The Superconducting Energy Gap of Rb3C60 as measured by IR Transmission in Thin Films

1994 ◽  
Vol 359 ◽  
Author(s):  
Daniel Koller ◽  
Michael C. Martin ◽  
Laszlo Mihaly
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Energy Gap ◽  
Bcs Theory ◽  
Infrared Transmission ◽  
Film Resistivity ◽  
Resistivity Measurements ◽  
Superconducting Energy Gap ◽  
Ir Transmission

ABSTRACTThe superconducting energy gap of Rb3C60 has been measured by infrared transmission through a thin film. Resistivity measurements on the same samples in situ indicate a transition to superconductivity at the expected temperature, ∼30K, with distinct gap features appearing in the transmission below this temperature. The results are interpreted in terms of the BCS theory.

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.

Determination of Thermal Conductivity of Amorphous Silicon Thin Films via Non-Contacting Optical Probing

2006 ◽  
Vol 326-328 ◽  
pp. 689-692
Author(s):  
Seung Jae Moon
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Conductivity ◽  
Amorphous Silicon ◽  
Optical Transmission ◽  
Film Deposition ◽  
Transmission Measurement ◽  
Conductive Heat ◽  
Optical Transmission Measurement

The thermal conductivity of amorphous silicon (a-Si) thin films is determined by using the non-intrusive, in-situ optical transmission measurement. The thermal conductivity of a-Si is a key parameter in understanding the mechanism of the recrystallization of polysilicon (p-Si) during the laser annealing process to fabricate the thin film transistors with uniform characteristics which are used as switches in the active matrix liquid crystal displays. Since it is well known that the physical properties are dependent on the process parameters of the thin film deposition process, the thermal conductivity should be measured. The temperature dependence of the film complex refractive index is determined by spectroscopic ellipsometry. A nanosecond KrF excimer laser at the wavelength of 248 nm is used to raise the temperature of the thin films without melting of the thin film. In-situ transmission signal is obtained during the heating process. The acquired transmission signal is fitted with predictions obtained by coupling conductive heat transfer with multi-layer thin film optics in the optical transmission measurement.

Interfacial adhesion of nanoporous zeolite thin films

2006 ◽  
Vol 21 (2) ◽  
pp. 505-511 ◽  
Author(s):  
Lili Hu ◽  
Junlan Wang ◽  
Zijian Li ◽  
Shuang Li ◽  
Yushan Yan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Interfacial Adhesion ◽  
Interfacial Strength ◽  
Future Generation ◽  
In Situ Growth ◽  
Seeded Growth ◽  
Si Substrates ◽  
Film Substrate

Nanoporous silica zeolite thin films are promising candidates for future generation low-dielectric constant (low-k) materials. During the integration with metal interconnects, residual stresses resulting from the packaging processes may cause the low-k thin films to fracture or delaminate from the substrates. To achieve high-quality low-k zeolite thin films, it is important to carefully evaluate their adhesion performance. In this paper, a previously reported laser spallation technique is modified to investigate the interfacial adhesion of zeolite thin film-Si substrate interfaces fabricated using three different methods: spin-on, seeded growth, and in situ growth. The experimental results reported here show that seeded growth generates films with the highest measured adhesion strength (801 ± 68 MPa), followed by the in situ growth (324 ± 17 MPa), then by the spin-on (111 ± 29 MPa). The influence of the deposition method on film–substrate adhesion is discussed. This is the first time that the interfacial strength of zeolite thin films-Si substrates has been quantitatively evaluated. This paper is of great significance for the future applications of low-k zeolite thin film materials.

scholarly journals Thin film bi-epitaxy and transition characteristics of TiO2/TiN buffered VO2 on Si(100) substrates

MRS Advances ◽  
2016 ◽  
Vol 1 (37) ◽  
pp. 2635-2640 ◽  
Author(s):  
Adele Moatti ◽  
Reza Bayati ◽  
Srinivasa Rao Singamaneni ◽  
Jagdish Narayan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetic Properties ◽  
Frequency Factor ◽  
Misfit Strain ◽  
Buffer Layers ◽  
Intrinsic Defects ◽  
Domain Matching Epitaxy ◽  
Out Of Plane

ABSTRACTBi-epitaxial VO2 thin films with [011] out-of-plane orientation were integrated with Si(100) substrates through TiO2/TiN buffer layers. At the first step, TiN is grown epitaxially on Si(100), where a cube-on-cube epitaxy is achieved. Then, TiN was oxidized in-situ ending up having epitaxial r-TiO2. Finally, VO2 was deposited on top of TiO2. The alignment across the interfaces was stablished as VO2(011)║TiO2(110)║TiN(100)║Si(100) and VO2(110) /VO2(010)║TiO2(011)║TiN(112)║Si(112). The inter-planar spacing of VO2(010) and TiO2(011) equal to 2.26 and 2.50 Å, respectively. This results in a 9.78% tensile misfit strain in VO2(010) lattice which relaxes through 9/10 alteration domains with a frequency factor of 0.5, according to the domain matching epitaxy paradigm. Also, the inter-planar spacing of VO2(011) and TiO2(011) equals to 3.19 and 2.50 Å, respectively. This results in a 27.6% compressive misfit strain in VO2(011) lattice which relaxes through 3/4 alteration domains with a frequency factor of 0.57. We studied semiconductor to metal transition characteristics of VO2/TiO2/TiN/Si heterostructures and established a correlation between intrinsic defects and magnetic properties.

Study on preparing PLT(28) thin film and its electro-optic effect

1998 ◽  
Vol 13 (5) ◽  
pp. 1266-1270 ◽  
Author(s):  
Ai-Li Ding ◽  
Wei-Gen Luo ◽  
P. S. Qiu ◽  
J. W. Feng ◽  
R. T. Zhang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Faraday Effect ◽  
The Other ◽  
Ceramic Powders ◽  
Glass Substrates ◽  
Annealing Conditions ◽  
Electro Optic

PLT(28) thin films deposited on glass substrates were studied by two sputtering processes. One is an in situ magnetron sputtering and the other is a low-temperature magnetron sputtering. The sintered PLT ceramic powders are used as a sputtering target for both processes. The influences of sputtering and annealing conditions on structure and crystallinity of the films were investigated. The electro-optic (E-O) properties of PLT(28) thin films prepared by the two processes were determined by a technique according to Faraday effect. The researches showed the E-O properties were strongly affected by the sputtering process. The film with larger grains exhibits stronger E-O effect. The quadratic E-O coefficient of PLT(28) thin film varies in the range of 0.1 × 10−16 to 1.0 × 10−16 (m/v)2.

scholarly journals Pengembangan Metode DGT (Diffusive Gradient In Thin Film) dengan Binding Gel Fe-Al-Oksida dan Pengikat Silang N,N’-Methylenebisacrylamide untuk Penyerapan Fosfat dalam Air

2015 ◽  
pp. 20-25
Author(s):  
Asep Saefumullah ◽  
Ratsania Rahmaniati H
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Small Molecule ◽  
Aquatic Environment ◽  
Contact Time ◽  
Measurement Method ◽  
High Concentration ◽  
Accurate Analysis ◽  
Al Oxide

High concentration of phosphates in the water can lead to eutrophication which leads to uncontrolled growth of algae (algae blooming). It underlies the need for determining the concentration of phosphate in the aquatic environment. However, the concentration of phosphate may change during storage of samples so that an accurate analysis difficult to achieve unless carried out in-situ. DGT (Diffusive Gradient in Thin Films) is an in-situ measurement method developed for measuring phosphate and metal. In this study the use of Fe-Al-Oxide as a binding gel that is expected to bind phosphate with a capacity greater than ferrihydrite. N, N'-methylenebisacrylamide is used as a substitute for commercial DGT Crosslinker as crosslinking for a cheaper price and selective for small molecule. Ferrihydrite-DGT and Fe-Al-Oxide-DGT are tested with a variety of concentrations, pH, and contact time. In both methods DGT found that the pH for phosphate measurements performed at pH 3. Capacity of Fe-Al-Oxide binding gel known to be higher than the ferrihydrite binding gel with result Cferrihydrite-DGT:Cstart is 76% and CFe-Al-Oxide-DGT:Cstart is 82%.DOI :http://dx.doi.org/10.15408/jkv.v0i0.3597

Dependence of Resistivity on Thickness of Vacuum Deposited Copper Thin Films

2020 ◽  
Vol 12 (8) ◽  
pp. 1125-1129
Author(s):  
Shrutidhara Sarma
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Film Thickness ◽  
Empirical Relationship ◽  
Temperature Sensors ◽  
Vacuum Deposition ◽  
Deposition Chamber ◽  
Probe Technique ◽  
Film Resistivity ◽  
Electrical Systems

In depth understanding of resistivity of metals is of utmost importance for optimizing circuit designs and electrical systems. In this study, we investigated the relation between film thickness (in the range of 25−350 nm) and film resistivity of Cu thin films, with respect to thin film temperature sensors. The films were deposited in a vacuum deposition chamber over pyrex substrates and the film resistances were measured using 4 point probe technique. The empirical relationship established by Lacy has been used along with our experimental results in order to calculate the constants relating the filmsubstrate compatibility, which influences the change of resistivity with thickness.

High-Resolution Quadrature Photopyroelectric Spectroscopy of a-Si:H Thin Films Deposited on Silicon Wafers

1995 ◽  
Vol 49 (6) ◽  
pp. 819-824 ◽  
Author(s):  
Jun Shen ◽  
Andreas Mandelis ◽  
Andreas Othonos ◽  
Joseph Vanniasinkam
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Wave ◽  
Incident Radiation ◽  
Surface Films ◽  
Si Substrates ◽  
Wafer Substrate ◽  
Ir Transmission ◽  
Ft Ir ◽  
Lock In

The recently developed photothermal technique of quadrature photopyroelectric spectroscopy (Q-PPES) has been applied to measurements of amorphous Si thin films deposited on crystalline Si substrates. Direct, meaningful comparisons have been made between purely optical transmission in-phase (IP-PPES) spectra, and purely thermal-wave sub-gap spectra with the use of a novel noncontacting PPES instrument to record lock-in in-phase and quadrature spectra, respectively. FT-IR transmission spectra have also been obtained for a comparison with this IP-PPES optical method. The results of the present work showed that the FT-IR method performs the worst in terms of spectral resolution of thin films and sub-bandgap defect/impurity absorptions inherent in the Si wafer substrate. The optical IP-PPES channel, however, albeit more sensitive than the FT-IR technique, fails to resolve spectra from surface films thinner than 2100 Å, but is sensitive to sub-bandgap absorptions. The thermal-wave Q-PPES channel is capable of resolving thin-film spectra well below 500 Å thick and exhibits strong signal levels from the crystalline Si sub-bandgap absorptions. Depending on the surface thin-film orientation toward, or away from, the direction of the incident radiation, the estimated minimum mean film thickness resolvable spectroscopically by Q-PPES is either 40 Å or 100 Å, respectively.

scholarly journals Porous Ultra-Thin Films from Photocleavable Block Copolymers: In-Situ Degradation Kinetics Study of Pore Material

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 781 ◽  
Author(s):  
Sedakat Altinpinar ◽  
Wael Ali ◽  
Patrick Schuchardt ◽  
Pinar Yildiz ◽  
Hui Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Polymer Film ◽  
Uv Exposure ◽  
Significant Information ◽  
X Ray ◽  
Washing Process

On the basis of the major application for block copolymers to use them as separation membranes, lithographic mask, and as templates, the preparation of highly oriented nanoporous thin films requires the selective removal of the minor phase from the pores. In the scope of this study, thin film of polystyrene-block-poly(ethylene oxide) block copolymer with a photocleavable junction groups based on ortho-nitrobenzylester (ONB) (PS-hν-PEO) was papered via the spin coating technique followed by solvent annealing to obtain highly-ordered cylindrical domains. The polymer blocks are cleaved by means of a mild UV exposure and then the pore material is washed out of the polymer film by ultra-pure water resulting in arrays of nanoporous thin films to remove one block. The removal of the PEO materials from the pores was proven using the grazing-incidence small-angle X-ray scattering (GISAXS) technique. The treatment of the polymer film during the washing process was observed in real time after two different UV exposure time (1 and 4 h) in order to draw conclusions regarding the dynamics of the removal process. In-situ X-ray reflectivity measurements provide statistically significant information about the change in the layer thickness as well as the roughness and electron density of the polymer film during pore formation. 4 H UV exposure was found to be more efficient for PEO cleavage. By in-situ SFM measurements, the structure of the ultra-thin block copolymer films was also analysed and, thus, the kinetics of the washing process was elaborated. The results from both measurements confirmed that the washing procedure induces irreversible change in morphology to the surface of the thin film.

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