scholarly journals Antiferromagnetic Ordering and Uncoupled Spins in CaFe 2 O 4 Thin Films Probed by Spin Hall Magnetoresistance

2021 ◽  
pp. 2100963
Author(s):  
Silvia Damerio ◽  
Alexey A. Kaverzin ◽  
Václav Ocelík ◽  
Geert R. Hoogeboom ◽  
Bart J. van Wees ◽  
...  
Keyword(s):  
Thin Films ◽  
Antiferromagnetic Ordering

Strain induced super-paramagnetism in Cr2O3 in the ultra thin film limit

2015 ◽  
Vol 1729 ◽  
pp. 79-83 ◽  
Author(s):  
Iori Tanabe ◽  
Haseeb Kazi ◽  
Yuan Cao ◽  
Jack L Rodenburg ◽  
Takashi Komesu ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetic Ordering ◽  
Hysteresis Effect ◽  
Strain Effect ◽  
Temperature Hysteresis ◽  
Antiferromagnetic Ordering ◽  
Show Evidence ◽  
Higher Temperature ◽  
Ultra Thin Film

ABSTRACTUltra thin films of chromia (Cr2O3), less than 3 nm thick, grown epitaxial on α-Al2O3 (sapphire), and are thus compressively strained in-plane. The resulting films show evidence of some magnetic ordering above the Néel temperature of chromia (307 K). The observed higher temperature hysteresis effect observed are very likely a strain effect, and not associated with the typical antiferromagnetic ordering expected of chromia.

ESR STUDY OF CuO BULK POWDER AND THIN FILMS

1992 ◽  
Vol 06 (16n17) ◽  
pp. 1043-1047 ◽  
Author(s):  
ALEX PUNNOOSE ◽  
JILSON MATHEW ◽  
B. P. MAURYA ◽  
MOHD. UMAR ◽  
R. J. SINGH
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Resonance Investigation ◽  
Antiferromagnetic Ordering ◽  
Bulk Powder ◽  
Complete Destruction ◽  
Spin Resonance ◽  
Different Temperatures ◽  
Electron Spin Resonance Investigation ◽  
Film Form

A systematic Electron Spin Resonance investigation is carried out in CuO bulk powder and thin films, after calcining them to different temperatures ranging from 100°C to 1000°C. In CuO powder, two separate signals (one broad and one sharp) were observed at calcination temperature of 500°C, for the fist time. They got intensified, came closer and amalgamated on further heating upto 800°C, indicating complete destruction of antiferromagnetic ordering in this powdered compound. In thin films of CuO, the first appearance of the signal at 200°C and its intensification and shifting on further heating indicates that in thin film form, the destruction of antiferromagnetism takes place much earlier.

PrBa2Cu3Ox Superconducting Powders

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3254-3258 ◽  
Author(s):  
J. C. Cooley ◽  
W, L. Hults ◽  
E. J. Peterson ◽  
J. L. Smith
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Magnetic Properties ◽  
Sample Preparation ◽  
Single Crystals ◽  
Single Phase ◽  
Antiferromagnetic Ordering

We have been preparing polycrystalline PrBa2Cu3O x (PBCO) to look for superconductivity at 89 K as has been reported in single crystals and thin films. We have found two transitions one at ≈ 90 K and another one at ≈ 12 K in samples, which we are still unable to make single phase. Additional phases include PrBaO 3 and BaCuO 2. The PBCO samples all appear to have the usual YBCO crystal structure and this is the phase that we believe contains the ≈ 90 K transition. The ≈ 12 K transition is most likely antiferromagnetic ordering of the PrBaO 3 phase. We are continuing to investigate sample preparation. Here we present and discuss the superconducting and magnetic properties of our samples.

The study of interfacial reactions of nickel thin films on GaAs

1983 ◽  
Vol 41 ◽  
pp. 156-157
Author(s):  
L.J. Chen ◽  
Y.F. Hsieh
Keyword(s):  
Thin Films ◽  
Integrated Circuits ◽  
Interfacial Reactions ◽  
Metal Contacts ◽  
Nickel Thin Films ◽  
Thin Foils ◽  
The Status ◽  
Si Doped ◽  
Electron Microscopes

One measure of the maturity of a device technology is the ease and reliability of applying contact metallurgy. Compared to metal contact of silicon, the status of GaAs metallization is still at its primitive stage. With the advent of GaAs MESFET and integrated circuits, very stringent requirements were placed on their metal contacts. During the past few years, extensive researches have been conducted in the area of Au-Ge-Ni in order to lower contact resistances and improve uniformity. In this paper, we report the results of TEM study of interfacial reactions between Ni and GaAs as part of the attempt to understand the role of nickel in Au-Ge-Ni contact of GaAs.N-type, Si-doped, (001) oriented GaAs wafers, 15 mil in thickness, were grown by gradient-freeze method. Nickel thin films, 300Å in thickness, were e-gun deposited on GaAs wafers. The samples were then annealed in dry N2 in a 3-zone diffusion furnace at temperatures 200°C - 600°C for 5-180 minutes. Thin foils for TEM examinations were prepared by chemical polishing from the GaA.s side. TEM investigations were performed with JE0L- 100B and JE0L-200CX electron microscopes.

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Nucleation and Early Growth of Sputtered thin Films

1970 ◽  
Vol 28 ◽  
pp. 516-517
Author(s):  
Dudley M. Sherman ◽  
Thos. E. Hutchinson
Keyword(s):  
Thin Films ◽  
Electron Beam ◽  
Ion Beam ◽  
Ion Source ◽  
Water Cooling ◽  
Stages Of Growth ◽  
Lens Assembly ◽  
Microscope Technique ◽  
Ion Beam Sputter Deposition

The in situ electron microscope technique has been shown to be a powerful method for investigating the nucleation and growth of thin films formed by vacuum vapor deposition. The nucleation and early stages of growth of metal deposits formed by ion beam sputter-deposition are now being studied by the in situ technique.A duoplasmatron ion source and lens assembly has been attached to one side of the universal chamber of an RCA EMU-4 microscope and a sputtering target inserted into the chamber from the opposite side. The material to be deposited, in disc form, is bonded to the end of an electrically isolated copper rod that has provisions for target water cooling. The ion beam is normal to the microscope electron beam and the target is placed adjacent to the electron beam above the specimen hot stage, as shown in Figure 1.

Macromolecular structures of biological specimens are not obscured by controlled osmium impregnation

1983 ◽  
Vol 41 ◽  
pp. 606-607
Author(s):  
Klaus-Ruediger Peters ◽  
Samuel A. Green
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Critical Point ◽  
Metal Films ◽  
High Magnification ◽  
Osmium Impregnation ◽  
Instrumental Resolution ◽  
20 Nm ◽  
Continuous Metal

High magnification imaging of macromolecules on metal coated biological specimens is limited only by wet preparation procedures since recently obtained instrumental resolution allows visualization of topographic structures as smal l as 1-2 nm. Details of such dimensions may be visualized if continuous metal films with a thickness of 2 nm or less are applied. Such thin films give sufficient contrast in TEM as well as in SEM (SE-I image mode). The requisite increase in electrical conductivity for SEM of biological specimens is achieved through the use of ligand mediated wet osmiuum impregnation of the specimen before critical point (CP) drying. A commonly used ligand is thiocarbohvdrazide (TCH), first introduced to TEM for en block staining of lipids and glvcomacromolecules with osmium black. Now TCH is also used for SEM. However, after ligand mediated osinification nonspecific osmium black precipitates were often found obscuring surface details with large diffuse aggregates or with dense particular deposits, 2-20 nm in size. Thus, only low magnification work was considered possible after TCH appl ication.

The Precipitation of Si in AlCuSi Thin Films

1973 ◽  
Vol 31 ◽  
pp. 34-35 ◽  
Author(s):  
R. M. Anderson
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Heat Treatment ◽  
Solid Solution ◽  
Integrated Circuit ◽  
Copper Film ◽  
Solution Concentration ◽  
X Ray ◽  
Silicon Thin Films ◽  
Before And After

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.

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