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Full-Text Articles in Engineering
Characterization Of The Elastic, Piezoelectric, And Dielectric Properties Of Langatate At High Temperatures Up To 900 ◦C, Peter Mark Davulis
Characterization Of The Elastic, Piezoelectric, And Dielectric Properties Of Langatate At High Temperatures Up To 900 ◦C, Peter Mark Davulis
Electronic Theses and Dissertations
The acoustic wave constants of the piezoelectric crystal langatate (LGT, La3Ga5.5Ta0.5O14) are characterized up to 900 ◦C for the first time in this work, targeting the development of high-temperature acoustic wave (AW) devices. There is a pressing need for sensors and frequency control systems that operate at high temperature, above 200 ◦C, and in harsh environments, with applications found in the industrial process control, automotive, aerospace, and power generation industries and in gas and petroleum exploration. Surface acoustic wave (SAW) and bulk acoustic wave (BAW) devices, using piezoelectric crystals such as LGT, have the capability to provide the desired high-temperature …
Predicting The Fate Of Emerging Trace Organic Contaminants Of Concern During Mbr Treatment Based On Their Molecular Properties, K C. Wijekoon, L D. Nghiem, F I. Hai, J Kang, W E. Price
Predicting The Fate Of Emerging Trace Organic Contaminants Of Concern During Mbr Treatment Based On Their Molecular Properties, K C. Wijekoon, L D. Nghiem, F I. Hai, J Kang, W E. Price
William E. Price
We demonstrate that the fate of emerging trace organic contaminants during membrane bioreactor (MBR) treatment can be qualitatively predicted by assessing their molecular properties. This work futher expands the qualitative framework for the prdiction of trace organic removal by MBR treatment reported in our recent study.
Changes In Surface Properties And Separation Efficiency Of A Nanofiltration Membrane After Repeated Fouling And Chemical Cleaning Cycles, Alexander Simon, William E. Price, Long D. Nghiem
Changes In Surface Properties And Separation Efficiency Of A Nanofiltration Membrane After Repeated Fouling And Chemical Cleaning Cycles, Alexander Simon, William E. Price, Long D. Nghiem
William E. Price
The aim of this study was to evaluate the changes in membrane surface properties and solute separation by a nanofiltration membrane during repetitive membrane fouling and chemical cleaning. Secondary treated effluent and model fouling solutions containing humic acids, sodium alginate, or silica colloids were used to simulate membrane fouling. Chemical cleaning was carried out using a commercially available caustic cleaning formulation. Carbamazepine and sulfamethoxazole were selected to examine the filtration behaviour of neutral and negatively charged organic compounds, respectively. Results show that the impact of membrane fouling on solute rejection is governed by pore blocking, modification of the membrane surface …
An Alternative Rail Pad Tester For Measuring Dynamic Properties Of Rail Pads Under Large Preloads, Sakdirat Kaewunruen, Alexander Remennikov
An Alternative Rail Pad Tester For Measuring Dynamic Properties Of Rail Pads Under Large Preloads, Sakdirat Kaewunruen, Alexander Remennikov
Alex Remennikov
One of the main components in ballasted railway track systems is the rail pad. It is installed between the rail and the sleeper to attenuate wheel/rail interaction loads, preventing the underlying railway sleepers from excessive stress waves. Generally, the dynamic design of tracks relies on the available data, which are mostly focused on the structural condition at a specific toe load. Recent findings show that track irregularities could significantly amplify the loads on railway tracks. This phenomenon gives rise to a concern that the rail pads may experience higher effective preloading than anticipated in the past. On this ground, this …
Magnetic Properties And Magnetocaloric Effect Of Ndmn2−Xtixsi2 Compounds, M F. Md Din, Jianli Wang, S J. Campbell, R Zeng, W D. Hutchison, M Avdeev, S J. Kennedy, S X. Dou
Magnetic Properties And Magnetocaloric Effect Of Ndmn2−Xtixsi2 Compounds, M F. Md Din, Jianli Wang, S J. Campbell, R Zeng, W D. Hutchison, M Avdeev, S J. Kennedy, S X. Dou
Australian Institute for Innovative Materials - Papers
The structural and magnetic properties of the intermetallic compounds NdMn2−xTixSi2(x = 0, 0.1, 0.2, and 0.3) have been studied by x-ray and high resolution neutron powder diffraction, specific heat, dc magnetization, and differential scanning calorimetry measurements over the temperature range 3–450 K. The Curie temperature and Néel temperature of NdMn2Si2 decrease from TC = 36 K and TN = 380 K to TC = 14 K and TN = 360 K, respectively, on substitution of Ti (x = 0.3) for Mn. The magnetocaloric effect …
Hydrothermal Synthesis And Optical, Magnetic And Supercapacitance Properties Of Nanoporous Cobalt Oxide Nanorodes, Guoxiu Wang, Xiaoping Shen, Josip Horvat, Bei Wang, Hao Liu, David Wexler, Jane Yao
Hydrothermal Synthesis And Optical, Magnetic And Supercapacitance Properties Of Nanoporous Cobalt Oxide Nanorodes, Guoxiu Wang, Xiaoping Shen, Josip Horvat, Bei Wang, Hao Liu, David Wexler, Jane Yao
Josip Horvat
Nanoporous cobalt oxide nanorods were synthesized by a hydrothermal method. Transmission electron microscopy analysis showed that the individual Co3O4 nanorods have a nanoporous structure, consisting of the textured aggregations of nanocrystals. Optical properties of Co3O4 nanorods were characterized by Raman and UV−vis spectroscopy. Magnetic property measurement shows that Co3O4 nanorods have a low Néel transition temperature of 35 K. We observed quite significant exchange bias for nanoporous Co3O4 nanorods, indicating the existence of magnetic coupling between the nanocrystals in Co3O4 nanorods. When applied as electrode materials in supercapacitors, Co3O4 demonstrated a high capacitance of 280 F/g.
Magnetic And Superconducting Properties Of Spin-Fluctuation-Limited Superconducting Nanoscale Vnx, R Zeng, J Liu, G Du, W. X. Li, J Wang, J Horvat, S X. Dou
Magnetic And Superconducting Properties Of Spin-Fluctuation-Limited Superconducting Nanoscale Vnx, R Zeng, J Liu, G Du, W. X. Li, J Wang, J Horvat, S X. Dou
Josip Horvat
"VNx nanoparticles and nanowires have been prepared by nitrifying V2O5 nanoparticles (NP) and nanowires (NW). The V2O5 NP and NW were synthesized by a facile hydrothermal method. Magnetic susceptibility (chi) and magnetization measurements showed long range superconducting ordering (LRSO) at the temperature of 5.8 K for NW, but there was no observation of LRSO (at least down to 2 K) for the NP sample, which is a much lower temperature than for the corresponding bulk, while both NP and NW showed the absence of long range magnetic ordering, at least down to 2 K. However, the chi data showed that …
Predicting The Fate Of Emerging Trace Organic Contaminants Of Concern During Mbr Treatment Based On Their Molecular Properties, K C. Wijekoon, L D. Nghiem, F I. Hai, J Kang, W E. Price
Predicting The Fate Of Emerging Trace Organic Contaminants Of Concern During Mbr Treatment Based On Their Molecular Properties, K C. Wijekoon, L D. Nghiem, F I. Hai, J Kang, W E. Price
Faisal I Hai
We demonstrate that the fate of emerging trace organic contaminants during membrane bioreactor (MBR) treatment can be qualitatively predicted by assessing their molecular properties. This work futher expands the qualitative framework for the prdiction of trace organic removal by MBR treatment reported in our recent study.
Effect Of Ti And N Concentrations On Microstructure And Mechanical Properties Of Microalloyed High Strength Line Pipe Steel Welds, Leigh Fletcher, Zhixiong Zhu, Marimuthu Murugananth, Lei Zheng, Mingzhuo Bai, Huijun Li, F Barbaro
Effect Of Ti And N Concentrations On Microstructure And Mechanical Properties Of Microalloyed High Strength Line Pipe Steel Welds, Leigh Fletcher, Zhixiong Zhu, Marimuthu Murugananth, Lei Zheng, Mingzhuo Bai, Huijun Li, F Barbaro
Muruganant Marimuthu
A selection of nine heats of line pipe steel from the same project with different Ti and N content were used to evaluate the effects of Ti/N ratio on weld zone microstructure, hardness and prior austenite grain size (PAGS) in the coarse grained heat-affected zone (CGHAZ). It was shown that the microstructure of the base metal (BM) mainly consisted of fine grained polygonal ferrite with fine islands of pearlite. The weld metal (WM) microstructure was predominantly acicular ferrite with a small volume fraction of pro-eutectoid ferrite. The CGHAZ consisted of bainitic ferrite and islands of martensite-austenite. The inside region of …
Modeling Mechanical Properties In Dual Phase Steels, Himanshu Panjiar, R Thyagarajan, M Murugananth, Sumitesh Das, Karamveer Singh
Modeling Mechanical Properties In Dual Phase Steels, Himanshu Panjiar, R Thyagarajan, M Murugananth, Sumitesh Das, Karamveer Singh
Muruganant Marimuthu
No abstract provided.
Magnetic Properties Of Ho2fe17-Xmnx - Influence Of Mn Substitution, Jianli Wang, Stewart J. Campbell, A J Studer, S J. Kennedy, Rong Zeng
Magnetic Properties Of Ho2fe17-Xmnx - Influence Of Mn Substitution, Jianli Wang, Stewart J. Campbell, A J Studer, S J. Kennedy, Rong Zeng
Jianli Wang
The structural and magnetic properties of Ho2Fe17−xMnx (x=0-5) have been investigated by x-ray diffraction, Mössbauer spectroscopy and DC magnetization measurements (0-5 T) over the temperature range 4.5-350 K. Similar to other ferrimagnetic R2Fe17-xMnx systems, the unit cell volume generally increases with Mn content other than for low Mn values where a slight maximum is detected around x ∼ 0.5. The nature of the magnetic phase transitions around TC is shown by Arrot plot analysis to be second order for all samples. The Curie temperature remains essentially unchanged …
Magnetic Properties In Polycrystalline And Single Crystal Ca-Doped Lacoo3, R Zeng, J C. Debnath, Dapeng Chen, P Shamba, Jianli Wang, S J. Kennedy, S J. Campbell, Tania M. Silver, S. X. Dou
Magnetic Properties In Polycrystalline And Single Crystal Ca-Doped Lacoo3, R Zeng, J C. Debnath, Dapeng Chen, P Shamba, Jianli Wang, S J. Kennedy, S J. Campbell, Tania M. Silver, S. X. Dou
Jianli Wang
Polycrystalline (PC) and single crystalline (SC) Ca-doped LaCoO3 (LCCO) samples with the perovskite structure were synthesized by conventional solid-state reaction and the floating-zone growth method. We present the results of a comprehensive investigation of the magnetic properties of the LCCO system. Systematic measurements have been conducted on dc magnetization, ac susceptibility, exchange-bias, and the magnetocaloric effect. These findings suggest that complex structural phases, ferromagnetic (FM), and spin-glass/cluster-spin-glass (CSG), and their transitions exist in PC samples, while there is a much simpler magnetic phase in SC samples. It was also of interest to discover that the CSG induced a magnetic field …
Magnetovolume Effect And Magnetic Properties Of Dy2fe17-Xmnx, Jianli Wang, Stewart J. Campbell, O Tegus, C Marquina, M R. Ibarra
Magnetovolume Effect And Magnetic Properties Of Dy2fe17-Xmnx, Jianli Wang, Stewart J. Campbell, O Tegus, C Marquina, M R. Ibarra
Jianli Wang
The structural and magnetic properties of Dy2Fe17−xMnx (x=0–5) compounds have been investigated using x-ray diffraction, linear thermal expansion, magnetization measurements, and 57Fe Mössbauer spectroscopy. Compared with Dy2Co17−xMnx compounds for which a linear increase of the unit-cell volume V with increasing Mn fraction is found, the compositional dependence of the lattice parameters of Dy2Fe17−xMnx first exhibits a slight maximum around x=0.5 before increasing monotonically with further increase in x; this behavior can be ascribed to a spontaneous magnetostriction as confirmed by linear-thermal-expansion measurements. The Curie temperature TC remains essentially unchanged for Mn contents up to x=1 [TC=370(4) K for x=0.0, TC=373(4) …
Magnetic Properties And Magnetocaloric Effect Of (Mn1-Xnix)3sn2(X=0-0.5) Compounds, Rong Zeng, Lin Lu, Jung Ho Kim, Dongqi Shi, Hua-Kun Liu, S. X. Dou, Jianli Wang, Stewart J. Campbell, Zhaoxiang Wang, Y Li, Wenxian Li, M Y. Zhu, Chuanqi Feng
Magnetic Properties And Magnetocaloric Effect Of (Mn1-Xnix)3sn2(X=0-0.5) Compounds, Rong Zeng, Lin Lu, Jung Ho Kim, Dongqi Shi, Hua-Kun Liu, S. X. Dou, Jianli Wang, Stewart J. Campbell, Zhaoxiang Wang, Y Li, Wenxian Li, M Y. Zhu, Chuanqi Feng
Jianli Wang
The effects of Ni substitution on the magnetic properties and magnetocaloric effect (MCE) of (Mn1−xNix)3Sn2 compounds (x = 0–0.5) have been investigated by x-ray diffraction and magnetization measurements. It was found that Ni substitution decreases the crystal cell volume and the magnetic transition temperatures compared with pure Mn3Sn2. The MCE for all samples has been calculated from the magnetization data in terms of the isothermal magnetic entropy change ΔSM. The maximum values of ΔSMmax at the magnetic phase transition temperatures resulting from a change in magnetic field of ΔH = 5 T were found to be 28.2 mJ/cm3 K for …
Structural Properties And Magnetic Phase Transition In Honi2mn (57fe), Jianli Wang, Stewart J. Campbell, M Hofmann, M Hoelzel, Rong Zeng, S. X. Dou, S J. Kennedy
Structural Properties And Magnetic Phase Transition In Honi2mn (57fe), Jianli Wang, Stewart J. Campbell, M Hofmann, M Hoelzel, Rong Zeng, S. X. Dou, S J. Kennedy
Jianli Wang
"The structural and magnetic properties of HoNi2Mn (57Fe) have been investigated.The Fe-57-doped HoNi2Mn compound crystallizes in the MgCu2-type structure with Fd-3m space group similar to HoNi2 and HoMn2.HoNi2Mn (57Fe) exhibits ferrimagnetic ordering below a Curie temperature of T-C similar to 60 K-significantly higher than the corresponding values for HoNi2 (T-C - 15 K) and HoMn2 (T-C 24 K)-with analyses of dc magnetization and ac susceptibility results confirming that the magnetic transition at T-C is second order.The Mossbauer spectra above T-C are described well by two sub-spectra representing the 8a and 16d sites while below T-C the spectra have been fitted …
Temperature-Dependent Electrical, Elastic And Magnetic Properties Of Solgel Synthesized Bi 0.9ln 0.1feo 3 (Ln=Nd,Sm), J Schiemer, R L Withers, M Carpenter, Y Liu, Jianli Wang, L Noren, Q Li, W Hutchison
Temperature-Dependent Electrical, Elastic And Magnetic Properties Of Solgel Synthesized Bi 0.9ln 0.1feo 3 (Ln=Nd,Sm), J Schiemer, R L Withers, M Carpenter, Y Liu, Jianli Wang, L Noren, Q Li, W Hutchison
Jianli Wang
This report details correlated electrical, mechanical and magnetic behaviour in BiFeO3 ceramics doped with 10% Ln (Ln D Sm, Nd) ions on the Bi, or perovskite A, site and synthesized by a sol-gel method. The ceramics exhibit bulk piezoelectric and ferroelectric properties and clear ferroelectric domain patterns through piezoresponse force microscopy. Resonant ultrasound spectroscopy, dielectric spectroscopy and magnetometry studies show correlated magnetoelectromechanical behaviour and the existence of weak ferromagnetism for both compositions. An anomaly with simultaneous mechanical and magnetic signatures is discovered in both materials near room temperature, while previously reported transitions and anomalies are found to exhibit electro- and/or …
Magnetic Properties Of Bi2femno6: A Multiferroic Material With Double-Perovskite Structure, Yi Du, Zhenxiang Cheng, S X. Dou, Xiaolin Wang, Hua Zhao, Hideo Kimura
Magnetic Properties Of Bi2femno6: A Multiferroic Material With Double-Perovskite Structure, Yi Du, Zhenxiang Cheng, S X. Dou, Xiaolin Wang, Hua Zhao, Hideo Kimura
Shi Xue Dou
Single phase Bi2FeMnO6 was synthesized on Si substrates by an electrospray method. Three peaks were observed in the temperature dependence of magnetization curve, which is attributed to the inhomogeneous distribution of Fe3+ and Mn3+. The observed magnetic peaks at 150 K, 260 K, and 440 K correspond to orderings of the ferrimagnetic Fe–O–Mn, and antiferromagnetic Mn–O–Mn and Fe–O–Fe, respectively. Heat capacity measurements were carried out to confirm these magnetic transitions. The Debye temperature of Bi2FeMnO6 is 339 K, calculated from Debye–Einstein fitting.
A Significant Improvement In The Superconducting Properties Of Mgb2 By Co-Doping With Graphene And Nano-Sic, K S B De Silva, X Xu, Xiaolin Wang, D Wexler, D Attard, F Xiang, S. X. Dou
A Significant Improvement In The Superconducting Properties Of Mgb2 By Co-Doping With Graphene And Nano-Sic, K S B De Silva, X Xu, Xiaolin Wang, D Wexler, D Attard, F Xiang, S. X. Dou
Shi Xue Dou
The effects of graphene (G) and nanosilicon carbide (SiC) co-doping on the superconducting properties of MgB2 were studied using bulk samples. SiC remains one of the best dopants which can significantly improve the high field performance, while graphene is emerging as a new dopant for MgB2, which can improve the zero field critical current density (Jc). The superconducting properties characterized by Jc, the intergrain connectivity, and the critical fields were significantly improved by the use of both SiC and graphene as dopants.
Anisotropic And Excellent Magnetocaloric Properties Of La 0.7ca0.3mno3 Single Crystal With Anomalous Magnetization, J.C Debnath, Rong Zeng, Jung Ho Kim, Dapeng Chen, S X. Dou
Anisotropic And Excellent Magnetocaloric Properties Of La 0.7ca0.3mno3 Single Crystal With Anomalous Magnetization, J.C Debnath, Rong Zeng, Jung Ho Kim, Dapeng Chen, S X. Dou
Shi Xue Dou
Magnetic properties and the magnetocaloric effect (MCE) have been investigated in La0.7Ca0.3MnO3 single crystal with applied field along both the ab-plane and the c-direction. Due to the magnetocrystalline anisotropy, the crystal exhibits anisotropy in the MCE. Upon application of a 5 T field, the magnetic entropy changes (SM), reaching values of 7.668 J/(kg K) and 6.412 J/(kg K) for both the ab-plane and the c-direction, respectively. A magnetic entropy change of 3.3 J/(kg K) was achieved for a magnetic field change of 1.5 T at the Curie temperature, TC = 245 K. Due to the absence of grains in the …
Lanthanum Doped Multiferroic Dyfeo3: Structural And Magnetic Properties, Yi Du, Zhenxiang Cheng, Xiaolin Wang, S X. Dou
Lanthanum Doped Multiferroic Dyfeo3: Structural And Magnetic Properties, Yi Du, Zhenxiang Cheng, Xiaolin Wang, S X. Dou
Shi Xue Dou
Lanthanum doped multiferroic DyFeO3 was synthesized by solid state reaction. X-ray diffraction and refinement show that the lattice parameters of Dy1−xLaxFeO3 increase linearly with the La content. Raman spectroscopy reveals that the short-range force constant in Dy1−xLaxFeO3 is decreased by La3+ ion substitution. The spin reorientation phase transition temperature (TSRPT) is observed to decrease along with the doping level. The antiferromagnetic ordering temperature TN of Fe3+ ions is depressed with increasing doping level. Both decreasing TSRPT and decreasing TN indicate that Fe–Dy and Fe–Fe interactions are weakened by La substitution. It is found that the electron configuration of Fe3+ is …
The Effects Of Size And Orientation On Magnetic Properties And Exchange Bias In Co3o4 Mesoporous Nanowires, Rong Zeng, J Q Wang, Zhixin Chen, Wenxian Li, S. X. Dou
The Effects Of Size And Orientation On Magnetic Properties And Exchange Bias In Co3o4 Mesoporous Nanowires, Rong Zeng, J Q Wang, Zhixin Chen, Wenxian Li, S. X. Dou
Shi Xue Dou
Co3O4 mesoporous nanowires with average single crystalline grain sizes of about 8 nm, 12nm, 25 nm, and 45 nm were synthesized by sintering of microwave-assisted hydrothermal processed belt-Co(OH)2 precursors at 300–500 °C for 2 h. Microstructure analysis was conducted by x-ray diffraction, x-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), field emission SEM (FESEM), transmission electron microscopy (TEM), and high resolution TEM (HRTEM) to confirm the composition, structure, and orientation in the nanowires. Systematic magnetic measurements have also been conducted on the nanowires. It was found that the size and orientation have significant effects on the magnetic and exchange …
The Mechanical And The Electrical Properties Of Conducting Polypyrrole Fibers, Javad Foroughi, Shaban R. Ghorbani, Germanas Peleckis, Geoffrey M. Spinks, Gordon G. Wallace, Xiaolin Wang, S X. Dou
The Mechanical And The Electrical Properties Of Conducting Polypyrrole Fibers, Javad Foroughi, Shaban R. Ghorbani, Germanas Peleckis, Geoffrey M. Spinks, Gordon G. Wallace, Xiaolin Wang, S X. Dou
Shi Xue Dou
The mechanical and the electrical properties of polypyrrole (PPy) fibers and electrochemically deposited PPy films were studied. It was found that the PPy fibers showed a significantly higher strength than the PPy films due to better orientation of the molecular structure. The electrochemically prepared PPy films had a higher electrical conductivity than that of the fibers at high temperature. At low temperature, the PPy fibers showed the higher conductivity. The conductivity results were analyzed in the frame of the three-dimensional variable range hopping model. The results showed that at room temperature the average hopping distance for the fibers was about …
Benzoic Acid Doping To Enhance Electromagnetic Properties Of Mgb2 Superconductors, W. X. Li, Y. Li, M. Y. Zhu, R. H. Chen, X. Xu, W. K. Yeoh, J. H. Kim, S. X. Dou
Benzoic Acid Doping To Enhance Electromagnetic Properties Of Mgb2 Superconductors, W. X. Li, Y. Li, M. Y. Zhu, R. H. Chen, X. Xu, W. K. Yeoh, J. H. Kim, S. X. Dou
Shi Xue Dou
The effect of benzoic acid doping on lattice parameters, microstructure, critical temperature (T-c), critical current density (J(c)) and flux pinning force of MgB2 has been studied. In this work we used benzoic acid as an example of aromatic acids as an additive to MgB2. For different sintering process, actual carbon (C) substitution for boron (B) was estimated to be from 3.5 at% to 5.0 at% of B while T-c dropped about 2-4 K. The advantages of aromatic acid doping include homogeneous mixing of precursor powders, avoidance of expansive nano-additives, production of highly reactive C and significant enhancement in J(c) of …
Fabrication, Magnetic, And Ferroelectric Properties Of Multiferroic Bifeo3 Hollow Nanoparticles, Yi Du, Zhenxiang Cheng, S X. Dou, Darren J. Attard, Xiaolin Wang
Fabrication, Magnetic, And Ferroelectric Properties Of Multiferroic Bifeo3 Hollow Nanoparticles, Yi Du, Zhenxiang Cheng, S X. Dou, Darren J. Attard, Xiaolin Wang
Shi Xue Dou
Hollow BiFeO3 nanoparticles were synthesized by an electrospray route for the first time. The phase purity and structure have been investigated by x-ray diffraction and Raman spectroscopy. Transmission and scanning electron microscope investigations revealed that the as-obtained BiFeO3 hollow spheres were polycrystalline, with a shell thickness of 35 nm. The formation mechanism can be possibly explained by Ostwald ripening. Raman spectra have verified decreased vibrational frequencies in BiFeO3 nanoparticles. These hollow and core-shell multiferroic nanoparticles exhibit significantly enhanced ferromagnetism from 5 to 600 K due to a broken spiral spin structure. The ferroelectricity of hollow BiFeO3 particles exhibits a lower …
Magnetic And Superconducting Properties Of Spin-Fluctuation-Limited Superconducting Nanoscale Vnx, R Zeng, J Liu, G Du, W. X. Li, J Wang, J Horvat, S X. Dou
Magnetic And Superconducting Properties Of Spin-Fluctuation-Limited Superconducting Nanoscale Vnx, R Zeng, J Liu, G Du, W. X. Li, J Wang, J Horvat, S X. Dou
Shi Xue Dou
"VNx nanoparticles and nanowires have been prepared by nitrifying V2O5 nanoparticles (NP) and nanowires (NW). The V2O5 NP and NW were synthesized by a facile hydrothermal method. Magnetic susceptibility (chi) and magnetization measurements showed long range superconducting ordering (LRSO) at the temperature of 5.8 K for NW, but there was no observation of LRSO (at least down to 2 K) for the NP sample, which is a much lower temperature than for the corresponding bulk, while both NP and NW showed the absence of long range magnetic ordering, at least down to 2 K. However, the chi data showed that …
Superconducting Properties Of Carbonaceous Chemical Doped Mgb2, Wenxian Li, S X. Dou
Superconducting Properties Of Carbonaceous Chemical Doped Mgb2, Wenxian Li, S X. Dou
Shi Xue Dou
The discovery of superconductivity in magnesium diboride (MgB2: 39 K, in January 2001) (Nagamatsu et al., 2001) has generated enormous interest and excitement in the superconductivity community and the world in general, but especially among researchers into superconductivity in non-oxide and boron related compounds.
Single-Crystal Growth And Anisotropic Magnetic Properties Of Nonstoichiometric Three-Layer Sodium Cobalt Oxides, Dapeng Chen, Xiaolin Wang, C T Lin, S X. Dou
Single-Crystal Growth And Anisotropic Magnetic Properties Of Nonstoichiometric Three-Layer Sodium Cobalt Oxides, Dapeng Chen, Xiaolin Wang, C T Lin, S X. Dou
Shi Xue Dou
Large single crystals of α-NaxCoO2 (x=0.91, 0.92, and 0.93) have been successfully fabricated by using the traveling solvent floating zone method. Details on the crystal growth are discussed. The crystal structures were characterized using powder x-ray diffraction and Rietveld refinement. The magnetic susceptibility measurements show that the magnetic properties depend strongly on x. The compound was found to be antiferromagnetic at TN ≈ 20 K for x=0.91 and x=0.92, and paramagnetic for x=0.93. The in-plane and out-of-plane anisotropies were observed for the x=0.91 crystals. In addition, the derived anisotropic g-factor ratios (gab /gc) from the anisotropic susceptibility along H||ab and …
Phase Transformation And Superconducting Properties Of Mgb2 Using Ball-Milled Low Purity Boron, Xun Xu, Jung Ho Kim, Md. Shahriar-Al Hossain, Jinsoo Park, Yue Zhao, S. X. Dou, Wai Kong Yeoh, M Rindfleisch, M Tomsic
Phase Transformation And Superconducting Properties Of Mgb2 Using Ball-Milled Low Purity Boron, Xun Xu, Jung Ho Kim, Md. Shahriar-Al Hossain, Jinsoo Park, Yue Zhao, S. X. Dou, Wai Kong Yeoh, M Rindfleisch, M Tomsic
Shi Xue Dou
MgB2 samples were prepared by using 96% boron (B) powder with strong crystalline phase that had been ball milled for various times. We observed samples that contained ball-milled 96% B in comparison with one made from as-supplied commercial 96% B, with the results showing a significant enhancement in the high field critical current density (Jc) due to small grain size and better reactivity. Specifically, many grain boundaries for MgB2 could be acting as strong flux pinning centers. Based on Rowell connectivity analysis, when the ball-milling time increased, the connectivity factor, described as the active cross-sectional area fraction (AF), was decreased. …
"Density Of States, Magnetic And Transport Properties Of Nd Doped Two Dimensional Perovskite Compound Sr2coo4", Qiwen Yao, Hideo Kimura, Xiaolin Wang, Kosta Konstantinov, Hongyang Zhao, Hai Qiu, Rumi Tanahashi, Kiyoshi Ozawa, S. X. Dou
"Density Of States, Magnetic And Transport Properties Of Nd Doped Two Dimensional Perovskite Compound Sr2coo4", Qiwen Yao, Hideo Kimura, Xiaolin Wang, Kosta Konstantinov, Hongyang Zhao, Hai Qiu, Rumi Tanahashi, Kiyoshi Ozawa, S. X. Dou
Shi Xue Dou
"Structures, transport, magnetic properties, and first principle calculation results will be reported for the two dimensional layered structured perovskite compounds Sr2-xNdxCoO4 (x = 0.5, 0.75, 1, 1.25). Structure refinement results revealed that these compounds crystallized in K2NiF4-type structures with space group I4/mmm. The temperature dependence of resistivity showed semiconductor like behavior for these samples. It was found that the lattice parameter c decreases as the doping level x increases. The compounds exhibited a paramagnetic to ferromagnetic transition at temperatures of about 170, 125 K for the x = 1 and 0.75 samples, respectively. The temperature dependence of resistivity for the …
Mechanism Of Enhancement In Electromagnetic Properties Of Mgb2 By Nano Sic Doping, S X. Dou, Olga V. Shcherbakova, W. K. Yeoh, J. H. Kim, Saeid Soltanian, Xiaolin Wang, C. Senatore, R. Flukiger, M. Dhalle, O. Husnjak, E. Babic
Mechanism Of Enhancement In Electromagnetic Properties Of Mgb2 By Nano Sic Doping, S X. Dou, Olga V. Shcherbakova, W. K. Yeoh, J. H. Kim, Saeid Soltanian, Xiaolin Wang, C. Senatore, R. Flukiger, M. Dhalle, O. Husnjak, E. Babic
Shi Xue Dou
A comparative study of pure, SiC, and C doped MgB2 wires has revealed that the SiC doping allowed C substitution and MgB2 formation to take place simultaneously at low temperatures. C substitution enhances Hc2, while the defects, small grain size, and nanoinclusions induced by C incorporation and low-temperature processing are responsible for the improvement in Jc. The irreversibility field (Hirr) for the SiC doped sample reached the benchmarking value of 10 T at 20 K, exceeding that of NbTi at 4.2 K. This dual reaction model also enables us to predict desirable dopants for enhancing the performance properties of MgB2.