scholarly journals Analisis Penambahan Doping Magnesium (Mg) pada Material Superkonduktor FeSe dengan Metode Reaksi Padatan dalam Tabung Tertutup

2019 ◽  
Vol 19 (02) ◽  
pp. 89
Author(s):  
Muhammad Ilham Maulana
Keyword(s):  
Room Temperature ◽  
Industrial Revolution ◽  
Stoichiometric Composition ◽  
Solid State Reaction Method ◽  
Superconducting Materials ◽  
Superconducting Material ◽  
Critical Temperature Tc ◽  
Properties Of Superconductors ◽  
Very High ◽  
Mg Doped

[ID] Ketergantungan manusia terhadap teknologi memasuki Revolusi Industri 4.0 sangat tinggi. Contoh penerapan inovasi di bidang teknologi informasi salah satunya adalah superkomputer dari material superkonduktor. Material superkonduktor identik dengan material non ferromagnetik karena sifatnya diamagnetis sempurna. Namun, sejak ditemukannya material superkonduktor berbasis logam ferromagnetik, penelitian terus dikembangkan, salah satunya material FeSe. Beberapa parameter yang perlu diperhatikan pada pembuatan material FeSe untuk memperoleh sifat superkonduktor terbaiknya diantaranya komposisi stoikiometri, penambahan doping, dan proses pembuatan material FeSe seperti proses pemaduan dan sintering. Dalam penelitian ini, pengaruh variasi doping Mg akan dianalisis terhadap sifat superkonduktor, morfologi, dan fasa yang terbentuk pada material superkonduktor FeSe. Material FeSe dibuat dengan metode reaksi padatan dalam tabung tertutup (Powder in Sealed Tube) secara insitu. Temperatur sintering yang digunakan 845⁰C yang ditahan selama 6 jam, dengan kenaikan temperatur 7⁰C/menit dari temperatur kamar, dan laju pendinginan normalizing. Kandidat material superkonduktor terbaik terdapat pada sampel Mg0.01Fe0.99Se. Didapatkan Temperatur kritis (Tc)onset = 15.42 K dan Tczero = 5.4 K. Morfologi sampel menunjukkan kristalisasi besar. Lalu, persentase fraksi volume fasa superkonduktornya juga merupakan yang terbesar yaitu 81.99%. [EN] Human dependence on technology into the Industrial Revolution 4.0 is very high. Example, the application of innovations in information technology is supercomputer from superconducting materials. Superconducting materials are identical from non-ferromagnetic materials because tend perfectly diamagnetic. However, since ferromagnetic-metal-based superconducting material discovered, research continues to be developed, like FeSe material. Some parameters that need to be considered in making FeSe material to obtain the best superconductor properties include stoichiometric composition, doping addition, and process of making FeSe materials like synthesis and sintering treatment. In this study, the effect of Mg-doped variations will be analyzed towards properties of superconductors, morphology, and phases formed in FeSe superconducting materials. MgxFe1-xSe made by solid-state reaction method in sealed tube (Powder in Sealed Tube) “insituely”. The sintering temperature used 845⁰C which held for 6 hours, with 7⁰C/minute temperature rise from room-temperature and normalizing cooling rate used. The best candidate superconducting material came from Mg0.01Fe0.99Se, obtained critical temperature (Tc)onset = 15.42 K, and Tczero = 5.4 K. Sample morphology shows a large crystallization. Then, the percentage fraction of the superconducting phase was also the largest, which is 81.99%.

scholarly journals Sintesis dan Analisis Penambahan Doping Magnesium (Mg) pada Material Superkonduktor FeSe dengan Metode Reaksi Padatan dalam Tabung Tertutup

2019 ◽  
Vol 19 (2) ◽  
pp. 89-94
Author(s):  
Muhammad Ilham Maulana
Keyword(s):  
Room Temperature ◽  
Industrial Revolution ◽  
Stoichiometric Composition ◽  
Solid State Reaction Method ◽  
Superconducting Materials ◽  
Superconducting Material ◽  
Critical Temperature Tc ◽  
Properties Of Superconductors ◽  
Very High ◽  
Mg Doped

[ID] Ketergantungan manusia terhadap teknologi memasuki Revolusi Industri 4.0 sangat tinggi. Contoh penerapan inovasi di bidang teknologi informasi salah satunya adalah superkomputer dari material superkonduktor. Material superkonduktor identik dengan material non ferromagnetik karena sifatnya diamagnetis sempurna. Namun, sejak ditemukannya material superkonduktor berbasis logam ferromagnetik, penelitian terus dikembangkan, salah satunya material FeSe. Beberapa parameter yang perlu diperhatikan pada pembuatan material FeSe untuk memperoleh sifat superkonduktor terbaiknya diantaranya komposisi stoikiometri, penambahan doping, dan proses pembuatan material FeSe seperti proses pemaduan dan sintering. Dalam penelitian ini, pengaruh variasi doping Mg akan dianalisis terhadap sifat superkonduktor, morfologi, dan fasa yang terbentuk pada material superkonduktor FeSe. Material FeSe dibuat dengan metode reaksi padatan dalam tabung tertutup (Powder in Sealed Tube) secara insitu. Temperatur sintering yang digunakan 845⁰C yang ditahan selama 6 jam, dengan kenaikan temperatur 7⁰C/menit dari temperatur kamar, dan laju pendinginan normalizing. Kandidat material superkonduktor terbaik terdapat pada sampel Mg0.01Fe0.99Se. Didapatkan Temperatur kritis (Tc)onset = 15.42 K dan Tczero = 5.4 K. Morfologi sampel menunjukkan kristalisasi besar. Lalu, persentase fraksi volume fasa superkonduktornya juga merupakan yang terbesar yaitu 81.99%. [EN] Human dependence on technology into the Industrial Revolution 4.0 is very high. Example, the application of innovations in information technology is supercomputer from superconducting materials. Superconducting materials are identical from non-ferromagnetic materials because tend perfectly diamagnetic. However, since ferromagnetic-metal-based superconducting material discovered, research continues to be developed, like FeSe material. Some parameters that need to be considered in making FeSe material to obtain the best superconductor properties include stoichiometric composition, doping addition, and process of making FeSe materials like synthesis and sintering treatment. In this study, the effect of Mg-doped variations will be analyzed towards properties of superconductors, morphology, and phases formed in FeSe superconducting materials. MgxFe1-xSe made by solid-state reaction method in sealed tube (Powder in Sealed Tube) “insituely”. The sintering temperature used 845⁰C which held for 6 hours, with 7⁰C/minute temperature rise from room-temperature and normalizing cooling rate used. The best candidate superconducting material came from Mg0.01Fe0.99Se, obtained critical temperature (Tc)onset = 15.42 K, and Tczero = 5.4 K. Sample morphology shows a large crystallization. Then, the percentage fraction of the superconducting phase was also the largest, which is 81.99%.

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

scholarly journals Structure and Properties of Ln2MoO6 Oxymolybdates (Ln = La, Pr, Nd) Doped with Magnesium

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Ekaterina Orlova ◽  
Elena Kharitonova ◽  
Timofei Sorokin ◽  
Alexander Antipin ◽  
Nataliya Novikova ◽  
...  
Keyword(s):  
Rare Earth ◽  
Infrared Spectroscopy ◽  
Room Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Spectroscopy Data ◽  
Structure And Properties ◽  
Hygroscopic Properties ◽  
Thermogravimetric Studies ◽  
Mg Doped

The literature data and the results obtained by the authors on the study of the structure and properties of a series of polycrystalline and single-crystal samples of pure and Mg-doped oxymolybdates Ln2MoO6 (Ln = La, Pr, Nd) are analyzed. Presumably, the high-temperature phase I41/acd of Nd2MoO6 single crystals is retained at room temperature. The reason for the loss of the center of symmetry in the structures of La2MoO6 and Pr2MoO6 and the transition to the space group I4¯c2 is the displacement of oxygen atoms along the twofold diagonal axes. In all structures, Mg cations are localized near the positions of the Mo atoms, and the splitting of the positions of the atoms of rare-earth elements is found. Thermogravimetric studies, as well as infrared spectroscopy data for hydrated samples of Ln2MoO6 (Ln = La, Pr, Nd), pure and with an impurity of Mg, confirm their hygroscopic properties.

Molecule-Based Magnets—An Overview

MRS Bulletin ◽  
2000 ◽  
Vol 25 (11) ◽  
pp. 21-30 ◽  
Author(s):  
Joel S. Miller ◽  
Arthur J. Epstein
Keyword(s):  
Low Temperature ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Magnetic Ordering ◽  
Low Density ◽  
Materials Properties ◽  
The Common ◽  
New Processing ◽  
Very High

Molecule-based magnets are a broad, emerging class of magnetic materials that expand the materials properties typically associated with magnets to include low density, transparency, electrical insulation, and low-temperature fabrication, as well as combine magnetic ordering with other properties such as photoresponsiveness. Essentially all of the common magnetic phenomena associated with conventional transition-metal and rare-earth-based magnets can be found in molecule-based magnets. Although discovered less than two decades ago, magnets with ordering temperatures exceeding room temperature, very high (∼27.0 kOe or 2.16 MA/m) and very low (several Oe or less) coercivities, and substantial remanent and saturation magnetizations have been achieved. In addition, exotic phenomena including photoresponsiveness have been reported. The advent of molecule-based magnets offers new processing opportunities. For example, thin-film magnets can be prepared by means of low-temperature chemical vapor deposition and electrodeposition methods.

ION CHANNELING AND PIXE STUDIES OF S IMPLANTATION IN GaAs

1992 ◽  
Vol 02 (02) ◽  
pp. 151-159
Author(s):  
LIU SHIJIE ◽  
WANG JIANG ◽  
HU ZAOHUEI ◽  
XIA ZHONGHUONG ◽  
GAO ZHIGIANG ◽  
...  
Keyword(s):  
Room Temperature ◽  
Dislocation Loops ◽  
Good Recovery ◽  
Electrical Measurements ◽  
X Ray ◽  
Defect Complexes ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Activation Efficiency ◽  
Very High

GaAs (100) crystals were implanted with 100 keV S+ to a dose of 3×1015 cm−2 in a nonchanneling direction at room temperature, and treated with rapid thermal annealing (RTA). He+ Rutherford backscattering and particle-induced X-ray emission in channeling mode in combination with transmission electron microscopy (TEM) were used to study the damage and the lattice location of S atoms. It is revealed that the RTA at 950 °C for 10 sec has resulted in a very good recovery of crystallinity with a few residual defects in the form of dislocation loops, and a very high substitutionality (~90%). The activation efficiency and the Hall mobility of the implanted samples are found to be low after the electrical measurements. Based on these results an extended dopant diffusion effect for the residual defects and a correlation between the electrical properties and defect complexes are suggested.

Very High Cycle Fatigue Behavior and Life Prediction of a Low Strength Weld Metal at Moderate Temperature

2011 ◽  
Author(s):  
Ming-Liang Zhu ◽  
Fu-Zhen Xuan ◽  
Zhengdong Wang
Keyword(s):  
Crack Initiation ◽  
Weld Metal ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Fatigue Properties ◽  
Dissimilar Welding ◽  
Initiation Mechanism ◽  
Metallic Inclusions ◽  
Low Strength ◽  
Very High

The fatigue properties of a low strength weld metal in a dissimilar welding joint in high cycle and very high cycle regimes were investigated by fully reversed axial tests in air at room temperature and 370°C. A clear duplex S-N curve existed as a result of the transition of fatigue failure mode from surface-induced failure to internal-induced failure at 370°C, while the S-N curve was continuously decreased at room temperature. A new model was successfully proposed to predict fatigue life, and interpret the crack initiation modes transition from surface inclusion to interior inclusion. It was concluded that cracks were initiated by competition among non-metallic inclusions, welding pores and discontinuous microstructures in high cycle regime. While in the very high cycle regime, non-metallic inclusions were the dominant crack initiation mechanism which depended on stress level, inclusion size as well as inclusion depth.

Facile preparation of polyoxometalate nanoparticles via a solid-state chemical reaction for aerobic oxidative desulfurization catalysis

2021 ◽  
Author(s):  
Hang Yu ◽  
Wenwen Bu ◽  
Zijia Wang ◽  
Zhuoyue Zhao ◽  
Mehwish Jadoon ◽  
...  
Keyword(s):  
Solid State ◽  
Silver Nitrate ◽  
Chemical Reaction ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Oxidative Desulfurization ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
State Chemical ◽  
Facile Preparation

Polyoxometalate nanoparticles were synthesized via a concise solid-state reaction method by directly grinding silver nitrate and the polyoxometalate (NH4)5H6PMo4V8O40 at room temperature without the assistance of a surfactant.

Annealing Kinetics of Amorphous Silicon Alloy Solar Cells Made at Various Deposition Rates

2001 ◽  
Vol 664 ◽  
Author(s):  
Baojie Yana ◽  
Jeffrey Yanga ◽  
Kenneth Lord ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
High Frequency ◽  
Room Temperature ◽  
Defect Density ◽  
Very High Frequency ◽  
Solar Cell Performance ◽  
Kinetics Of ◽  
Very High

ABSTRACTA systematic study has been made of the annealing kinetics of amorphous silicon (a-Si) alloy solar cells. The cells were deposited at various rates using H2 dilution with radio frequency (RF) and modified very high frequency (MVHF) glow discharge. In order to minimize the effect of annealing during light soaking, the solar cells were degraded under 30 suns at room temperature to quickly reach their saturated states. The samples were then annealed at an elevated temperature. The J-V characteristics were recorded as a function of annealing time. The correlation of solar cell performance and defect density in the intrinsic layer was obtained by computer simulation. Finally, the annealing activation energy distribution (Ea) was deduced by fitting the experimental data to a theoretical model. The results show that the RF low rate solar cell with high H2 dilution has the lowest Ea and the narrowest distribution, while the RF cell with no H2 dilution has the highest Ea and the broadest distribution. The MVHF cell made at 8Å/s withhigh H2 dilution shows a lower Ea and a narrower distribution than the RF cell made at 3 Å/s, despite the higher rate. We conclude that different annealing kinetics plays an important role in determining the stabilized performance of a-Si alloy solar cells.

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