Amplitude Dependent Damping of Aluminum-Matrix-Nanoparticle-Composites

2012 ◽  
Vol 184 ◽  
pp. 307-312 ◽  
Author(s):  
A. Kazakewitsch ◽  
Werner Riehemann
Keyword(s):  
Strain Amplitude ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Aluminum Matrix ◽  
Hot Extrusion ◽  
Density Measurements ◽  
Annealing Temperatures ◽  
Air Atmosphere ◽  
Nanoparticle Composites ◽  
Strain Dependent

Aluminum-matrix-nanoparticle-composites were produced by ball milling of micro scale aluminum powder in air atmosphere with subsequent consolidation by hot extrusion and also additional hot swaging. They were investigated in this condition after step by step isochronal annealing with successive increasing annealing temperature and quenching into water to room temperature. The material was investigated by amplitude dependent damping, hardness and density measurements, all at room temperature. For all measured amplitude dependent internal friction (ADIF) curves the damping increases with increasing strain amplitude. After some annealing treatments a knee occurs in the medium strain amplitude region of these curves. Moreover between annealing temperatures from 360°C to 480°C the strain dependent damping becomes a maximum, i.e. a peak in the ADIF curves occurs. Other ADIF curves of quenched and fatigued material show characteristic peaks that can be attributed to individual single cracks. It is shown that all these effects are due to the formation, opening and compression of cracks present in the sample or created by thermally exerted stresses.

Structural Changes of UHV Deposited Titanium Thin Films in Presence of Oxygen Flow and Temperature

2011 ◽  
Vol 110-116 ◽  
pp. 1094-1098
Author(s):  
Haleh Kangarlou ◽  
Mehdi Bahrami Gharahasanloo ◽  
Akbar Abdi Saray ◽  
Reza Mohammadi Gharabagh
Keyword(s):  
Room Temperature ◽  
Structural Changes ◽  
Annealing Temperature ◽  
Annealing Process ◽  
Oxygen Flow ◽  
Glass Substrates ◽  
Annealing Temperatures ◽  
Titanium Thin Films ◽  
Deposition Angle ◽  
Ti Films

Ti films of same thickness, and near normal deposition angle, and same deposition rate were deposited on glass substrates, at room temperature, under UHV conditions. Different annealing temperatures as 393K, 493K and 593K with uniform 8 cm3/sec, oxygen flow, were used for producing titanium oxide layers. Their nanostructures were determined by AFM and XRD methods. Roughness of the films changed due to annealing process. The gettering property of Ti and annealing temperature can play an important role in the nanostructure of the films.

About the Electrical Activation of 1×1020 cm-3 Ion Implanted Al in 4H-SiC at Annealing Temperatures in the Range 1500 - 1950°C

2018 ◽  
Vol 924 ◽  
pp. 333-338 ◽  
Author(s):  
Roberta Nipoti ◽  
Alberto Carnera ◽  
Giovanni Alfieri ◽  
Lukas Kranz
Keyword(s):  
Activation Energy ◽  
Sheet Resistance ◽  
Annealing Time ◽  
Thermal Activation ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Activation Energy ◽  
Electrical Activation ◽  
Temperature Range ◽  
Annealing Temperatures

The electrical activation of 1×1020cm-3implanted Al in 4H-SiC has been studied in the temperature range 1500 - 1950 °C by the analysis of the sheet resistance of the Al implanted layers, as measured at room temperature. The minimum annealing time for reaching stationary electrical at fixed annealing temperature has been found. The samples with stationary electrical activation have been used to estimate the thermal activation energy for the electrical activation of the implanted Al.

scholarly journals Effect of Annealing Temperature on CuInSe2/ZnS Thin-Film Solar Cells Fabricated by Using Electron Beam Evaporation

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
H. Abdullah ◽  
S. Habibi
Keyword(s):  
Electron Beam ◽  
Solar Cells ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Electron Beam Evaporation ◽  
Thin Film Solar Cells ◽  
X Ray ◽  
Annealing Temperatures ◽  
Pure Cu ◽  
Deposited Films

CuInSe2(CIS) thin films are successfully prepared by electron beam evaporation. Pure Cu, In, and Se powders were mixed and ground in a grinder and made into a pellet. The pallets were deposited via electron beam evaporation on FTO substrates and were varied by varying the annealing temperatures, at room temperature, 250°C, 300°C, and 350°C. Samples were analysed by X-ray diffractometry (XRD) for crystallinity and field-emission scanning electron microscopy (FESEM) for grain size and thickness. I-V measurements were used to measure the efficiency of the CuInSe2/ZnS solar cells. XRD results show that the crystallinity of the films improved as the temperature was increased. The temperature dependence of crystallinity indicates polycrystalline behaviour in the CuInSe2films with (1 1 1), (2 2 0)/(2 0 4), and (3 1 2)/(1 1 6) planes at 27°, 45°, and 53°, respectively. FESEM images show the homogeneity of the CuInSe2formed. I-V measurements indicated that higher annealing temperatures increase the efficiency of CuInSe2solar cells from approximately 0.99% for the as-deposited films to 1.12% for the annealed films. Hence, we can conclude that the overall cell performance is strongly dependent on the annealing temperature.

Ion Implanted p+/n Diodes: Post-Implantation Annealing in a Silane Ambient in a Cold-Wall Low-Pressure CVD Reactor

2006 ◽  
Vol 527-529 ◽  
pp. 819-822
Author(s):  
Fabio Bergamini ◽  
Shailaja P. Rao ◽  
Antonella Poggi ◽  
Fabrizio Tamarri ◽  
Stephen E. Saddow ◽  
...  
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
Low Pressure ◽  
Cold Wall ◽  
Current Voltage Characteristic ◽  
Process Yield ◽  
Annealing Temperatures ◽  
Current Voltage ◽  
Post Implantation

This work reports the realization and characterization of 4H-SiC p+/n diodes with the p+ anodes made by Al+ ion implantation at 400°C and post-implantation annealing in silane ambient in a cold-wall low-pressure CVD reactor. The Al depth profile was almost box shaped with a height of 6×1019 cm-3 and a depth of 160 nm. Implant anneals were performed in the temperature range from 1600°C to 1700°C. As the annealing temperature was increased, the silane flow rate was also increased. This annealing process yields a smooth surface with a roughness of the implanted area of 1.7 - 5.3 nm with increasing annealing temperature. The resistivity of the implanted layer, measured at room temperature, decreased for increasing annealing temperatures with a minimum value of 1.4 0-cm measured for the sample annealed at 1700°C. Considering only the current-voltage characteristic of a diode that could be modeled as an abrupt p/n junction within the frame of the Shockley theory, the diode process yield and the diode leakage current decreased, respectively, from 93% to 47% and from 2×10-7 Acm-2 to 1×10-8 Acm-2 at 100 V reverse bias, for increasing post implantation annealing temperature.

Dependence of Annealing Temperature on the Conductivity Changes of ZnO and MgZnO Nanoparticle Thin Films from Annealing in a Hydrogen Atmosphere at Mild Temperatures

2012 ◽  
Vol 1394 ◽  
Author(s):  
Christine Berven ◽  
Lorena Sanchez ◽  
Sirisha Chava ◽  
Hannah Marie Young ◽  
Joseph Dick ◽  
...  
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
Hydrogen Atmosphere ◽  
Hydrogen Gas ◽  
Maximum Temperature ◽  
Heating Process ◽  
Temperature Threshold ◽  
Annealing Temperatures ◽  
Nanoparticle Films ◽  
Current Voltage

ABSTRACTWe report apparent robust doping of ZnO and MgxZn1-xO (x ∼20%) nanoparticle films by annealing in hydrogen gas. The annealing was done at sequentially higher temperatures from about 20 °C to 140 °C. The effect of the annealing was determined by comparing current-voltage measurements of the samples at room-temperature and in vacuum after each annealing cycle.The nanoparticles were grown using an aqueous solution and heating process that created thinfilms of ZnO or MgZnO nanoparticles with diameters of about 30 nm. When exposed to hydrogen gas at room-temperature or after annealing at temperatures up to about 100 °C, no measureable changes to the room-temperature vacuum conductivity of the films was observed. However, when the samples were annealed at temperatures above 100 °C, an appreciable robust increase in the room-temperature conductance in vacuum occurred. Annealing at the maximum temperature (∼135-140 °C) resulted in about a factor of about twenty increase in the conductivity. Furthermore, the ratio of the conductance of the ZnO and MgZnO nanoparticle films while being annealed to their conductance at room-temperature were found to increase and then decrease for increasing annealing temperatures. Maximum changes of about five-fold and seven-fold for the MgZnO and ZnO samples, respectively, were found to occur at temperatures just below the annealing temperature threshold for the onset of the robust hydrogen gas doping. Comparisons of these results to other work on bulk ZnO and MgZnO films and reasons for this behavior will be discussed.

scholarly journals Current – voltage measurements of Al/a-Se/Au Schottky diode solar cells

2021 ◽  
Author(s):  
Mayyada Muttar Fdhala ◽  
◽  
Ayser A. Hemed ◽  
Ramiz A. Al-Ansari ◽  
Raad M. Al-Haddad ◽  
...  
Keyword(s):  
Power Density ◽  
Schottky Diode ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Thermal Evaporation Technique ◽  
Good Efficiency ◽  
Annealing Temperatures ◽  
Current Voltage ◽  
Evaporation Technique

Schottky Diode (SD) Al/a-Se/Au as a solar cell (SC) was prepared by thermal evaporation technique (TET) on glass thin slide as a substrate under vacuum (10!" mbar). The Schottky Barrier (SB) have been prepared with different thicknesses (300, 500 and 700) nm in room temperature and (343) K annealing temperature. The current-voltage (IV) physical properties of the SB have got rectification properties and approved as a SC. This cell is developed with increased annealing temperatures and thickness of layers of SD. Experience under lighting shows good efficiency (η), which increased linearly with both thickness and annealing temperatures from (0.0318% to 4.064%) and from (0.0318% to 0.4778%). This is for three values of lighting power density (160, 230, 400) 𝑚𝑊/𝑐𝑚# in which the behave is similar. The best efficiency obtained in this work was (15.286)% at a power density of 400 𝑚𝑊/𝑐𝑚# , with thickness 700nm and 343K annealing temperature. Also (12.407)% at 230 𝑚𝑊/𝑐𝑚#, with thickness 500nm for the same annealing temperature.

scholarly journals Effect the Thickness on the Electrical Properties and (I-V) Character of the (CdTe) Thin Films and Find the Efficiency of Solar Cell CdTe/CdS

2018 ◽  
Vol 15 (2) ◽  
pp. 192-197
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Solar Cell ◽  
Electrical Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Annealing Temperatures ◽  
Evaporation Technique ◽  
Cdte Thin Films ◽  
Vacuum Evaporation Technique

Thin films of CdTe were prepared with thickness (500, 1000) nm on the glass substrate by vacuum evaporation technique at room temperature then treated different annealing temperatures (373,473,and 573)K for one hour. Results of the Hall Effect and the electrical conductivity of (I-V) characteristics were measured in darkness and light.at different annealing temperature results show that the thin films have ability to manufacture solar cells, and found that the efficient equal to (2.18%) for structure solar cell (Algrid / CdS / CdTe /glass/ Al) and the efficient equal to (1.12%) for structure solar cell (Algrid / CdS / CdTe /Si/ Al) with thick ness of (1000) nm with CdTe thin films at RT.

Recoilless Fraction in Amorphous and Nanocrystalline FeCuNbSiB System

2012 ◽  
Vol 1520 ◽  
Author(s):  
Monica Sorescu ◽  
Tianhong Xu ◽  
Steven Herchko
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Recoilless Fraction ◽  
X Ray ◽  
Annealing Temperatures ◽  
Structural And Magnetic Properties ◽  
Fe Sites ◽  
Nanocrystalline Phases

ABSTRACTDifferential scanning calorimetry, X-ray diffraction, and room temperature Mössbauer spectrum measurements of Fe73.5Cu1Nb3Si13.5B9 (Finemet) alloy have been carried out in order to study its structural and magnetic properties as a function of annealing temperature. The Mössbauer spectra of annealed Finemet alloy could be fitted with 4 or 5 sextets and one doublet at higher annealing temperatures, revealing the appearance of different crystalline phases corresponding to the different Fe sites above the crystallization temperature. The appearance of the nanocrystalline phases at different annealing temperatures was further confirmed by the recoilless fraction measurements. These made use of our recently-developed dual absorber method, which made it possible to determine precisely the recoilless fractions of the amorphous, nanocrystalline and grain boundary phases separately.

Effect of Annealing temperature on the Structural and Magnetic Properties of TbxY3-xFe5O12(x = 0.0, 1.0, 2.0) Thin Films Prepared by Sol-Gel Process

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Garnet Phase ◽  
Sol Gel Process ◽  
Amorphous Structures

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.

Improvement of the Specific Contact Resistance on P-Type 4H-SiC by Using a Highly P-Typed Doped 4H-SiC Layer Selectively Grown by VLS Transport

2014 ◽  
Vol 806 ◽  
pp. 57-60
Author(s):  
Nicolas Thierry-Jebali ◽  
Arthur Vo-Ha ◽  
Davy Carole ◽  
Mihai Lazar ◽  
Gabriel Ferro ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Schottky Barrier Height ◽  
Annealing Temperature ◽  
Process Condition ◽  
Specific Contact Resistance ◽  
High Doping Level ◽  
Annealing Temperatures ◽  
Specific Contact ◽  
P Type

This work reports on the improvement of ohmic contacts made on heavily p-type doped 4H-SiC epitaxial layer selectively grown by Vapor-Liquid-Solid (VLS) transport. Even before any annealing process, the contact is ohmic. This behavior can be explained by the high doping level of the VLS layer (Al concentration > 1020 cm-3) as characterized by SIMS profiling. Upon variation of annealing temperatures, a minimum value of the Specific Contact Resistance (SCR) down to 1.3x10-6 Ω.cm2 has been obtained for both 500 °C and 800 °C annealing temperature. However, a large variation of the SCR was observed for a same process condition. This variation is mainly attributed to a variation of the Schottky Barrier Height.

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