Magnetotransport Properties in Semimetallic Bismuth Thin Films

2004 ◽  
Vol 449-452 ◽  
pp. 1061-1064 ◽  
Author(s):  
K.I. Lee ◽  
M.H. Jeun ◽  
J.M. Lee ◽  
J.Y. Chang ◽  
S.H. Han ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Room Temperature ◽  
The Other ◽  
Trigonal Axis ◽  
Spintronic Device ◽  
Sputtered Films ◽  
Other Hand ◽  
Device Applications

The magnetotransport properties of the electroplated and sputtered Bi thin films have been investigated in the range 4 – 300 K. A marked increase from 5,200 % to 80,000 % in the ordinary magnetoresistance (MR) for the electroplated Bi thin film was observed after thermal anneal at 4 K. The MR ratios for the as-grown and the annealed Bi thin films were found to exhibit 560 % and 590 %, respectively, at 300 K. On the other hand, the MR for the sputtered Bi film grown by sputtering was hardly observed at 4 and 300 K, whereas the MR ratios after anneal were found to reach 30,000 % at 4 K and 600 % at 300 K. We find that the room temperature MR in the sputtered films depends on the trigonal-axis oriented microstructures and grain size, in contrast to the electroplated films. Our results demonstrate the very large room temperature MR in the electroplated and sputtered Bi thin films, which can be used for spintronic device applications.

The Intercorrelation Between Microstructure and Chemicalmechanical Polish of Metal Thin Films

1999 ◽  
Vol 564 ◽  
Author(s):  
Wei-Tsu Tseng ◽  
Ying-Lang Wang
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Removal Rate ◽  
Metal Films ◽  
The Other ◽  
Metal Thin Films ◽  
Other Hand ◽  
Underlying Mechanisms ◽  
Table Speed

AbstractThe correlation between microstructures of Al and W metal thin films and their respective CMP performance is investigated. It is found that CMP removal rate decreases with increasing grain size. In both cases, the textures of the metal films are altered and their resistivity increased after CMP. The phenomenon is more pronounced for polish under a greater down force. The table speed, on the other hand, has only minimum effects on microstructure and resistivity. The possible underlying mechanisms leading to this phenomenon are proposed and their potential impacts on metallization reliability is discussed.

Physical properties of spinel iron oxide thin films

1988 ◽  
Vol 3 (2) ◽  
pp. 344-350 ◽  
Author(s):  
C. Ortiz ◽  
G. Lim ◽  
M. M. Chen ◽  
G. Castillo
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Physical Properties ◽  
Room Temperature ◽  
Lattice Parameter ◽  
Infrared Transmission ◽  
Transmission Properties ◽  
Annealing Conditions ◽  
Deposition Conditions

This paper describes the complexity of the spinel iron oxides in thin-film configuration. First, the experimental deposition conditions are determined for the parameters of substrate temperature and oxygen flow such that only the “Fe3O4” phase is formed. Then a study is made of how the structural (grain size, lattice parameter, texture), magnetic (M), and optical (visible and infrared transmission) properties of the films depend on the deposition and postdeposition (air annealing) conditions. The experimental deposition region is defined where the films have the most similar physical properties to bulk Fe3O4 and subsequently, after annealing, to bulk gamma Fe2O3. Finally, a discussion is presented of a model that accounts for the anomalous, low values of the magnetic moment for the samples deposited at room temperature. The model proposes an overpopulation of the iron tetrahedral A sites.

X-Ray Measurement of Residual Stress Distribution in Sputtered Cu Thin Films

2012 ◽  
Vol 706-709 ◽  
pp. 1649-1654 ◽  
Author(s):  
Yoshiaki Akiniwa ◽  
Taku Sakaue
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Grain Size ◽  
Stress Distribution ◽  
Residual Stress Distribution ◽  
The Other ◽  
X Ray ◽  
Maximum Value ◽  
Other Hand ◽  
Target Power

Three kinds of copper thin films were fabricated by RF-magnetron sputtering. The target power was selected to be 10 and 150 W to change the properties of the films. Thin glass sheet was used as a substrate. For the target power of 150 W, the deposition time was selected to be 7 and 40 min. The thickness was 0.6 μm and 2.9 μm, and the grain size measured was 243 nm and 450 nm, respectively. The grain size of thicker film was larger than that of thinner one. On the other hand, for the target power of 10 W, the thickness and grain size were 2.4 μm and 54 nm, respectively. The grain size depends on the target power. The residual stress distribution in the films was measured by X-ray method. Several methods such as the grazing incidence X-ray diffraction method, the constant penetration depth method and the conventional sin2ψ method were adopted. The measured weighted average stress increased with increasing depth. After taking the maximum value at about 0.3 μm from the surface, the value decreased with increasing depth. The stress distribution near the surface in the films deposited at 150 W was almost identical irrespective of thickness. On the other hand, for the target power of 10 W, the stress distribution shifted to compression side. The reason could be explained by the effect of the thermal residual stress. The real stress distribution was estimated by using the optimization technique. The stress took the maximum value at 0.5 μm from the surface, and was compressive near the substrate. .

scholarly journals Ammonia Room Temperature Gas Sensor Using Different TiO2 Nano-structure

2021 ◽  
Author(s):  
Mostafa Shooshtari ◽  
Alireza Salehi
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Room Temperature ◽  
Operating Temperature ◽  
Anatase Phase ◽  
Fold Increase ◽  
The Other ◽  
Nano Structure ◽  
Two Samples ◽  
Quartz Glasses

Abstract In this study, TiO2 Nano-structure were synthesized by three different processes including nanowires, nanoparticles and thin- films. The morphology and crystal structure of the three different TiO2 structures deposited on quartz glasses were characterized by XRD, SEM and FTIR. It has been found that nanowires and nanoparticles showed only the anatase phase while the thin-film exhibited both anatase and rutile phases. The three TiO2 Nano-structures were then used to fabricate gas sensors for ammonia (NH3) detection at different concentrations and various conditions. The samples fabricated with thin-film TiO2 towards 50 ppm NH3 showed a response value of 5% at room temperature, whereas the other two samples exhibited much higher values towards similar condition NH3 at room temperature. Samples with nanowires showed a three-fold increase and samples with nanoparticles exhibit a two-fold increase in response value. We have found that the response of all samples increases with elevating the operating temperature up to 200°C. Increasing the operating temperature improved the nanoparticle sensing conditions more than the other two samples. The samples using nanoparticles showed a 33% increase in response towards 50 ppm NH3 at 200°C compared to the samples with thin films at similar conditions. Further, response and recovery time were investigated and reported in this study.

Effects of radio-frequency power on structural properties and morphology of AlGaN thin film prepared by co-sputtering technique

2021 ◽  
Vol 20 (2) ◽  
pp. 14-18
Author(s):  
Nur Afiqah Othman ◽  
Nafarizal Nayan ◽  
Mohd Kamarulzaki Mustafa ◽  
Zulkifli Azman ◽  
Megat Muhammad Ikhsan Megat Hasnan ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Structural Properties ◽  
Room Temperature ◽  
Thin Film Deposition ◽  
Xrd Analysis ◽  
Amorphous Structure ◽  
Film Deposition ◽  
Rf Power

To date, the deposition of AlGaN thin film using the co-sputtering technique at room temperature has not been reported yet. The use of AlGaN for electronic devices has been widely known because of its ultra-wide bandgap. However, to deposit the AlGaN thin film and achieved high quality of AlGaN films, higher temperature or extra time deposition are needed, which is not compatible with industrial fabrication process. Here, a co-sputtering technique between two power supplies of magnetron sputtering (which are RF and HiPIMS) is introduced to deposit the AlGaN thin films. The AlGaN thin films were deposited at various RF power to study their effect on structural properties and morphology of the thin films. AlGaN films were sputtered simultaneously on silicon (111) substrate for short time and at room temperature using GaN and Al target. Then, the films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), and surface profiler to study their properties. XRD shows the GaN (101) and (013) plane for the AlGaN deposited at RF power of 30 W. Also there only GaN (101) for the AlGaN with 50 W RF power. Yet, the 70 W RF power shows the amorphous structure of AlGaN. The roughness and the grain size of AlGaN film from AFM analysis showed the trend of decreasing and increasing respectively. The roughness of the AlGaN films with 30 W power was 0.82 nm, 0.85 nm for 50 W, and 0.46 nm for 70 W RF power.  The grain size of the AlGaN films was 30.06 nm, 32.10 nm, and 37.65 nm for RF power of 30 W, 50 W, and 70 W respectively. The profilometer found that the thickness of the AlGaN films was decreasing with increasing of RF power. This paper can demonstrate a successful co-sputtering technique of AlGaN. Despite AlGaN crystal structure was not able to found out in the XRD analysis, the effect of RF power has been studied to give significant effects on AlGaN thin film deposition.

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.

scholarly journals Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Integrated Circuits ◽  
Film Thickness ◽  
Depth Range ◽  
Micro Electro Mechanical Systems ◽  
Si Substrates ◽  
Sio2 Thin Film ◽  
Average Grain Size

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

A facile room temperature chemical transformation approach for binder-free thin film formation of Ag2Te and lithiation/delithiation chemistry of the film

2016 ◽  
Vol 45 (43) ◽  
pp. 17312-17318 ◽  
Author(s):  
Eun-Kyung Kim ◽  
Dasom Park ◽  
Nabeen K. Shrestha ◽  
Jinho Chang ◽  
Cheol-Woo Yi ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Aqueous Solution ◽  
Ion Exchange ◽  
Chemical Transformation ◽  
Room Temperature ◽  
Film Formation ◽  
Synthetic Method ◽  
Binder Free ◽  
Thin Film Formation

An aqueous solution based synthetic method for binder-free Ag2Te thin films using ion exchange induced chemical transformation of Ag/AgxO thin films.

scholarly journals Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

2013 ◽  
Vol 9 ◽  
pp. 8-14 ◽  
Author(s):  
Yan Sun ◽  
Jing Sun ◽  
Chao-Guo Yan
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Room Temperature ◽  
The Other ◽  
Other Hand ◽  
Three Component Reaction ◽  
High Yields

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.

Synthesis of CaWO4:(Eu3+,Tb3+) Thin Films by a Two-Step Method at Room Temperature

2013 ◽  
Vol 710 ◽  
pp. 170-173
Author(s):  
Lian Ping Chen ◽  
Yuan Hong Gao
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Composition ◽  
Room Temperature ◽  
Electrochemical Techniques ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Step Method ◽  
X Ray ◽  
Rare Earth Doped

It is hardly possible to obtain rare earth doped CaWO4thin films directly through electrochemical techniques. A two-step method has been proposed to synthesize CaWO4:(Eu3+,Tb3+) thin films at room temperature. X-ray diffraction, energy dispersive X-ray analysis, spectrophotometer were used to characterize their phase, composition and luminescent properties. Results reveal that (Eu3+,Tb3+)-doped CaWO4films have a tetragonal phase. When the ratio of n (Eu)/n (Tb) in the solution is up to 3:1, CaWO4:(Eu3+,Tb3+) thin film will be enriched with Tb element; on the contrary, when the ratio in the solution is lower than 1:4, CaWO4:(Eu3+,Tb3+) thin film will be enriched with Eu element. Under the excitation of 242 nm, sharp emission peaks at 612, 543, 489 and 589 nm have been observed for CaWO4:(Eu3+,Tb3+) thin films.

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