Effect of the interplay between layering sequence permutations and thickness on the magnetic features of Fe/Ni/Gd hetero-films

2020 ◽  
Vol 22 (21) ◽  
pp. 12082-12091
Author(s):  
Junais Habeeb Mokkath

The effect of the interplay between layering sequence permutations and film thickness on the temperature-dependent magnetization and spin structure of Fe/Ni/Gd hetero-films (sizes: 10 nm × 10 nm × d nm and 20 nm × 20 nm × d nm, where d is the film thickness and with all possible layer sequence permutations) is investigated in the framework of an atomistic spin dynamics formalism.

Author(s):  
T.E. Pratt ◽  
R.W. Vook

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.


2008 ◽  
Vol 55-57 ◽  
pp. 493-496
Author(s):  
Wisanu Pecharapa ◽  
P. Potirak ◽  
W. Yindeesuk

II-VI inorganic/organic heterostructures consisting of ZnSe and tris(8-hydroxyquinoline) aluminum (Alq3) were prepared by electron beam evaporator. Alq3 layer with 20 nm was grown between 200-nm ZnSe layers. Photoluminescence measurement was conducted at various temperatures in order to investigate the important temperature-dependent parameters of this structure. PL spectra revealed thermal population of exciton state and the change in PL quantum efficiency of the film.


1999 ◽  
Vol 595 ◽  
Author(s):  
P. Ruterana ◽  
G. Nouet ◽  
Th. Kehagias ◽  
Ph. Komninou ◽  
Th. Karakostas ◽  
...  

AbstractWhen the stoichiometric TiN was deposited directly on GaN, we obtained columnar TiN grains of 5-20 nm section which cross the whole film thickness and are rotated mostly around the [111] axis. The conventional epitaxial relationship is obtained and no amorphous patches are observed at the interface. The deposition of TiN on Si doped GaN layers lead to the formation of an ohmic contact, whereas we obtain a rectifying contact on p type layers.


2000 ◽  
Vol 660 ◽  
Author(s):  
Xiang Zhou ◽  
Andreas Nollau ◽  
Jan Blochwitz ◽  
Martin Pfeiffer ◽  
Torsten Fritz ◽  
...  

ABSTRACTWe investigate the electrical properties and the OLED application of controlledly doped amorphous hole transporters. Thin films of starburst amine, 4,4',4“-tris(N,N-diphenyl- amino) triphenylamine (TDATA), doped by a fully fluorinated form of tetracyano- quinodimethane (F4-TCNQ), are characterized in situ by temperature dependent conductivity and Seebeck measurements. The conductivity and hole concentration increase with dopant concentration and are many orders of magnitude higher than those of undoped material. OLED devices with the layer sequence ITO/TDATA(200 nm)/Alq3(65 nm)/LiF(1 nm)/Al were fabricated. The use of p-doped TDATA thin films with high bulk conductivity and hole concentration reduces the resistance of the devices and leads to a thinner space charge layer which facilitates injection of holes from the ITO anode.


2001 ◽  
Vol 690 ◽  
Author(s):  
Mark E. Overberg ◽  
Gerald T. Thaler ◽  
Rachel M. Frazier ◽  
Brent P. Gila ◽  
Cammy R. Abernathy ◽  
...  

ABSTRACTEpitaxial growth of the ferromagnetic semiconductors GaMnP:C and GaMnN has been investigated by Gas Source Molecular Beam Epitaxy (GSMBE). GaMnP:C films grown with 9.4% Mn are found to be p-type with hysteretic behavior to room temperature. GaMnN films grown at 700 °C with 2.8% Mn show hysteresis at 300 K, while temperature-dependent magnetization measurements indicate that the magnetism may persist to much higher temperatures (> 325 K). Samples of AlGaMnN have also been prepared for the first time that show improved surface morphology compared to GaMnN but which show only paramagnetic behavior.


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