Investigation of Ni-Al Intermetallic Thin Films

2020 ◽  
Vol 854 ◽  
pp. 140-147
Author(s):  
Vladimir N. Malikov ◽  
Alexey V. Ishkov ◽  
Alexey A. Grigorev ◽  
Denis A. Fadeev ◽  
Mihail A. Ryasnoi
Keyword(s):  
Electrical Conductivity ◽  
Ultrathin Films ◽  
Thermal Evaporation ◽  
High Vacuum ◽  
Optical Microscope ◽  
Scanning Probe ◽  
Kinetic Characteristics ◽  
Film Sample ◽  
Thermal Evaporation Method ◽  
Probe Microscope

The article describes the results of studies of Ni-Al ultrathin films obtained by the resistive thermal evaporation method and having the characteristic dimensions of islands of 700-1000 nm with a film thickness of about 500 nm. This paper presents a method of obtaining a film using a unit for creating high vacuum and the subsequent deposition of the film. The obtained film sample was studied using an optical microscope, a scanning probe microscope and a Fourier analyzer. The kinetic characteristics of the film, the film relief, and the characteristic dimensions of the islands were established; the search for regularities in the island structure of films was carried out and its electrical conductivity was determined.

scholarly journals Preparation of InSe Thin Films by Thermal Evaporation Method and Their Characterization: Structural, Optical, and Thermoelectrical Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Sarita Boolchandani ◽  
Subodh Srivastava ◽  
Y. K. Vijay
Keyword(s):  
Thin Films ◽  
Seebeck Coefficient ◽  
Thermoelectric Power ◽  
Temperature Variation ◽  
Thermal Evaporation ◽  
Low Cost ◽  
High Vacuum ◽  
Power Measurement ◽  
Thermal Evaporation Method ◽  
Evaporation Method

The indium selenium (InSe) bilayer thin films of various thickness ratios, InxSe(1-x) (x = 0.25, 0.50, 0.75), were deposited on a glass substrate keeping overall the same thickness of 2500 Ǻ using thermal evaporation method under high vacuum atmosphere. Electrical, optical, and structural properties of these bilayer thin films have been compared before and after thermal annealing at different temperatures. The structural and morphological characterization was done using XRD and SEM, respectively. The optical bandgap of these thin films has been calculated by Tauc’s relation that varies within the range of 1.99 to 2.05 eV. A simple low-cost thermoelectrical power measurement setup is designed which can measure the Seebeck coefficient “S” in the vacuum with temperature variation. The setup temperature variation is up to 70°C. This setup contains a Peltier device TEC1-12715 which is kept between two copper plates that act as a reference metal. Also, in the present work, the thermoelectric power of indium selenide (InSe) and aluminum selenide (AlSe) bilayer thin films prepared and annealed in the same way is calculated. The thermoelectric power has been measured by estimating the Seebeck coefficient for InSe and AlSe bilayer thin films. It was observed that the Seebeck coefficient is negative for InSe and AlSe thin films.

scholarly journals Structure, Morphology and Opto-Electrical Properties of Nanostructured Indium Doped SnO2 Thin Films Deposited by Thermal Evaporation

2016 ◽  
Vol 12 (27) ◽  
pp. 263 ◽  
Author(s):  
Md. Mahafuzur Rahaman ◽  
Kazi Md. Amjad Hussain ◽  
Mehnaz Sharmin ◽  
Chitra Das ◽  
Shamima Choudhury
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
High Vacuum ◽  
Optical Transmittance ◽  
Visible Range ◽  
Average Crystalline Size ◽  
Thermal Evaporation Method ◽  
Double Beam

Indium doped Tin oxide (SnO2: In) thin films of various thicknesses (200-600 nm) with fixed 2% indium (In) concentration were prepared by thermal evaporation method onto glass substrates under high vacuum (10-6 Torr). As deposited films were vacuum annealed at 200o C for 60 minutes. The structure, optical, electrical and morphology properties of SnO2: In thin films were investigated as a function of film thickness. The XRD analysis revealed that films were polycrystalline in nature with a tetragonal structure having (110) plane as the preferred orientation. The average crystalline size increased from 34.8 to 51.25 nm with increase of film thicknesses. The surface morphology of the doped films was obtained by Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscope (FESEM). Optical transmittance was obtained from a double beam UV-Vis- NIR spectrophotometer. Maximum transmittance varied from 65-76% in the visible range of the spectrum. Optical band gap (Eg) varied between 2.89 and 3.20 eV. The resistivity of SnO2: In thin films was as high as 105 Ω-cm. Activation energy of the films were found to be 0.18 to 0.47 eV for 300-600 nm film thicknesses. Due to high optical band gap and high electrical resistivity, these nanostructured films can be used in optoelectronic devices especially as opto-insulator.

scholarly journals Influence of electrospray deposition on C60 molecular assemblies

2021 ◽  
Vol 12 ◽  
pp. 552-558
Author(s):  
Antoine Hinaut ◽  
Sebastian Scherb ◽  
Sara Freund ◽  
Zhao Liu ◽  
Thilo Glatzel ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Thermal Evaporation ◽  
Molecular Level ◽  
High Vacuum ◽  
Good Alternative ◽  
Scanning Probe ◽  
Deposition Method ◽  
Electrospray Deposition ◽  
Molecular Assemblies ◽  
Oxide Substrates

Maintaining clean conditions for samples during all steps of preparation and investigation is important for scanning probe studies at the atomic or molecular level. For large or fragile organic molecules, where sublimation cannot be used, high-vacuum electrospray deposition is a good alternative. However, because this method requires the introduction into vacuum of the molecules from solution, clean conditions are more difficult to be maintained. Additionally, because the presence of solvent on the surface cannot be fully eliminated, one has to take care of its possible influence. Here, we compare the high-vacuum electrospray deposition method to thermal evaporation for the preparation of C60 on different surfaces and compare, for sub-monolayer coverages, the influence of the deposition method on the formation of molecular assemblies. Whereas the island location is the main difference for metal surfaces, we observe for alkali halide and metal oxide substrates that the high-vacuum electrospray method can yield single isolated molecules accompanied by surface modifications.

Scanning probe metrology

1992 ◽  
Vol 50 (2) ◽  
pp. 1124-1125
Author(s):  
Joseph E. Griffith
Keyword(s):  
High Vacuum ◽  
Three Dimensions ◽  
Scanning Probe ◽  
Dimensional Metrology ◽  
Position Measurement ◽  
Lattice Constants ◽  
Measurement Tools ◽  
Tube Position ◽  
Probe Microscope ◽  
Electron Microscopes

Scanning probe microscopes have unusual advantages as measurement tools. They achieve high resolution simultaneously in all three dimensions, over almost any solid, in ambients ranging from high vacuum to fluid electrolytes. They offer the prospect of performing dimensional metrology at the atomic level with the calibration linked directly to crystal lattice constants. Application of these microscopes to measurement is not completely straightforward, however. As with optical and electron microscopes, accurate measurement is not possible without a thorough understanding of the instrument's properties. We discuss here two aspects of probe microscope behavior that affect position measurement because they exhibit strong nonlinearities.The piezo ceramic actuators commonly used to generate the probe motion are ferroelectric so they suffer from hysteresis and creep. Consequently, the probe motion must be independently monitored. We have adopted a capacitive scheme for monitoring the probe position in all three dimensions. This scheme allows the tube position to be measured to within 10 nm, though there are distortions caused by the tube bending that must be corrected.

scholarly journals Fabrication of Metal Alloy-Deposited Flexible MWCNT Buckypaper for Thermoelectric Applications

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jih-Hsin Liu ◽  
Hsin-Yuan Miao ◽  
Saravanan Lakshmanan ◽  
Li-Chih Wang ◽  
Ren-Hui Tsai
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermal Evaporation ◽  
Multiwall Carbon Nanotubes ◽  
Metal Alloys ◽  
Thermal Evaporation Method ◽  
In Series ◽  
Multiwall Carbon ◽  
Temperature Resistivity

We report the fabrication of a flexible network of multiwall carbon nanotubes (MWCNTs) known as buckypaper (BP) for thermoelectric (TE) applications. A thermal evaporation method was used to deposit TE metal alloys onto the BP. The TE properties were improved primarily by increasing the Seebeck coefficient values (50 and 75 μV/K) and the electrical conductivity by approximately 10 000 S/m. High-temperature resistivity studies were performed to confirm the semiconductivity of buckypaper. Variations in resistivity were observed to be the result of the metal alloys coated on the BP surface. We also demonstrated that a substantial increase in the Seebeck coefficient values can be obtained by connecting 3 and 5 layers of metal-deposited BP in series, thereby enhancing the TE efficiency of MWCNT-based BP for application in thermoelectric devices.

scholarly journals Large area scanning probe microscope in ultra-high vacuum demonstrated for electrostatic force measurements on high-voltage devices

2015 ◽  
Vol 6 ◽  
pp. 2485-2497 ◽  
Author(s):  
Urs Gysin ◽  
Thilo Glatzel ◽  
Thomas Schmölzer ◽  
Adolf Schöner ◽  
Sergey Reshanov ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Electrostatic Force ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Probe ◽  
Electrostatic Force Microscopy ◽  
Kelvin Probe ◽  
Large Area ◽  
Force Microscopy ◽  
Probe Microscope

Background: The resolution in electrostatic force microscopy (EFM), a descendant of atomic force microscopy (AFM), has reached nanometre dimensions, necessary to investigate integrated circuits in modern electronic devices. However, the characterization of conducting or semiconducting power devices with EFM methods requires an accurate and reliable technique from the nanometre up to the micrometre scale. For high force sensitivity it is indispensable to operate the microscope under high to ultra-high vacuum (UHV) conditions to suppress viscous damping of the sensor. Furthermore, UHV environment allows for the analysis of clean surfaces under controlled environmental conditions. Because of these requirements we built a large area scanning probe microscope operating under UHV conditions at room temperature allowing to perform various electrical measurements, such as Kelvin probe force microscopy, scanning capacitance force microscopy, scanning spreading resistance microscopy, and also electrostatic force microscopy at higher harmonics. The instrument incorporates beside a standard beam deflection detection system a closed loop scanner with a scan range of 100 μm in lateral and 25 μm in vertical direction as well as an additional fibre optics. This enables the illumination of the tip–sample interface for optically excited measurements such as local surface photo voltage detection. Results: We present Kelvin probe force microscopy (KPFM) measurements before and after sputtering of a copper alloy with chromium grains used as electrical contact surface in ultra-high power switches. In addition, we discuss KPFM measurements on cross sections of cleaved silicon carbide structures: a calibration layer sample and a power rectifier. To demonstrate the benefit of surface photo voltage measurements, we analysed the contact potential difference of a silicon carbide p/n-junction under illumination.

scholarly journals Analysis of AC-Conductivity in Chalcogenide Ge10Se20 Bi80Thin Film

2016 ◽  
Vol 13 (2) ◽  
pp. 110-115 ◽  
Author(s):  
Shiveom Srivastav
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Conduction Mechanism ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Melt Quenching ◽  
Thermal Evaporation Method ◽  
Correlated Barrier Hopping ◽  
Dominant Conduction Mechanism

The alloy Ge10Se20 Bi80 has been prepared. Thin films of Ge10Se20 Bi80 has been prepared via a thermal evaporation method (melt quenching technique) with 3000A thickness, and rate of deposition (4.1) A/sec at pressure 2x10-5 Torr. The A.C electrical conductivity of a- thin films Ge10Se20 Bi80 has been studied as a function of frequency for annealing temperature within the range (423-623) K, the deduced exponent s values, was found to decrease with increasing of annealing temperature through the frequency of the range (102-106) Hz. It was found that, the correlated barrier hopping (CBH) is the dominant conduction mechanism. Values of dielectric constant ε1 and dielectric loss ε2 were found to decrease with frequency and increase with temperature. The activation energies have been calculated for the annealed thin films.

Sign in / Sign up

Export Citation Format

Share Document