Magnetoresistive effect in thin films

1967 ◽  
Vol 10 (6) ◽  
pp. 110-112
Author(s):  
N. I. Vtyurin ◽  
A. A. Kovalevich
Keyword(s):  
Thin Films ◽  
Magnetoresistive Effect

scholarly journals Magnetotransport properties of Coх(MgF2)100-x oxygen-free nanocomposites

2018 ◽  
Vol 185 ◽  
pp. 01014
Author(s):  
Tatyana Tregubova ◽  
Oleg Stognei ◽  
Veronika Kirpan ◽  
Aleksandr Sitnikov
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Heat Treatment ◽  
Composite Structure ◽  
Electric Properties ◽  
Thermal Heating ◽  
Initial State ◽  
Co Concentration ◽  
Heating Up ◽  
Magnetoresistive Effect

Electric and magnetoresistive properties of Coх(MgF2)100-х thin films (14 ≤ x, ат. % ≤ 62) were investigated. It is established that the received films have a composite structure. Magnetoresistive and electric properties of the films in initial state and after heat treatment have been investigated. The magnetoresistive effect of the studied samples in initial state reaches 7,5% in magnetic field of 10 kOe. It is established that the composites structure is steady against thermal heating up to 250 °C. The change of composites magnetoresistive effect after heat treatment depends on the Co concentration. The particularities of the magnetoresistive changes after annealing are discussed.

Effect of In Doping on Thermoelectric and Magnetoresistive Properties of ZnO Films Prepared by RF Magnetron Sputtering

2012 ◽  
Vol 185 ◽  
pp. 37-43
Author(s):  
Liang Fang ◽  
H.B. Ruan ◽  
L.P. Peng ◽  
X.F. Yang ◽  
F. Wu ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Doping Concentration ◽  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
Absolute Value ◽  
In Doping ◽  
Structure Surface ◽  
Magnetoresistive Effect

n-doped ZnO (ZnO:In) thin films with 0~9at.% In content have been prepared by RF high magnetron sputtering on glass substrate. All the films were annealed in N2at 473K for 1h. The effect of In doping concentration on the structure, surface morphology, electrical properties,Seebeck and magnetoresistive effect of the films were investigated. It was found that the crystal quality of the films degrades, and the surface gets rough with increasing In content. The lowest resistivity of the ZnO:In thin films 6.1×10-4Ω.cm occurs at 5at.% in the target doping concentration. All the films show a striking Seebeck effect and the absolute value of the Seebeck coefficient decreases under magnetic field. Meanwhile, a positive magnetoresistance of the films was found. ZnO thin films with 1at.% In-doped is best for the thermoelectric material, which has the largest power factor of 2.1×10-4W/K2m at room temperature.

Magnetic and Magnetotransport Properties of Fe-NbO System

2015 ◽  
Vol 233-234 ◽  
pp. 579-582
Author(s):  
Anton Grebennikov ◽  
Oleg Stognei ◽  
Konstantin Semenenko ◽  
Tatijana Tregubova
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Coercive Force ◽  
Significant Influence ◽  
Granular Structure ◽  
Granular Systems ◽  
Magnetoresistive Effect

Magnetoresistive effect and electrotransport properties of Fe-NbO (13 ≤ Fe, at.% ≤ 80) thin films annealed at 600 °C has been investigated. It has been established that the samples structure contains three main phases Fe, NbO2, Fe2.9O4. Maximum of magnetoresistance in the samples does not exceed 0.3%, a coercive force is ranging from 150 to 370 Oe, depending on the Fe concentration. It is assumed that the films have a granular structure. Magnetoresistance and coercive force values, as well as the correlation between the magnetoresistance and the magnetization of the Fe-NbO samples are uncharacteristic for granular systems. It is assumed that uncharacteristic properties are due to the significant influence of ferrite Fe2.9O4 on the magnetic properties and electrotransport of the Fe-NbO films.

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.

A standard for transmission electron spectroscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 530-531 ◽  
Author(s):  
Dennis Maher ◽  
David Joy ◽  
Peggy Mochel
Keyword(s):  
Thin Films ◽  
Electron Spectroscopy ◽  
Host Lattice ◽  
Single Element ◽  
Multicomponent Systems ◽  
Transmission Electron ◽  
Major Interest ◽  
Standard Specimens ◽  
Forms Of Carbon ◽  
Electron Energy Loss

A variety of standard specimens is needed in order to systematically investigate the instrumentation, specimen, data reduction and quantitation variables in electron energy-loss spectroscopy (EELS). Pure single element specimens (e.g. various forms of carbon) have received considerable attention to date but certain elements of interest cannot be prepared directly as thin films. Since studies of the first and second row elements in two- or multicomponent systems will be of considerable importance in microanalysis using EELS, there is a need for convenient standards containing these species. For many investigations a standard should contain the desired element, or elements, homogeneously dispersed through a suitable matrix and at an accurately known concentration. These conditions may be met by the technique of implantation.Silicon was chosen as the host lattice since its principal ionization energies, EL23 = 98 eV and Ek = 1843 eV, are well removed from the K-edges of most elements of major interest such as boron (Ek = 188 eV), carbon (Ek = 283 eV), nitrogen (Ek = 400 eV) and oxygen (Ek = 532 eV).

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