Two-Phase Co–Cu Thin Films with Size Distribution of Ferromagnetic Nanostructures Optimum for Giant Magneto Resistance

2020 ◽  
Vol 20 (9) ◽  
pp. 5686-5692
Author(s):  
A. M. Mebed
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Size Distribution ◽  
Structural Evolution ◽  
Mean Free Path ◽  
Interface Roughness ◽  
Magnetic Feature ◽  
Homogeneous Distribution ◽  
Two Phase ◽  
Magneto Resistance

New thin-film microstructure, with a homogeneous distribution of a crystalized one phase Co-rich magnetic nanoparticles, embedded in a Cu-rich continuous paramagnetic matrix was obtained. This structure has many of the characteristics deemed optimal for Giant Magneto Resistance (GMR). These characteristics are; mean free path of the electrons in the matrix, granules/matrix interface roughness, the ferromagnetic concentration of the magnetic granules, and most importantly, the size distribution of the granules. This microstructure was created in Co-93at%Cu thin film, through spinodal decomposition after a short time of aging that reached equilibrium by a growth and coarsening process. Main goal of the present work was the enhancement of the microstructure in order to pinpoint the optimum microstructural and magnetic feature that improves the GMR sensitivity and stability in granular materials. Accordingly, Structural evolution of the thin films was controlled by the annealing time and temperature. Four-probe-technique was utilized to measure the GMR properties. GMR curve for a sample annealed at 150 °C was found to be stable and saturated even at low magnetic field (<5 kOe). Microstructural evolution and compositional analysis of the thin film was investigated using in-situ transmission electron microscopy (TEM) and the energy dispersive X-ray spectrometer (EDXS).

Nucleation And Growth of Yttria-Stabilized Zirconia Thin Films Using Combustion Chemical Vapor Deposition

2002 ◽  
Vol 756 ◽  
Author(s):  
Zhigang Xu ◽  
Jag Sankar ◽  
Sergey Yarmolenko ◽  
Qiuming Wei
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Nucleation Rate ◽  
Vapor Deposition ◽  
Liquid Fuel ◽  
Structural Evolution ◽  
Chemical Vapor ◽  
Total Metal ◽  
Vapor Deposition Technique

ABSTRACTLiquid fuel combustion chemical vapor deposition technique was successfully used for YSZ thin film processing. The nucleation rates were obtained for the samples processed at different temperatures and total-metal-concentrations in the liquid fuel. An optimum substrate temperature was found for the highest nucleation rate. The nucleation rate was increased with the total-metal-concentration. Structural evolution of the thin film in the early processing stage was studied with regard to the formation of nuclei, crystallites and final crystals on the films. The films were found to be affected by high temperature annealing. The crystals and the thin films were characterized with scanning electron microscopy.

Structural Evolution and Electric Properties of Low Content Zr-Doped BiFeO3 Thin Films

2013 ◽  
Vol 785-786 ◽  
pp. 817-820 ◽  
Author(s):  
Jin Li ◽  
Lei Wang ◽  
Liang Bian ◽  
Peng Jun Zhao ◽  
Jin Bao Xu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Properties ◽  
Structural Transition ◽  
Sol Gel ◽  
Structural Evolution ◽  
Microstructural Characterization ◽  
Rhombohedral Structure ◽  
Si Substrates ◽  
Current Characteristics

The pure and Zr-doped BiFeO3 thin films were fabricated on Pt/TiO2/SiO2/Si substrates by sol-gel method. The microstructural characterization revealed a phase structural transition from rhombohedral structure to tetragonal structure in Zr-doped BiFeO3 thin films. Compared with pureBiFeO3 thin film, the Zr-doped BiFeO3 thin films showed better dielectric and leakage current characteristics. The mechanism associated with the enhancement of the electrical properties of the thin films is also discussed.

Characteristics of W thin film deposited by indirect inductively coupled plasma assisted sputtering

2020 ◽  
Vol 10 (6) ◽  
pp. 827-833
Author(s):  
Tae Hyung Kim ◽  
Kyong Nam Kim ◽  
Dong Woo Kim ◽  
Geun Young Yeom
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Roughness ◽  
Inductively Coupled Plasma ◽  
Mean Free Path ◽  
High Melting Point ◽  
Inductively Coupled ◽  
Lower Oxygen ◽  
20 Nm ◽  
Electron Mean Free Path

Tungsten (W) has a short electron mean free path (EMFP) of 19 nm and a high melting point (3673 K), and, therefore, is being actively studied as one of the next generation thin interconnector materials replacing Cu. In this study, DC magnetron sputtering of W thin film assisted by indirect inductively coupled plasma (ICP) (where, the ICP is located near the substrate) has been investigated for the deposition of 20 nm thick W thin films with a low resistivity and the results were compared with those deposited by direct ICP assisted DC magnetron (where, the ICP is located near the DC magnetron). The W thin films deposited with the indirect ICP assisted sputtering showed the continuous decrease of the W resistivity from 76.5 (0 W) to 22.2 (500 W) Ohm-cm with the increase of ICP power. In the case of W thin film deposited with direct ICP assisted sputtering, even though the resistivity was initially decreased with the ICP power, the resistivity was increased at high ICP powers due to the increased W surface roughness. The lower W resistivity at high ICP powers for the indirect ICP assisted DC sputtering was related to the change of crystal structure to BCC from A-15 and lower oxygen content in the film due to the higher ion flux to the substrate without increasing the surface roughness.

scholarly journals In Situ X-ray Measurements to Follow the Crystallization of BaTiO3 Thin Films during RF-Magnetron Sputter Deposition

2021 ◽  
Vol 11 (19) ◽  
pp. 8970
Author(s):  
Peter Walter ◽  
Markus Ilchen ◽  
JanTorben Roeh ◽  
Wiebke Ohm ◽  
Christian Bonar Zeuthen ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Film Growth ◽  
Structural Evolution ◽  
Thin Film Growth ◽  
Structure Evolution ◽  
Special Focus ◽  
Time Resolved ◽  
X Ray

Here, we report on adding an important dimension to the fundamental understanding of the evolution of the thin film micro structure evolution. Thin films have gained broad attention in their applications for electro-optical devices, solar-cell technology, as well storage devices. Deep insights into fundamental functionalities can be realized via studying crystallization microstructure and formation processes of polycrystalline or epitaxial thin films. Besides the fundamental aspects, it is industrially important to minimize cost which intrinsically requires lower energy consumption at increasing performance which requires new approaches to thin film growth in general. Here, we present a state of the art sputtering technique that allows for time-resolved in situ studies of such thin film growth with a special focus on the crystallization via small angle scattering and X-ray diffraction. Focusing on the crystallization of the example material of BaTiO3, we demonstrate how a prototypical thin film forms and how detailed all phases of the structural evolution can be identified. The technique is shaped to enable a versatile approach for understanding and ultimately controlling a broad variety of growth processes, and more over it demonstrate how to in situ investigate the influence of single high temperature sputtering parameters on the film quality. It is shown that the whole evolution from nucleation, diffusion adsorption and grain growth to the crystallization can be observed during all stages of thin film growth as well as quantitatively as qualitatively. This can be used to optimize thin-film quality, efficiency and performance.

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.

Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

1991 ◽  
Vol 49 ◽  
pp. 1068-1069
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Ablation Process ◽  
Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 264-265
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Compound Semiconductors ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Metastable Alloys ◽  
Lower Voltage

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.

Scanning-probe microscope analysis of optical thin films: A new analytical tool in a manufacturing environment

1994 ◽  
Vol 52 ◽  
pp. 1068-1069
Author(s):  
S. P. Sapers ◽  
R. Clark ◽  
P. Somerville
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Control ◽  
Scanning Probe Microscope ◽  
Scanning Probe ◽  
List Type ◽  
Manufacturing Environment ◽  
Physical Measurements ◽  
Probe Microscope

OCLI is a leading manufacturer of thin films for optical and thermal control applications. The determination of thin film and substrate topography can be a powerful way to obtain information for deposition process design and control, and about the final thin film device properties. At OCLI we use a scanning probe microscope (SPM) in the analytical lab to obtain qualitative and quantitative data about thin film and substrate surfaces for applications in production and research and development. This manufacturing environment requires a rapid response, and a large degree of flexibility, which poses special challenges for this emerging technology. The types of information the SPM provides can be broken into three categories:(1)Imaging of surface topography for visualization purposes, especially for samples that are not SEM compatible due to size or material constraints;(2)Examination of sample surface features to make physical measurements such as surface roughness, lateral feature spacing, grain size, and surface area;(3)Determination of physical properties such as surface compliance, i.e. “hardness”, surface frictional forces, surface electrical properties.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

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