Anisotropy in Epitaxial Fe3O4 and NiFe2O4 Thin Films

1994 ◽  
Vol 341 ◽  
Author(s):  
D. T. Margulies ◽  
F. T. Parker ◽  
F. E. Spada ◽  
A. E. Berkowitz
Keyword(s):  
Tensile Stress ◽  
Epitaxial Films ◽  
X Ray Diffraction ◽  
Bulk Properties ◽  
X Ray ◽  
Moment Distribution ◽  
Random Moment ◽  
Dc Magnetron Reactive Sputtering ◽  
Bulk Parameters ◽  
Applied Fields

AbstractFe3O4 and NiFe2O4 films were deposited on <100> and <110> MgO substrates by dc magnetron reactive sputtering. X-ray diffraction studies indicate epitaxial films under an inplane tensile stress. Magnetization studies show that the moments of the films are unsaturated in 70 kOe applied fields and they approach bulk values only in extrapolation. Conversion electron Mössbauer spectroscopy (CEMS) studies indicate bulk parameters for the Fe3O4 films, but show deviations from bulk properties for NiFe2O4 films. CEMS studies further indicate a random moment distribution for all films which is an unexpected property. In-plane torque curves are discussed in terms of single crystal behavior. The effect of the inplane tensile stress is also indicated in the torque curves.

Influence of LaNiO3 as an Electrode on the Properties of Ferroelectric Oxides

2000 ◽  
Vol 623 ◽  
Author(s):  
R. Kalare ◽  
M. Vedawyas ◽  
A. Kumar
Keyword(s):  
Ferroelectric Properties ◽  
Ferroelectric Thin Film ◽  
Memory Device ◽  
Epitaxial Films ◽  
Laser Deposition ◽  
Oxide Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Potential Electrode ◽  
Ferroelectric Oxides

AbstractAn electrode plays an important role in realising a ferroelectric thin film as a potential memory device. We have investigated LaNiO3 (LNO) as a potential electrode material and evaluated the ferroelectric properties of oxide materials like strontium bismuth tantalate (SBT) and barium titanate(BT). We have successfully deposited epitaxial films of LNO on Pt coated Si(100) and LaAlO3 (LAO) substrates using the pulsed excimer laser deposition technique. We are able to grow high quality SBT and BT films on top of this LNO layer. The X-ray diffraction revealed the epitaxy of the LNO, SBT and BT films. The ferroelectric properties of SBTand BT were investigated using the RT66A ferroelectric tester.

scholarly journals ScAlMgO4: an Oxide Substrate for GaN Epitaxy

1996 ◽  
Vol 1 ◽  
Author(s):  
E. S. Hellman ◽  
C. D. Brandle ◽  
L. F. Schneemeyer ◽  
D. Wiesmann ◽  
I. Brener ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Nitrogen Plasma ◽  
Epitaxial Films ◽  
Czochralski Growth ◽  
Congruent Melting ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Oxide Substrate ◽  
Deposition Conditions

We report the use of ScAlMgO4 as a substrate for the epitaxial growth of wurzitic GaN. The low misfit (+1.8%) allows coherent epitaxy of GaN, as observed by RHEED. The congruent melting of ScAlMgO4 makes Czochralski growth possible, suggesting that large, high quality substrates can be realized. Boules about 17mm in diameter are reported. We have used nitrogen-plasma molecular beam epitaxy to grow GaN epitaxial films onto ScAlMgO4 substrates. Band-gap photoluminescence has been observed from some of these films, depending primarily on the deposition conditions. A 3×3 superstructure has been observed by RHEED on the GaN surfaces. Structural analysis by x-ray diffraction indicates very good in-plane alignment of the GaN films. We also report thermal expansion measurements for ScAlMgO4.

X-Ray Diffraction Determination of the Effect of Passivations on Stress in Patterned Lines of Tungsten

1994 ◽  
Vol 338 ◽  
Author(s):  
L. Maniguet ◽  
M. Ignat ◽  
M. Dupeux ◽  
J.J. Bacmann ◽  
Ph. Normandon
Keyword(s):  
Tensile Stress ◽  
Line Width ◽  
Intrinsic Stress ◽  
X Ray Diffraction ◽  
Metal Line ◽  
X Ray ◽  
The Third ◽  
Diffraction Determination ◽  
Strain Tensors

ABSTRACTThe determination by X-ray diffraction of the elastic strain tensors and the corresponding stress tensors in patterned lines of tungsten has been performed to investigate the effect of various passivation. For unpassivated lines, the stresses are biaxial and decrease with decreasing line width. Passivation over patterned lines results in triaxial tensile stress. The stress along the line is not changed by the passivation. The stress across the line decreases as the line width decreases. The third component of stress, perpendicular to the surface, which appears with the passivation, increases with decreasing line width. High compressive intrinsic stress in the passivation does not result in high tensile stress in the metal line.

Growth of Epitaxial a-Axis and c-Axis Oriented Sr2RuO4 Films

1995 ◽  
Vol 401 ◽  
Author(s):  
S. Madhavan ◽  
B. J. Gibbons ◽  
A. Dabkowski ◽  
H. A. Dabkowska ◽  
S. Trolier-Mckinstry ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Epitaxial Films ◽  
Temperature Measurements ◽  
Laser Deposition ◽  
Metallic Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oriented Films

AbstractEpitaxial films of Sr2RuO4 have been grown in situ by pulsed laser deposition on (100) LaAlO3 and (100) LaSrGaO4 substrates. X-ray diffraction results show that the films are single domain and grow c-axis oriented on (100) LaAlO3 and a-axis oriented on (100) LaSrGaO4 substrates. X-ray ø-scans indicate epitaxial alignment of the film and substrate in-plane axes in both cases. Resistivity versus temperature measurements reveal that the as-grown c-axis oriented films are semiconducting and the a-axis oriented films are metallic. The metallic films grown so far were found to be non-superconducting down to 50 mK.

Chemical Strain Kinetics Induced by Oxygen Surface Exchange in Epitaxial Films Explored by Time-Resolved X-ray Diffraction

2013 ◽  
Vol 25 (18) ◽  
pp. 3640-3647 ◽  
Author(s):  
Roberto Moreno ◽  
Pablo García ◽  
James Zapata ◽  
Jaume Roqueta ◽  
Julienne Chaigneau ◽  
...  
Keyword(s):  
Epitaxial Films ◽  
X Ray Diffraction ◽  
Surface Exchange ◽  
Time Resolved ◽  
X Ray ◽  
Oxygen Surface Exchange ◽  
Oxygen Surface ◽  
Chemical Strain

Stresses in Passivated Films

1990 ◽  
Vol 188 ◽  
Author(s):  
Paul A. Flinn
Keyword(s):  
Tensile Stress ◽  
Accurate Determination ◽  
Silicon Oxynitride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Curvature Measurement ◽  
Formation Of Cracks ◽  
Patterned Films ◽  
Strain Tensors

ABSTRACTAlthough wafer curvature measurement provides a rapid and accurate determination of stress in a uniform thin film, the technique is not applicable to patterned films. To study the stress in metal lines, and the effect of passivation on that stress, it is necessary to use X-ray diffraction. To obtain the sensitivity and precision required, a generalized focusing diffractometer (GFD), that had been developed especially for work on thin films, was used in this study.The elastic strain tensors for aluminum and aluminum-silicon films and patterned lines were determined by X-ray diffraction. The corresponding stress tensors were calculated with the use of the known elastic constants of aluminum. The effect of various oxide and oxynitride passivations was investigated. Passivation over uniform metal films has very little effect, while passivation over patterned metal results in substantial triaxial tensile stress in the metal. Contrary to the conventional wisdom, high compressive stress in the passivation does not result in additional tensile stress in the metal. A possible explanation for the frequently observed deleterious effect (increased tendency for formation of cracks and voids) of highly compressive silicon nitride and silicon oxynitride passivations will be discussed.

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