Interfacial Structure of BaRuO3 Thin Films Grown On (111) SrTiO3

2000 ◽  
Vol 654 ◽  
Author(s):  
W. Tian ◽  
M. K. Lee ◽  
C. B. Eom ◽  
X. Q. Pan

AbstractBaRuO3 thin films were grown on (111) SrTiO3substrate by 90° off-axis rf-sputtering. Transmission electron microscopy studies revealed that the films consist of the metastable 4H hexagonal polymorph of BaRuO3 along with few defects. The films are c-axis oriented, single crystalline with the in-plane orientation relationship with respect to the SrTiO3substrate of [112 0] BaRuO3 // [110] SrTiO3. High-resolution transmission electron microscopy (HRTEM) studies of the film-substrate interface revealed the existence of a thin intermediate layer of the 9R hexagonal polymorph of BaRuO3 between the (111) SrTiO3 substrate and the 4H film. The formation mechanism for the intermediate layer is not fully understood though. Through the combination of HRTEM and quantitative image simulations, the atomic structure of the interface between the 9R intermediate layer and the underneath (111) SrTiO3 was constructed. Three initial growth modes were observed, each of them adopting the local continuity of the oxygen octahedral sublattice across the interface.

1995 ◽  
Vol 401 ◽  
Author(s):  
L. Ryen ◽  
E. Olssoni ◽  
L. D. Madsen ◽  
C. N. L. Johnson ◽  
X. Wang ◽  
...  

AbstractEpitaxial single layer (001) SrTiO3 films and an epitaxial Yba2Cu3O7-x/SrTiO3 multilayer were dc and rf sputtered on (110)rhombohedral LaAIO3 substrates. The microstructure of the films was characterised using transmission electron microscopy. The single layer SrTiO3 films exhibited different columnar morphologies. The column boundaries were due to the lattice mismatch between film and substrate. The boundaries were associated with interfacial dislocations at the film/substrate interface, where the dislocations relaxed the strain in the a, b plane. The columns consisted of individual subgrains. These subgrains were misoriented with respect to each other, with different in-plane orientations and different tilts of the (001) planes. The subgrain boundaries were antiphase or tilt boundaries.The individual layers of the Yba2Cu3O7-x/SrTiO3 multilayer were relatively uniform. A distortion of the SrTiO3 unit cell of 0.9% in the ‘001’ direction and a Sr/Ti ratio of 0.62±0.04 was observed, both in correspondence with the single layer SrTiO3 films. Areas with different tilt of the (001)-planes were also present, within each individual SrTiO3 layer.


1990 ◽  
Vol 5 (8) ◽  
pp. 1605-1611 ◽  
Author(s):  
S. J. Golden ◽  
H. Isotalo ◽  
M. Lanham ◽  
J. Mayer ◽  
F. F. Lange ◽  
...  

Superconducting YBaCuO thin films have been fabricated on single-crystal MgO by the spray-pyrolysis of nitrate precursors. The effects on the superconductive behavior of processing parameters such as time and temperature of heat treatment and film thickness were investigated. The superconductive behavior was found to be strongly dependent on film thickness. Films of thickness 1 μm were found to have a Tc of 67 K while thinner films showed appreciably degraded properties. Transmission electron microscopy studies have shown that the heat treatments necessary for the formation of the superconductive phase (for example, 950 °C for 30 min) also cause a substantial degree of film-substrate interdiffusion. Diffusion distances for Cu in the MgO substrate and Mg in the film were found to be sufficient to explain the degradation of the superconductive behavior in films of thickness 0.5 μm and 0.2 μm. From the concentration profiles obtained by EDS analysis diffusion coefficients at 950 °C for Mg into the YBaCuO thin film and for Cu into the MgO substrate were evaluated as 3 × 10−19 m2/s and 1 × 10−17 m2/s, respectively.


1996 ◽  
Vol 11 (11) ◽  
pp. 2777-2784 ◽  
Author(s):  
S. Takeno ◽  
S. Nakamura ◽  
K. Abe ◽  
S. Komatsu

A novel mosaic-like structure in SrTiO3 thin films was discovered and characterized by means of transmission electron microscopy (TEM). The films were deposited on a (001) oriented Pt surface. The orientation relationship between SrTiO3 film and Pt substrate was determined, and four types of growth modes were revealed. These four growth modes formed four types of domains, respectively, and these domains and Pt formed peculiarly ordered interfacial structures, i.e., near coincidence site lattices. Antiphase boundaries between two adjacent domains were also observed by high-resolution imaging.


2007 ◽  
Vol 14 (04) ◽  
pp. 751-754
Author(s):  
J. GAO ◽  
E. G. FU ◽  
Z. LUO ◽  
Z. WANG ◽  
D. P. YU

The microstructures in the YBa 2 Cu 3 O y films grown on Eu 2 CuO 4/ Y-ZrO 2(YSZ) buffered silicon were studied by means of transmission electron microscopy. Our effort was emphasized on the influence of the interfacial microstructures on the formation and epitaxy of the grown layer. It was found that a native Si -oxide layer ~ 5 nm was formed at the boundary between YSZ and silicon. Such an intermediate layer should be formed after the initial formation of the grown YSZ layer as the epitaxy of YSZ still remain. The epitaxy can be kept through all layers without the formation of big grain boundaries. No amorphous layers and secondary phases were observed at the interfaces of YSZ/ECO and YBCO/ECO. The results demonstrate that the crystallinity and the epitaxy of YBCO have been greatly improved by the bi-layer buffer.


2001 ◽  
Vol 673 ◽  
Author(s):  
G. Dehm ◽  
B.J. Inkson ◽  
T.J. Balk ◽  
T. Wagner ◽  
E. Arzt

ABSTRACTIn-situ transmission electron microscopy studies of metal thin films on substrates indicate that dislocation motion is influenced by the structure of the film/substrate interface. For Cu films grown on silicon substrates coated with an amorphous SiNx diffusion barrier, the transmission electron microscopy studies reveal that dislocations are pulled towards the interface, where their contrast finally disappears. However, in epitaxial Al films deposited on single-crystalline α- Al2O3 substrates, threading dislocations advance through the layer and deposit dislocation segments adjacent to the interface. In this latter case, the interface is between two crystalline lattices. Stresses in epitaxial Al films and polycrystalline Cu films were determined by substrate- curvature measurements. It was found that, unlike the polycrystalline Cu films, the flow stresses in the epitaxial Al films are in agreement with a dislocation-based model.


2009 ◽  
Vol 1186 ◽  
Author(s):  
Alessio Morelli ◽  
Sriram Venkatesan ◽  
George Palasantzas ◽  
Bart J. Kooi ◽  
Jeff De Hosson

AbstractThe piezoelectric properties of PTO thin films grown by pulsed laser deposition are investigated with piezoresponse force microscopy and transmission electron microscopy. The as-grown films exhibit upward polarization, and inhomogeneous distribution of piezoelectric characteristics. The data obtained reveal imprint during piezoresponse force microscopy measurements, nonlinearity in the piezoelectric deformation, and limited retention loss. Moreover, transmission electron microscopy shows the presence of defects near the film/substrate interface, which can be associated with the variations of piezoelectric properties.


Author(s):  
L. Tang ◽  
G. Thomas ◽  
M. R. Khan ◽  
S. L. Duan

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.


Author(s):  
C. Ewins ◽  
J.R. Fryer

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.


Author(s):  
J. T. Sizemore ◽  
D. G. Schlom ◽  
Z. J. Chen ◽  
J. N. Eckstein ◽  
I. Bozovic ◽  
...  

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).


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