scholarly journals Structural, Electrical, and Optical Properties of PbTe Thin Films Prepared by Simple Flash Evaporation Method

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Lakshmanan Kungumadevi ◽  
Ramakrishnan Sathyamoorthy
Keyword(s):  
Thin Films ◽  
Optical Constants ◽  
Lead Telluride ◽  
Blue Shift ◽  
Face Centered Cubic ◽  
Flash Evaporation ◽  
Electrical And Optical Properties ◽  
Evaporation Method ◽  
Glass Substrates ◽  
Face Centered

Lead telluride (PbTe) films have been prepared on glass substrates by flash evaporation method. Structure of the film is found to possess stable face-centered cubic (fcc) NaCl phase in which the grains predominantly grow in the direction of (200) plane. The calculated grain size was in the range 19 nm. The electrical resistivity as a function of temperature was measured using four-probe technique. The electrical conductivity was calculated, and the value is found to be from 67.11 to 344.82 S/cm in the temperature range 303–453 K. The value of mobility was evaluated, and it is found to be0.329×10-3 cm2·V−1 S−1. An optical study reveals that the PbTe thin films exhibit large blue shift. The optical constants such as absorption coefficient and refractive index have been estimated, and the results are discussed.

Effect of Substrate Temperature on the Opto-Electrical Propertites of Ti Doped ITO Films Deposited by RF Magnetron Sputtering

2012 ◽  
Vol 602-604 ◽  
pp. 1399-1403
Author(s):  
Rui Xin Ma ◽  
Shi Na Li ◽  
Guo Quan Suo
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Substrate Temperature ◽  
Absorption Edge ◽  
Blue Shift ◽  
Rf Magnetron Sputtering ◽  
Electrical And Optical Properties ◽  
Glass Substrates ◽  
Visible Wavelengths

Ti doped ITO (ITO:Ti) thin films were fabricated on glass substrates by RF magnetron sputtering using only one piece of ITO:Ti ceramic target at different substrate temperature (Ts). The effect of substrate temperature on structural, electrical, and optical properties of the films was investigated. It is confirmed that the resistivity of the films decreases with the increase of Ts till the minimum value of 2.5×10-4 Ω•cm and the transmittance in visible wavelengths is higher than 90%. "Blue shift" and "red shift" of UV absorption edge of the film were observed when Ts200 °CHeaders and footers

Annealing Effects on Microstructure and Thermoelectric Properties of Bi2(Te0.95Se0.05)3 Thin Films Prepared by Flash Evaporation Method

2011 ◽  
Vol 287-290 ◽  
pp. 2434-2437
Author(s):  
Xing Kai Duan ◽  
Yue Zhen Jiang
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Flash Evaporation ◽  
Thermoelectric Power Factor ◽  
Evaporation Method ◽  
Glass Substrates ◽  
Annealing Effects ◽  
Thermoelectric Thin Films

N-type Bi2(Te0.95Se0.05)3thermoelectric thin films with thickness 800 nm have been deposited on glass substrates by flash evaporation method at 473 K. The structures, morphology of the thin films were characterized by X-ray diffraction and field emission scanning electron microscope, respectively. Thermoelectric properties of the thin films have been evaluated by measurements of Seebeck coefficient and electrical resistivity at 300 K. Annealing effect on Seebeck coefficient and electrical resistivity of the thin films was examined in the temperature range 373–573 K. When annealed at 473 K for 1 h, Seebeck coefficient and electrical resistivity are –180 μV/K and 2.7 mΩcm, respectively. Thermoelectric power factor is improved to 12 µW/cmK2.

scholarly journals Influence of Post-Annealing on the Structural and Nanomechanical Properties of Co Thin Films

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 180 ◽  
Author(s):  
Yeong-Maw Hwang ◽  
Cheng-Tang Pan ◽  
Ying-Xu Lu ◽  
Sheng-Rui Jian ◽  
Huang-Wei Chang ◽  
...  
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Face Centered Cubic ◽  
Ambient Conditions ◽  
Nanomechanical Properties ◽  
Glass Substrates ◽  
Hexagonal Close Packed ◽  
Nanoindentation Measurement ◽  
Different Temperatures ◽  
Face Centered

The correlations between the microstructure and nanomechanical properties of a series of thermal annealed Co thin films were investigated. The Co thin films were deposited on glass substrates using a magnetron sputtering system at ambient conditions followed by subsequent annealing conducted at various temperatures ranging from 300 °C to 800 °C. The XRD results indicated that for annealing temperature in the ranged from 300 °C to 500 °C, the Co thin films were of single hexagonal close-packed (hcp) phase. Nevertheless, the coexistence of hcp-Co (002) and face-centered cubic (fcc-Co (111)) phases was evidently observed for films annealed at 600 °C. Further increasing the annealing temperature to 700 °C and 800 °C, the films evidently turned into fcc-Co (111). Moreover, significant variations in the hardness and Young’s modulus are observed by continuous stiffness nanoindentation measurement for films annealed at different temperatures. The correlations between structures and properties are discussed.

scholarly journals The Effects of ? – Rays on The Optical Constants of ZnS Thin Films

2010 ◽  
Vol 7 (3) ◽  
pp. 1232-1236
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Optical Constants ◽  
Flash Evaporation ◽  
Glass Substrates ◽  
Evaporation Technique

ZnS thin films were grown onto glass substrates by flash evaporation technique, the effects of ? – rays on the optical constants of ZnS these films were studied. It was found that ? – rays affected all the parameters under investigation.

scholarly journals Study of decagonal approximant and γ-brass-type compounds in Al–Cr–Fe thin films

2004 ◽  
Vol 19 (8) ◽  
pp. 2285-2297 ◽  
Author(s):  
V. Demange ◽  
J. Ghanbaja ◽  
C. Beeli ◽  
F. Machizaud ◽  
J.M. Dubois
Keyword(s):  
Thin Films ◽  
Native Oxide ◽  
Ambient Atmosphere ◽  
Native Oxide Layer ◽  
Face Centered Cubic ◽  
Flash Evaporation ◽  
Decagonal Phase ◽  
Preparation Conditions ◽  
Face Centered ◽  
Twin Defects

This paper reports the preparation conditions and structure characteristics of Al–Cr–Fe very thin films (10–30 nm) obtained by the flash evaporation technique. The films are either amorphous or crystallized, depending on the thickness of the sample and temperature of the substrate. Annealing of amorphous films leads to crystallization of intermetallic phases that are all linked with quasicrystals. In particular, we have identified by transmission electron microscopy the following structures: body-centered-cubic (bcc) γ-brass phase, monoclinic λ–Al13(Cr,Fe)4 phase, and orthorhombic O1-phase, all of them already observed in this system, together with four new structures, i.e., a face-centered-cubic (fcc) γ-brass phase (superstructure of the bcc phase), monoclinic λ′-phase (related to the λ-phase) and two orthorhombic phases (1/1/; 1/1) and (1/0; 2/1) approximants of the decagonal phase). In this study, we point out the occurrence of twin defects of the λ–Al13(Cr,Fe)4 phase. Films prepared directly in the crystalline state comprise the O1 approximant. Electron energy loss spectroscopy measurements show that all films are not oxidized except for the presence of a native oxide layer that forms in ambient atmosphere with a thickness that cannot exceed 0.3 nm. Optical properties were investigated and show that films need to be large enough (>30 nm) to reproduce the properties of bulk alloys. Finally, contact angle wetting measurements reveal that the presence of such films on a substrate, even at very low thickness, considerably decreases the wetting behavior by water.

ON THE STRUCTURE, ELECTRICAL AND OPTICAL PROPERTIES OF TiO2 SPUTTERED THIN FILMS

2006 ◽  
Vol 13 (01) ◽  
pp. 87-92 ◽  
Author(s):  
A. ASHOUR
Keyword(s):  
Thin Films ◽  
Optical Constants ◽  
Optical Band Gap ◽  
Optical Transmittance ◽  
X Ray Diffraction ◽  
Electrical And Optical Properties ◽  
X Ray ◽  
Lattice Constants ◽  
Glass Substrates ◽  
Deposited Films

Titanium oxide thin films were prepared by sputtering technique onto glass substrates at room temperature (RT). The structure of the films was confirmed using X-ray diffraction (XRD) and revealed the stoichiometry with an O and Ti ratio of 2. The deposited films at RT were found to be amorphous and the films annealed at 300 and 400°C for 2 h were crystalline with orthorhombic structure. The lattice constants and grain size of the film are calculated. The electrical resistivity was found to depend on the film thickness and decreased with increasing the film thicknesses. The optical constants of the films such as the refractive index, extinction coefficient, and absorption coefficient were also determined using the optical transmittance measurements, and the results were discussed. The optical band gap varies from 3.2 to 3.5 eV as a function of oxygen/argon ratios.

scholarly journals Optical and Dispersion Parameters of ZnS Thin Films Prepared by Flash Evaporation Method

2014 ◽  
Vol 39 ◽  
pp. 52-63 ◽  
Author(s):  
Nabeel A. Bakr ◽  
Nidhal N. Jandow ◽  
Nadir F. Habubi
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Energy Gap ◽  
Flash Evaporation ◽  
Dispersion Parameters ◽  
Optical Energy Gap ◽  
Evaporation Method ◽  
Glass Substrates ◽  
Single Oscillator Model ◽  
Dispersion Data

Zns thin films are obtained by flash evaporation method onto preheated glass substrates. The transmittance analysis allowed the determination of refractive index and thickness using envelope method. It was found that the refractive dispersion data obeyed the single oscillator model. The calculated value of the refractive index (no) was found to be equal to 2.27, which is in a good agreement with the value obtained from Cauchy’s fitting. Also the value of the optical energy gap, extinction coefficient, real and imaginary parts of the dielectric constant and optical conductivity have been measured.

Electron diffraction detection of ordliking in annealed PbTe thin film

1990 ◽  
Vol 48 (4) ◽  
pp. 1018-1019
Author(s):  
Karimat El-Sayed
Keyword(s):  
Thin Film ◽  
Electron Diffraction ◽  
Lead Telluride ◽  
Structural Basis ◽  
Face Centered Cubic ◽  
X Ray ◽  
Polycrystalline Thin Films ◽  
Stage Process ◽  
Diffraction Patterns ◽  
Face Centered

Lead telluride is an important semiconductor of many applications. Many Investigators showed that there are anamolous descripancies in most of the electrophysical properties of PbTe polycrystalline thin films on annealing. X-Ray and electron diffraction studies are being undertaken in the present work in order to explain the cause of this anamolous behaviour.Figures 1-3 show the electron diffraction of the unheated, heated in air at 100°C and heated in air at 250°C respectively of a 300°A polycrystalline PbTe thin film. It can be seen that Fig. 1 is a typical [100] projection of a face centered cubic with unmixed (hkl) indices. Fig. 2 shows the appearance of faint superlattice reflections having mixed (hkl) indices. Fig. 3 shows the disappearance of thf superlattice reflections and the appearance of polycrystalline PbO phase superimposed on the [l00] PbTe diffraction patterns. The mechanism of this three stage process can be explained on structural basis as follows :

scholarly journals Effects of Perpendicular Magnetic Field Annealing on the Structural and Magnetic Properties of [Co/Ni]2/PtMn Thin Films

2021 ◽  
Vol 7 (3) ◽  
pp. 38
Author(s):  
Roshni Yadav ◽  
Chun-Hsien Wu ◽  
I-Fen Huang ◽  
Xu Li ◽  
Te-Ho Wu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Perpendicular Magnetic Field ◽  
Face Centered Cubic ◽  
Lattice Image ◽  
X Ray ◽  
Field Annealing ◽  
Face Centered

In this study, [Co/Ni]2/PtMn thin films with different PtMn thicknesses (2.7 to 32.4 nm) were prepared on Si/SiO2 substrates. The post-deposition perpendicular magnetic field annealing (MFA) processes were carried out to modify the structures and magnetic properties. The MFA process also induced strong interlayer diffusion, rendering a less sharp interface between Co and Ni and PtMn layers. The transmission electron microscopy (TEM) lattice image analysis has shown that the films consisted of face-centered tetragonal (fct) PtMn (ordered by MFA), body-centered cubic (bcc) NiMn (due to intermixing), in addition to face-centered cubic (fcc) Co, Ni, and PtMn phases. The peak shift (2-theta from 39.9° to 40.3°) in X-ray diffraction spectra also confirmed the structural transition from fcc PtMn to fct PtMn after MFA, in agreement with those obtained by lattice images in TEM. The interdiffusion induced by MFA was also evidenced by the depth profile of X-ray photoelectron spectroscopy (XPS). Further, the magnetic properties measured by vibrating sample magnetometry (VSM) have shown an increased coercivity in MFA-treated samples. This is attributed to the presence of ordered fct PtMn, and NiMn phases exchange coupled to the ferromagnetic [Co/Ni]2 layers. The vertical shift (Mshift = −0.03 memu) of the hysteresis loops is ascribed to the pinned spins resulting from perpendicular MFA processes.

The Characteristics of Multilayer Thin Films Deposited with Metal Thin Films (Ag, Al, Cu)

2010 ◽  
Vol 97-101 ◽  
pp. 1768-1771 ◽  
Author(s):  
Dong Hun Kim ◽  
Riichi Murakami ◽  
Yun Hae Kim ◽  
Kyung Man Moon ◽  
Seung Jung An ◽  
...  
Keyword(s):  
Thin Films ◽  
Metal Particles ◽  
Zno Thin Films ◽  
Multilayer Thin Films ◽  
Electrical And Optical Properties ◽  
Metal Thin Films ◽  
Continuous Structure ◽  
Glass Substrates ◽  
The Difference ◽  
Sputtering System

In order to study the characteristics of multilayer thin films with a ZnO/ metal/ ZnO structure the manufacture of the thin films was performed by a dc (direct current) magnetron sputtering system on slide glass substrates. The ZnO thin films were manufactured with the thicknesses of 30 nm and 50 nm. Three kinds of metals (Ag, Al and Cu) were deposited with the thicknesses of 4 nm, 8 nm, 12 nm and 16 nm. The electrical and optical properties of the manufactured thin films were then observed. As a result, the multilayer thin films with an Ag layer represented the most excellent electrical conductivity. This is due to the difference in the fundamental electrical properties of each of the metals. The structures of the metal particles deposited on the ZnO thin films were observed by an SEM (scanning electron microscope). The thin films exhibited a continuous structure with regular spaces between the metal particles. This resulted in an increase of transmittance. This is considered by the decrease of scattering and of light absorption on thin films with a continuous structure.

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