser Deposition

2000 ◽  
Vol 623 ◽  
Author(s):  
C. M. Carlson ◽  
P. A. Parilla ◽  
T. V. Rivkin ◽  
J. D. Perkins ◽  
D. S. Ginley
Keyword(s):  
Pulsed Laser Deposition ◽  
Residual Strain ◽  
Pulsed Laser ◽  
Lattice Parameters ◽  
Laser Deposition ◽  
Strain Component ◽  
Biaxial Strain ◽  
Rocking Curve ◽  
Out Of Plane ◽  
Bst Films

AbstractWe grew BaxSr1−xTiO3 (BST) films on MgO single crystal substrates by pulsed laser deposition (PLD). We report the in-plane (a) and out-of-plane (c) lattice parameters of BST films deposited in a range of O2 deposition pressures [P(02)], as measured by asymmetric rocking curve diffraction. As P(O2) increases, the films' biaxial strain changes from compression (a < c), to cubic (a = c), and then to tension (a > c). Furthermore, both a and c are larger than the lattice constant for bulk BST of the same composition. This indicates the presence of a hydrostatic strain component in addition to the biaxial component. From the measured lattice parameters, we calculate the total residual strain in terms of biaxial and hydrostatic components. We also examine the effects of a post-deposition anneal. Characterizing residual strain and understanding its origin(s) are important since strain affects the dielectric properties of BST films and thereby the properties of devices which incorporate them.

Structure-Property Relationships in W Doped (Ba,Sr)TiO3 Thin Films Deposited by Pulsed Laser Deposition on (001) MgO

2002 ◽  
Vol 720 ◽  
Author(s):  
N. Navi ◽  
J.S. Horwitz ◽  
H.-D. Wu ◽  
S.B. Qadri
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Lattice Parameters ◽  
Laser Deposition ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Deposition Pressure ◽  
Structure Property Relationships ◽  
Plane Lattice ◽  
Out Of Plane

AbstractBaxSr(1-x)TiO3 films (BST) with x=0.5, 0.6, 0.7, containing 1% W, were grown by pulsed laser deposition on MgO (001) substrates in an oxygen pressure from 3 to 500 mTorr, at a substrate temperature of 720 C. The crystal structure of the film, as determined from x-ray diffraction, was fit to a tetragonal distortion of a cubic lattice having two in-plane lattice parameters. The in and out-of-plane lattice parameters c, a, á, and lattice distortion (a/c and á/c) were calculated from the positions of the measured BST reflections ((004), (024) and (224)). The dielectric properties of the film at 2 GHz were measured using gap capacitors deposited on top of the dielectric film, at room temperature. For all compositions, as a function of the oxygen deposition pressure, a peak in the change in the dielectric constant, as a function of an applied electric field (0 – 80 kV/cm), was observed for films deposited in 50 mTorr of oxygen. Unlike the pure BST, the dielectric Q was insensitive to the oxygen deposition pressure. The largest Kfactor (K=(ε(0)-ε(V)/ε(0) x Q(0)) for films deposited from Ba0.6Sr0.4TiO3 target were observed in a film that had a minimum in-plane strain, where a~á.

Pulsed Laser Deposition of BaxSr1−xTiO3 Films on MgO, LaAlO3 and SrTiO3 for Tunable Microwave Applications

1998 ◽  
Vol 541 ◽  
Author(s):  
Wontae Chang ◽  
James S. Horwitz ◽  
Won-Jeong Kim ◽  
Jeffrey M. Pond ◽  
Steven W. Kirchoefer ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electric Field ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Dielectric Constants ◽  
Laser Deposition ◽  
Film Stress ◽  
Donor Acceptor ◽  
Bst Films

AbstractSingle phase BaxSr1−xTiO3 (BST) films (∼0.5-7 μm thick) have been deposited onto single crystal substrates (MgO, LaAlO3, SrTiO3) by pulsed laser deposition. Silver interdigitated electrodes were deposited on top of the ferroelectric film. The room temperature capacitance and dielectric Q (1/tanδ) of the film have been measured as a function of electric field (≤80 kV/cm) at 1 - 20 GHz. The dielectric properties of the film are observed to strongly depend on substrate type and post-deposition processing. After annealing (≤1000° C), it was observed that the dielectric constant and % tuning decreased and the dielectric Q increased for films deposited onto MgO, and the opposite effect was observed for films deposited onto LaA1O3. Presumably, this change in dielectric properties is due to the changes in film stress. Very thin (∼50 Å) amorphous BST films were successfully used as a stress-relief layer for the subsequently deposited crystalline BST (∼5000 Å) films to maximize % tuning and dielectric Q. Films have been deposited from stoichiometric targets and targets that have excess Ba and Sr. The additional Ba and Sr has been added to the target to compensate for deficiencies in Ba and Sr observed in the deposited BST (x=0.5) films. Films deposited from compensated targets have higher dielectric constants than films deposited from stoichiometric targets. Donor/acceptor dopants have also been added to the BST target (Mn, W, Fe ≤4 mol.%) to further improve the dielectric properties. The relationship between the dielectric constant, the dielectric Q, the change in dielectric constant with electric field is discussed.

CRYSTALLINE SrTiO3 THIN FILMS ON SILICON BY PULSED LASER DEPOSITION

2005 ◽  
Vol 19 (01n03) ◽  
pp. 533-535
Author(s):  
J. H. HAO ◽  
J. GAO
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Perovskite Oxide ◽  
Deposition Technique ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Silicon Materials

We have developed a process to grow SrTiO 3 ( STO ) thin films showing single (110) orientation directly on Si by means of pulsed laser deposition technique. The growth of STO films directly on Si has been described. The crystallinity of the grown STO films was characterized by X-ray diffraction analysis of θ-2θ scan and rocking curve. Our results may be of interest for better understanding of the growth based on the perovskite oxide thin films on silicon materials.

scholarly journals Lead potassium niobate thin films grown by Pulsed Laser Deposition

2016 ◽  
Vol vol1 (1) ◽  
Author(s):  
Billal Allouche ◽  
Yaovi Gagou ◽  
M. El Marssi
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Potassium Niobate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Deposition Parameters ◽  
Out Of Plane

By pulsed laser deposition, lead potassium niobate Pb2KNb5O15 was grown on (001) oriented Gd3Ga5O12 substrate using a platinum buffer layer. The PKN thin films were characterized by X-Ray diffraction and Scanning Electron Microscopy (SEM). The dependence of their structural properties as a function of the deposition parameters was studied. It has been found that the out of plane orientation of PKN film depends on the oxygen pressure used during the growth. Indeed, PKN thin film is oriented [001] for low pressure and is oriented [530] for high pressure. For these two orientations, the crystalline quality of PKN film was determined using omega scans.

Epitaxy of PbTio3 on (100) SrTio3 and Vicinal (100) SrTio3 by Pulsed Laser Deposition

1995 ◽  
Vol 401 ◽  
Author(s):  
C. D. Theis ◽  
D. G. Schlom
Keyword(s):  
Diffraction Analysis ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Miscut Substrate

AbstractEpitaxial PbTiO3 films have been grown on (100) SrTiO3 substrates by pulsed laser deposition. X-ray diffraction analysis indicates pure c-axis oriented PbTiO3 films with a rocking curve FWHM of 0.25° for the 002 reflection. Thicker films (˜ 2000 Å) grown on 4° miscut SrTiO3 show mixed aaxis and c-axis PbTiO3 due to twinning along {1011} planes. The [100] axis of the a-axis domains are misoriented by 3.4° - 3.8° toward <001> substrate directions with respect to the substrate normal. In contrast to growth on well-oriented (100) SrTiO3 surfaces where the four equivalent tilts of the [100] axis of the a-axis domains are equally likely, on vicinal SrTiO3 the a-axis domains are preferentially oriented (˜ 90 vol. %) in an uphill direction with respect to the miscut substrate.

Epitaxial Growth of GaN Thin Films Using a Hybrid Pulsed Laser Deposition System

1999 ◽  
Vol 572 ◽  
Author(s):  
Philippe Mérel ◽  
Mohamed Chaker ◽  
Henri Pépin ◽  
Malek Tabbal
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Epitaxial Growth ◽  
Laser Intensity ◽  
Pulsed Laser ◽  
Growth Conditions ◽  
Laser Deposition ◽  
Nitrogen Flux ◽  
High Quality ◽  
Rocking Curve

ABSTRACTA hybrid Pulsed Laser Deposition system was developed to perform epitaxial growth of GaN on sapphire(0001). This system combines the laser ablation of a cooled Ga target with a well-characterized atomic nitrogen source. Taking advantage of the flexibility of this unique deposition system, high quality GaN thin films were deposited by optimizing both the laser intensity and the nitrogen flux. To date, our best GaN films show a FWHM of the GaN(0002) rocking curve peak equal to 480 arcsec. This result has been obtained at a laser intensity of I = 7×107 W/cm2, a substrate temperature of 800°C and under Ga-rich growth conditions.

Pulsed Laser Deposition of Highly Crystalline Gan Films on Sapphire

1997 ◽  
Vol 482 ◽  
Author(s):  
R. D. Vispute ◽  
V. Talyansky ◽  
S. Chupoon ◽  
R. Enck ◽  
T. Dahmas ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Target Surface ◽  
Surface Region ◽  
Laser Deposition ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
Ion Channeling ◽  
High Degree

AbstractWe report high quality epitaxial growth of GaN film by pulsed laser deposition technique. In this method, a KrF pulsed excimer laser was used for ablation of a polycrystalline, stoichiometric GaN target. The ablated material was deposited on a substrate kept at a distance of ∼ 7 cm from the target surface and in an NH3 background pressure of 10−5 Torr and temperature of 750°C. The films (∼0.5 μm thick) grown on AIN buffered sapphire showed a x-ray diffraction rocking curve FWHM of 4–6 arc minutes. The ion channeling minimum yield in the surface region was ∼3% indicating a high degree of crystallinity. The optical band gap was found to be 3.4 eV. The epitaxial films were shiny, and the surface RMS roughness was ∼ 5–15 nm. The electrical resistivity of these films was in the range of 10−2–102 Ω-cm with a mobility in excess of 60 cm2V-1s−1 and carrier concentration of 1017–1019cm−3.

scholarly journals Accidental Impurities in Epitaxial Pb(Zr0.2Ti0.8)O3 Thin Films Grown by Pulsed Laser Deposition and Their Impact on the Macroscopic Electric Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1177
Author(s):  
Georgia Andra Boni ◽  
Cristina Florentina Chirila ◽  
Viorica Stancu ◽  
Luminita Amarande ◽  
Iuliana Pasuk ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
The Other ◽  
Laser Deposition ◽  
Composition Analysis ◽  
Structural And Electrical Properties ◽  
Out Of Plane ◽  
Plasma Mass Spectrometry ◽  
A Domains ◽  
Pure Target

Structural and electrical properties of epitaxial Pb(Zr0.2Ti0.8)O3 films grown by pulsed laser deposition from targets with different purities are investigated in this study. One target was produced in-house by using high purity precursor oxides (at least 99.99%), and the other target was a commercial product (99.9% purity). It was found that the out-of-plane lattice constant is about 0.15% larger and the a domains amount is lower for the film grown from the commercial target. The polarization value is slightly lower, the dielectric constant is larger, and the height of the potential barrier at the electrode interfaces is larger for the film deposited from the pure target. The differences are attributed to the accidental impurities, with a larger amount in the commercial target as revealed by composition analysis using inductive coupling plasma-mass spectrometry. The heterovalent impurities can act as donors or acceptors, modifying the electronic characteristics. Thus, mastering impurities is a prerequisite for obtaining reliable and reproducible properties and advancing towards all ferroelectric devices.

Pulsed Laser Deposition of BaxSr1-xTiO3 Thin Films for Frequency Agile Microwave Electronics

1998 ◽  
Vol 526 ◽  
Author(s):  
W. Chang ◽  
J. S. Horwitz ◽  
J. M. Pond ◽  
S. W. Kirchoefer ◽  
D B. Chrisey
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Lattice Mismatch ◽  
Pulsed Laser ◽  
Dielectric Behavior ◽  
Laser Deposition ◽  
Film Stress ◽  
Bst Films ◽  
The Difference ◽  
Film Substrate

AbstractOriented, single phase thin films (~5000Å thick) of BaxSr1-xTiO3 (BST) have been deposited on to (100) MgO and LaAlO3 (LAO) single crystal substrates using pulsed laser deposition (PLD). A strong correlation is observed between the microstructure of the deposited film and the dielectric tuning and loss at microwave frequencies. Microstructural defects observed in as deposited films include strain, due to film substrate lattice mismatch and oxygen and cation vacancies. Compensation of the ablation target with excess Ba and Sr is observed to increase the dielectric constant and to reduce the dielectric loss. Post-deposition, bomb annealing of films at high temperatures (1250°C) is observed to fill oxygen vacancies and increase grain size. The difference in the dielectric behavior for as-deposited and low temperature annealed BST films on MgO and BST films on LAO is observed and may be attributed to the differences in film stress. A further improvement in the dielectric behavior is observed by the addition of donor/acceptor dopants such as Mn. The data shows that ferroelectric thin films can be used to build tunable microwave circuits that offer significant performance advantages over devices made from conventional semiconducting materials.

scholarly journals Structure and Magnetization of Strontium Hexaferrite (SrFe12O19) Films Prepared by Pulsed Laser Deposition

2021 ◽  
Vol 8 ◽  
Author(s):  
M. Khojaste khoo ◽  
P. Kameli
Keyword(s):  
Pulsed Laser Deposition ◽  
Quantum Interference ◽  
Pulsed Laser ◽  
Hysteresis Loops ◽  
Laser Deposition ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
Oriented Growth ◽  
X Ray ◽  
Out Of Plane

M-type strontium hexaferrite (SrM) thin films show excellent magnetic properties and uniaxial magnetic anisotropy. We systematically investigated the magnetism of SrM films prepared by pulsed-laser deposition on different substrates [Al2O3 (11¯02), SrTiO3 (100), ZnO (0001), and LiNbO3 (0001)] at vacuum (10−4 Pa) and a substrate temperature of 800°C. Prepared films were annealed in air at a temperature of 1,000°C for 2 hours. This investigation determined the effect of annealing and different substrates on the morphology, strain, and hysteresis loops of the films. The prepared films were characterized using x-ray diffractometry, Raman spectroscopy, scanning electron microscopy, and superconducting quantum interference device (SQUID) magnetometry. X-ray diffraction analyses confirmed c-oriented growth along the out-of-plane direction in most films. We found that annealing causes enhanced crystallization in films and a significant increase in coercivity. The highest coercivity of ∼11 KOe was measured for the film deposited on the Al2O3 (11¯02) substrate.

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