Grain orientations and grain boundary networks of YBa2Cu3O7−δ films deposited by metalorganic and pulsed laser deposition on biaxially textured Ni–W substrates

2006 ◽  
Vol 21 (4) ◽  
pp. 923-934 ◽  
Author(s):  
D.M. Feldmann ◽  
T.G. Holesinger ◽  
C. Cantoni ◽  
R. Feenstra ◽  
N.A. Nelson ◽  
...  

We report a detailed study of the grain orientations and grain boundary (GB) networks in YBa2Cu3O7-δ (YBCO) films ∼0.8 μm thick grown by both the in situ pulsed laser deposition (PLD) process and the ex situ metalorganic deposition (MOD) process on rolling-assisted biaxially textured substrates (RABiTS). The PLD and MOD growth processes result in columnar and laminar YBCO grain structures, respectively. In the MOD-processed sample [full-width critical current density Jc(0 T, 77 K) = 3.4 MA/cm2], electron back-scatter diffraction (EBSD) revealed an improvement in both the in-plane and out-of-plane alignment of the YBCO relative to the template that resulted in a significant reduction of the total grain boundary misorientation angles. A YBCO grain structure observed above individual template grains was strongly correlated to larger out-of-plane tilts of the template grains. YBCO GBs meandered extensively about their corresponding template GBs and through the thickness of the film. In contrast, the PLD-processed film [full width Jc(0 T, 77 K) = 0.9 MA/cm2] exhibited nearly perfect epitaxy, replicating the template grain orientations. No GB meandering was observed in the PLD-processed film with EBSD. Direct transport measurement of the intra-grain Jc(0 T, 77 K) values of PLD and MOD-processed films on RABiTS revealed values up to 4.5 and 5.1 MA/cm2, respectively. As the intra-grain Jc values were similar, the significantly higher full-width Jc for the MOD-processed sample is believed to be due to the improved grain alignment and extensive GB meandering.

2000 ◽  
Vol 15 (12) ◽  
pp. 2647-2652 ◽  
Author(s):  
M. Paranthaman ◽  
C. Park ◽  
X. Cui ◽  
A. Goyal ◽  
D. F. Lee ◽  
...  

Short segments of YBa2Cu3O7-y (YBCO) coated conductors were fabricated on rolling-assisted biaxially textured substrates (RABiTS) with a layer sequence of CeO2/YSZ/Ni using an ex situ BaF2 precursor process. Pulsed laser deposition (PLD) was used to deposit both YSZ and CeO2 layers. The YBCO films were grown using e-beam coevaporated Y–BaF2–Cu precursors followed by postannealing. An overall engineering current density, JE, of 28,000 A/cm2 and critical current, Ic, of 147 A/cm width at 77 K were achieved for a 1.6-μm-thick YBCO film. This result demonstrates the possibility of using both the ex situ BaF2 precursor approach and the RABiTS process for producing long lengths of high-JE coated conductors.


2010 ◽  
Vol 123-125 ◽  
pp. 375-378 ◽  
Author(s):  
Ram Prakash ◽  
Shalendra Kumar ◽  
Chan Gyu Lee ◽  
S.K. Sharma ◽  
Marcelo Knobel ◽  
...  

Ce1-xFexO2 (x=0, 0.01, 0.03 and 0.0 5) thin films were grown by pulsed laser deposition technique on Si and LaAlO3 (LAO) substrates. These films were deposited in vacuum and 200 mTorr oxygen partial pressure for both the substrates. These films were characterized by x-ray diffraction XRD and Raman spectroscopy measurements. XRD results reveal that these films are single phase. Raman results show F2g mode at ~466 cm-1 and defect peak at 489 cm-1 for film that deposited on LAO substrates, full width at half maximum (FWHM) is increasing with Fe doping for films deposited on both the substrates.


2005 ◽  
Vol 902 ◽  
Author(s):  
YauYau Tse ◽  
P. S. Suherman ◽  
T. J. Jackson ◽  
I. P. Jones

AbstractBa0.5Sr0.5TiO3 (BSTO) thin films were grown on (001) MgO using pulsed-laser deposition (PLD). The microstructures of in-situ and ex-situ annealed BSTO films were studied by X-ray diffraction and transmission electron microscopy (TEM). The films showed a cube on cube epitaxial relationship with <100> BSTO // <100> MgO. They were essentially single crystals with a columnar structure and possessed smooth surfaces. The interfaces of the BSTO films and substrates were atomically sharp, with misfit dislocations. Better crystallinity and full strain relaxation was obtained in films grown in 10-1 mbar oxygen and annealed ex-situ. A 30% increase in dielectric tuneability was achieved compared with in-situ annealing and deposition at 10-4 mbar. Threading dislocations are the dominant defects in the films grown in 10-1 mbar oxygen and annealed ex-situ, while the films with in-situ annealing show columnar structures with low angle boundaries.


2005 ◽  
Vol 12 (04) ◽  
pp. 539-543 ◽  
Author(s):  
QUANHE BAO ◽  
CHUANZHONG CHEN ◽  
LUBIN CHEN ◽  
DIANGANG WANG ◽  
TINGQUAN LEI ◽  
...  

A modified surface layer of hydroxyapatite (HA) target was observed before and after pulsed laser deposition. Two types of HA targets were used for laser ablation. We observed that the surface morphology of the target has a very fine compacted grain structure and presents many irregularities with some microroughness and microporosity before laser ablation. The laser ablated regions can be divided into two areas: one area is porous and rough but the other is dense and smooth. The percentage of particles in the films was high for the films produced with targets that were sintered at 1200°C.


2016 ◽  
Vol vol1 (1) ◽  
Author(s):  
Billal Allouche ◽  
Yaovi Gagou ◽  
M. El Marssi

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.


2002 ◽  
Vol 744 ◽  
Author(s):  
P. Bhattacharya ◽  
Rasmi R. Das ◽  
Ram S. Katiyar

ABSTRACTWide bandgap (∼6 eV) ZnO/MgO multilayer thin films have been fabricated using pulsed laser deposition technique from their respective targets on c-plane Al2O3 substrates. The thickness of single ZnO sublayer thickness was varied in the range of 0.75–2.5 nm with a fixed MgO sublayer thickness of 1 nm in order to achieve a total film thickness of ∼300 nm. The structural transition from hexagonal to cubic phase was observed with the decrease in the thickness of single ZnO layer from 2.5 to 0.75 nm that resulted in the increase in bandgap from 3.5 to 6.2 eV. Mg contents of the films were increased from 40 % to 60 % for hexagonal and cubic phases, respectively. The surface roughness and grain structure were not influenced much with the increase of Mg concentration. Resistivity of the films was increased six orders of magnitude with the increase in Mg incorporation. The post annealing at 750° C did not show any significant change in the crystal structure and the optical properties.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1177
Author(s):  
Georgia Andra Boni ◽  
Cristina Florentina Chirila ◽  
Viorica Stancu ◽  
Luminita Amarande ◽  
Iuliana Pasuk ◽  
...  

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.


2021 ◽  
Vol 8 ◽  
Author(s):  
M. Khojaste khoo ◽  
P. Kameli

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.


Author(s):  
James E. McCrone ◽  
Gary Gibson ◽  
Jeffrey L. Tallon ◽  
John R. Cooper ◽  
Zoe Barber

1997 ◽  
Vol 12 (5) ◽  
pp. 1297-1305 ◽  
Author(s):  
C. D. Theis ◽  
D. G. Schlom

Epitaxial PbTiO3 films have been grown on vicinal (001) SrTiO3 substrates by pulsed laser deposition. Vicinal SrTiO3 substrates with misorientations up to 9° from (001) were used, and the influence of the direction of misorientation on the resulting domain structure was studied. 4-circle x-ray diffraction analysis indicates that thin (40 nm) PbTiO3 films are completely c-axis oriented [rocking curve full-width-at-half-maximum (FWHM) of 0.25° for the 002 reflection] and that thicker films (∼ 200 nm) contain mixed a-axis and c-axis PbTiO3 domains due to twinning along {011} planes. The [100] axis of the a-axis domains is misoriented by 2.1° to 3.3° toward 〈100〉 substrate directions with respect to the substrate normal. In contrast to growth on well-oriented (001) 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 in an uphill direction with respect to the crystallographic miscut.


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