Giant Magnetoresistance and Structure of Phase-Segregated Epitaxial Metals

1993 ◽  
Vol 313 ◽  
Author(s):  
R.F. Marks ◽  
R.F.C. Farrow ◽  
G.R. Harp ◽  
S.S.P. Parkin ◽  
T.A. Rabedeau ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Grazing Incidence ◽  
Film Structure ◽  
X Ray ◽  
Spacing Effects ◽  
X Ray Scattering ◽  
Technological Potential ◽  
First Time

ABSTRACTGiant Magnetoresistance, GMR, in thin metal films elicits attention due to its technological potential as well as its relevance to theory of exchange coupling. Epitaxial, phase-segregated ferromagnet/paramagnet Mixtures have been grown by UHV evaporation. Such films show spontaneous formation of ferromagnetic clusters, leading to large values of GMR (40% at room temperature) as grown. The growth of Co-Cu, Co-Ag, Fe-Ag and Permalloy-Ag films are described. Structural analysis by grazing-incidence small angle X-ray scattering (GISAXS) provides a measure of cluster size and characteristic spacing. Effects of growth temperature and subsequent annealing on GMR and film structure are described. Preliminary results of TEM examination of (001) Fe-Ag and Co-Ag granular films are presented for the first time.

Determination of Strain Distributions in Aluminum Thin Films as a Function of Temperature by the use of Synchrotron Grazing Incidence X-Ray Scattering

1991 ◽  
Vol 239 ◽  
Author(s):  
Ramnath Venkatraman ◽  
Paul R. Besser ◽  
Sean Brennan ◽  
John C. Bravman
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Grazing Incidence ◽  
Surface Relaxation ◽  
Line Broadening ◽  
X Ray ◽  
Relaxation Effects ◽  
X Ray Scattering ◽  
Ray Scattering

ABSTRACTWe have measured elastic strain distributions with depth as a function of temperature in Al thin films of various thicknesses on oxidized silicon using synchrotron grazing incidence X-ray scattering (GIXS). Disregarding minor surface relaxation effects that depend on the film thickness, it is shown that there are no gross strain gradients in these films in the range of temperatures (between room temperature and 400°C) considered. We also observe X-ray line broadening effects, suggesting an accumulation of dislocations on cooling the films, and their annealing out as the films are reheated.

Cyclic topology effects on the morphology of biocompatible and environment-friendly poly(ε-caprolactone) under nanoscale film confinement

2020 ◽  
Vol 11 (28) ◽  
pp. 4630-4638 ◽  
Author(s):  
Li Xiang ◽  
Wonyeong Ryu ◽  
Jehan Kim ◽  
Moonhor Ree
Keyword(s):  
Synchrotron Radiation ◽  
Grazing Incidence ◽  
Film Morphology ◽  
Environment Friendly ◽  
X Ray ◽  
X Ray Scattering ◽  
Radiation Sources ◽  
First Time ◽  
Ray Scattering

Quantitative grazing incidence X-ray scattering analysis combined with X-ray reflectivity using synchrotron radiation sources was explored for the first time cyclic topology effects on the nanoscale film morphology of poly(ε-caprolactone).

scholarly journals Thermal unequilibrium of strained black CsPbI3 thin films

Science ◽  
2019 ◽  
Vol 365 (6454) ◽  
pp. 679-684 ◽  
Author(s):  
Julian A. Steele ◽  
Handong Jin ◽  
Iurii Dovgaliuk ◽  
Robert F. Berger ◽  
Tom Braeckevelt ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Optoelectronic Devices ◽  
Grazing Incidence ◽  
Optically Active ◽  
Wide Angle ◽  
Biaxial Strain ◽  
X Ray ◽  
X Ray Scattering ◽  
Thermal Stability Of

The high-temperature, all-inorganic CsPbI3 perovskite black phase is metastable relative to its yellow, nonperovskite phase at room temperature. Because only the black phase is optically active, this represents an impediment for the use of CsPbI3 in optoelectronic devices. We report the use of substrate clamping and biaxial strain to render black-phase CsPbI3 thin films stable at room temperature. We used synchrotron-based, grazing incidence, wide-angle x-ray scattering to track the introduction of crystal distortions and strain-driven texture formation within black CsPbI3 thin films when they were cooled after annealing at 330°C. The thermal stability of black CsPbI3 thin films is vastly improved by the strained interface, a response verified by ab initio thermodynamic modeling.

Stress in Copper Thin Films with Barrier Layers

1993 ◽  
Vol 308 ◽  
Author(s):  
Richard P. Vinci ◽  
John C. Bravman
Keyword(s):  
Thermal Cycle ◽  
Inverse Relationship ◽  
Room Temperature ◽  
Grazing Incidence ◽  
Dislocation Motion ◽  
X Ray ◽  
Cu Films ◽  
Barrier Layers ◽  
Dc Sputtering ◽  
X Ray Scattering

ABSTRACTWafer curvature and grazing incidence x-ray scattering (GIXS) techniques were used to investigate the biaxial stresses induced in blanket Cu films during a thermal cycle to 460°C and back to room temperature. Cu was deposited by DC sputtering at ambient temperature. Several different barrier layer materials — SiO2, W, Ta, TiN, and Si3N4 — were used to compare any effect barrier choice might have on Cu microstructure evolution and mechanical behavior. Ta and Si3N4 encouraged a strong (111) Cu texture. A W barrier led to an untextured microstructure which underwent large, uneven grain growth during thermal cycling. Several samples were capped with a Ta layer which affected the stress behavior during cooling by inhibiting dislocation motion. An inverse relationship between strength and thickness was also documented.

scholarly journals Convolutional neural networks for grazing incidence x-ray scattering patterns: thin film structure identification

2019 ◽  
Vol 9 (02) ◽  
pp. 586-592 ◽  
Author(s):  
Shuai Liu ◽  
Charles N. Melton ◽  
Singanallur Venkatakrishnan ◽  
Ronald J. Pandolfi ◽  
Guillaume Freychet ◽  
...  
Keyword(s):  
Thin Film ◽  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Grazing Incidence ◽  
Film Structure ◽  
Structure Identification ◽  
X Ray ◽  
Thin Film Structure ◽  
X Ray Scattering ◽  
Image Position

Abstract

Exchange Coupling and Giant Magnetoresistance in Electrodeposited Co/Cu Multilayers

1997 ◽  
Vol 475 ◽  
Author(s):  
A. Dinia ◽  
K. Rahmouni ◽  
G. Schmerber ◽  
H. El Fanity ◽  
M. Bouanani ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Giant Magnetoresistance ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Magnetoresistance Effect ◽  
X Ray ◽  
Resistivity Measurements ◽  
Fee Structure ◽  
Giant Magnetoresistance Effect ◽  
Spacer Layer

ABSTRACTWe present the results of the transport and magnetization measurements of electrodeposited Co/Cu multilayers grown in a single electrolyte based on C0SO4, H3BO3 and CuSO4. The samples are deposited on glass substrate covered by a 500 Å thick Cu buffer layer. X-ray diffraction performed on the samples shows fee structure of both Co and Cu layers with preferential (111) orientation. Resistivity measurements show a giant magnetoresistance effect of about 4% at room temperature for multilayers with Co and Cu thickness between 4 nm ≤ tco ≤ 6 nm and 3 nm ≤ tcu ≤4 nm respectively. For Co thickness tCo ≤ 15 nm, the magnetoresistance completely vanishes indicating that there is no more continuous Co layer. The indirect antiferromagnetic exchange coupling between magnetic Co layers is relatively large for 4 nm thick Cu spacer layer and gives rise to a temperature dependence of about 30% between room temperature and 4.2 K.

CoPt3 nanoparticles adsorbed on SiO2: a GISAXS and SEM study

2004 ◽  
Vol 840 ◽  
Author(s):  
Jan I. Flege ◽  
Thomas Schmidt ◽  
Gabriela Alexe ◽  
Torben Clausen ◽  
Sigrid Bernstorff ◽  
...  
Keyword(s):  
Self Assembly ◽  
Grazing Incidence ◽  
Average Particle ◽  
Particle Correlation ◽  
X Ray ◽  
Langmuir Blodgett ◽  
X Ray Scattering ◽  
Sem Study ◽  
First Time ◽  
Good Agreement

ABSTRACTUltra-thin CoPt3 nanoparticle films have been prepared on SiO2 surfaces using a Langmuir-Blodgett (LB) deposition technique. The structural properties of the overlayers have been investigated by grazing-incidence small-angle x-ray scattering (GISAXS) and high-resolution scanning electron microscopy (SEM) for the first time. Self-assembly of the nanoparticles is found and with GISAXS an average particle-particle distance of (8.23 ± 0.06) nm is determined, in good agreement with the SEM results. A particle correlation length of (22.3 ± 1.2) nm was derived which is shown to be independent of the surface coverage. The latter quantity may be controlled by choice of a suitable retraction speed during the LB step.

X-Ray Observation of Stress Gradients and Precipitation in Passivated AL-0.5% Cu Films

1993 ◽  
Vol 307 ◽  
Author(s):  
Paul R. Besser ◽  
Sean Brennan ◽  
John C. Bravman
Keyword(s):  
Room Temperature ◽  
Grazing Incidence ◽  
Synchrotron Source ◽  
X Ray ◽  
Cu Films ◽  
Stress Gradients ◽  
Inhomogeneous Strain ◽  
X Ray Scattering ◽  
Peak Broadening ◽  
Dissolution And Precipitation

ABSTRACTGrazing incidence x-ray scattering has been used with a synchrotron source to characterize the stress gradients during thermal cycling in 1.0 μm thick Al-0.5%Cu films passivated with silicon nitride. The films were cycled between room temperature and 400°C. The stress-temperature behavior is quantitatively similar to that measured for unpassivated films. The presence of an inhomogeneous strain is documented at low temperatures. The dissolution and precipitation of Al2Cu is suggested as an explanation for the gradients and asymmetric x-ray peak broadening.

Stress in Copper thin Films With Barrier Layers

1993 ◽  
Vol 309 ◽  
Author(s):  
Richard P. Vinci ◽  
John C. Bravman
Keyword(s):  
Thermal Cycle ◽  
Inverse Relationship ◽  
Room Temperature ◽  
Grazing Incidence ◽  
Dislocation Motion ◽  
X Ray ◽  
Cu Films ◽  
Barrier Layers ◽  
Dc Sputtering ◽  
X Ray Scattering

AbstractWafer curvature and grazing incidence x-ray scattering (GIXS) techniques were used to investigate the biaxial stresses induced in blanket Cu films during a thermal cycle to 460°C and back to room temperature. Cu was deposited by DC sputtering at ambient temperature. Several different barrier layer materials — SiO2, W, Ta, TiN, and Si3N4 — were used to compare any effect barrier choice might have on Cu microstructure evolution and mechanical behavior. Ta and Si3N4 encouraged a strong (111) Cu texture. A W barrier led to an untextured microstructure which underwent large, uneven grain growth during thermal cycling. Several samples were capped with a Ta layer which affected the stress behavior during cooling by inhibiting dislocation motion. An inverse relationship between strength and thickness was also documented.

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