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"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
Faculty of Engineering - Papers (Archive)
"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 …
Terahertz Magnetic Field Induced Coherent Spin Precession In Yfeo3, Runze Zhou, Zuanming Jin, Gaofang Li, Guohong Ma, Zhenxiang Cheng, Xiaolin Wang
Terahertz Magnetic Field Induced Coherent Spin Precession In Yfeo3, Runze Zhou, Zuanming Jin, Gaofang Li, Guohong Ma, Zhenxiang Cheng, Xiaolin Wang
Faculty of Engineering - Papers (Archive)
We present the magnetic dipole transition at 0.299 THz excited by magnetic component of terahertz electromagnetic pulse in an antiferromagnetic YFeO3 crystal. The impulsive magnetic field of the terahertz pulse tilts the macroscopic magnetization, causing deviation from the equilibrium position, which is manifested by a sharp absorption at the frequency of the quasiferromagnetic mode of the crystal. The rotating coherent macroscopic magnetization radiates elliptically polarized emission at the frequency of the quasiferromagnetic resonance due to the dichroic absorption in the crystal.
Spatial Dispersion Management In Three-Dimensional Drawn Magnetic Metamaterials, Alessandro Tuniz, Benjamin Pope, Alexander Argyros, Simon Fleming, Anna Wang, Maryanne C. J Large, Elise M. Pogson, Roger A. Lewis, Avi Bendavid, Boris T. Kuhlmey
Spatial Dispersion Management In Three-Dimensional Drawn Magnetic Metamaterials, Alessandro Tuniz, Benjamin Pope, Alexander Argyros, Simon Fleming, Anna Wang, Maryanne C. J Large, Elise M. Pogson, Roger A. Lewis, Avi Bendavid, Boris T. Kuhlmey
Faculty of Engineering - Papers (Archive)
We characterize resonances of 3D fiber metamaterials under transmittance at oblique incidence. The resonance frequency of longitudinally invariant resonators increases with the incident angle, while the resonance of disconnected resonators does not. © 2012 OSA.
Effect Of A Static Magnetic Field On Nanodosimetric Quantities In A Dna Volume, Peter Lazarakis, Marion U. Bug, Elisabetta Gargioni, Susanna Guatelli, Sabastien Incerti, Hans Rabus, Anatoly B. Rosenfeld
Effect Of A Static Magnetic Field On Nanodosimetric Quantities In A Dna Volume, Peter Lazarakis, Marion U. Bug, Elisabetta Gargioni, Susanna Guatelli, Sabastien Incerti, Hans Rabus, Anatoly B. Rosenfeld
Faculty of Engineering - Papers (Archive)
Abstract Purpose: With the advent of magnetic resonance imaging (MRI)-guided radiation therapy it is becoming increasingly important to consider the potential influence of a magnetic field on ionising radiation. This paper aims to study the effect of a magnetic field on the track structure of radiation to determine if the biological effectiveness may be altered. Methods: Using the Geant4-DNA (GEometry ANd Tracking 4) Monte Carlo simulation toolkit, nanodosimetric track structure parameters were calculated for electrons, protons and alpha particles moving in transverse magnetic fields up to 10 Tesla. Applying the model proposed by Garty et al., the track structure parameters …
Abnormal Magnetic Behaviors And Large Magnetocaloric Effect In Mnps3 Nanoparticles, R Zeng, S Q. Wang, G D. Du, Jianli Wang, J C. Debnath, Precious Shamba, Z Y. Fang, S. X. Dou
Abnormal Magnetic Behaviors And Large Magnetocaloric Effect In Mnps3 Nanoparticles, R Zeng, S Q. Wang, G D. Du, Jianli Wang, J C. Debnath, Precious Shamba, Z Y. Fang, S. X. Dou
Faculty of Engineering - Papers (Archive)
A nanostructured honeycomb lattice consisting of MnPS3 nanoparticles synthesized via the ion-exchange technique was found to have restacked molecular layers stabilized by H2O insertion between the layers. Susceptibility (χ) and heat capacity measurements showed the absence of long range magnetic ordering, at least down to 2 K. However, the χ data showed that the system possesses a high effective Curie temperature, suggesting that the system is in a high spin lattice disordered state. Evaluation of the magnetocaloric effect indicates that the system has a large reversible magnetic-entropy change (−ΔSm) of 6.8 and 12.8 J/kg K …
Spatial Dispersion In Three-Dimensional Drawn Magnetic Metamaterials, Alessandro Tuniz, Benjamin Pope, Anna Wang, Maryanne C. J Large, Shaghik Atakaramians, Seong-Sik Min, Elise M. Pogson, Roger A. Lewis, Avi Bendavid, Alexander Argyros, Simon C. Fleming, Boris T. Kuhlmey
Spatial Dispersion In Three-Dimensional Drawn Magnetic Metamaterials, Alessandro Tuniz, Benjamin Pope, Anna Wang, Maryanne C. J Large, Shaghik Atakaramians, Seong-Sik Min, Elise M. Pogson, Roger A. Lewis, Avi Bendavid, Alexander Argyros, Simon C. Fleming, Boris T. Kuhlmey
Faculty of Engineering - Papers (Archive)
We characterize spatial dispersion in longitudinally invariant drawn metamaterials with a magnetic response at terahertz frequencies, whereby a change in the angle of the incident field produces a shift in the resonant frequency. We present a simple analytical model to predict this shift. We also demonstrate that the spatial dispersion is eliminated by breaking the longitudinal invariance using laser ablation. The experimental results are in agreement with numerical simulations.
Growth Mechanism And Magnetic Properties Of Highly Crystalline Nio Nanocubes And Nanorods Fabricated By Evaporation, Dapeng Chen, Xiaolin Wang, Yi Du, Song Ni, Zi-Bin Chen, Xiaozhou Liao
Growth Mechanism And Magnetic Properties Of Highly Crystalline Nio Nanocubes And Nanorods Fabricated By Evaporation, Dapeng Chen, Xiaolin Wang, Yi Du, Song Ni, Zi-Bin Chen, Xiaozhou Liao
Faculty of Engineering - Papers (Archive)
A new approach to the preparation of regularly shaped NiO nanocubes and nanorods by an infrared heating evaporation method is presented. The growth model is proposed to be a vapor−solid mechanism. The morphology of the nanocrystals can be tuned by the carrier gas flow rate. The samples consist of nanocrystals that are highly crystallized with atomic-scale smooth surfaces. This novel method could be extended to nanocrystal growth of other oxides with low volatility or high melting points. The results of magnetic characterization indicate that the NiO nanorods and nanocubes grown from a mixed target both show weak ferromagnetic states at …
"Oxygen-Vacancy Effect On Structural, Magnetic, And Ferroelectric Properties In Multiferroic Ymno3 Single Crystals", Dapeng Chen, Yi Du, Xiaolin Wang, Zhenxiang Cheng, S. X. Dou, Zhi W. Lin, Jian G. Zhu, Bo Xu
"Oxygen-Vacancy Effect On Structural, Magnetic, And Ferroelectric Properties In Multiferroic Ymno3 Single Crystals", Dapeng Chen, Yi Du, Xiaolin Wang, Zhenxiang Cheng, S. X. Dou, Zhi W. Lin, Jian G. Zhu, Bo Xu
Faculty of Engineering - Papers (Archive)
"We have investigated the structural, magnetic, and ferroelectric properties of magnetically frustrated multiferroic YMnO3 single crystals. The ferroelectric domain structures of YMnO3 samples were studied by piezoresponse force microscopy. Instead of domain vortex structure in stoichiometric crystals, YMnO3-delta exhibits a random domain configuration with straight domain walls. In magnetic measurements, the YMnO3-delta crystal shows typical antiferromagnetic behavior with higher Neel temperature and lower magnetization compared to the stoichiometric sample. The ordered oxygen vacancies dominate multiferroicity through tailoring the domain wall structure. (C) 2012 American Institute of Physics. [doi:10.1063/1.3676000]"
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
Faculty of Engineering - Papers (Archive)
"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 …
Infrared Phonon Anomaly And Magnetic Excitations In Single-Crystal Cu3bi(Seo3)2o2cl, K H. Miller, P W. Stephens, C Martin, E Constable, R A. Lewis, H Berger, G L. Carr, D B. Tanner
Infrared Phonon Anomaly And Magnetic Excitations In Single-Crystal Cu3bi(Seo3)2o2cl, K H. Miller, P W. Stephens, C Martin, E Constable, R A. Lewis, H Berger, G L. Carr, D B. Tanner
Faculty of Engineering - Papers (Archive)
nfrared reflection and transmission as a function of temperature have been measured on single crystals of Cu3Bi(SeO3)2O2Cl. The complex dielectric function and optical properties along all three principal axes of the orthorhombic cell were obtained via Kramers-Kronig analysis and by fits to a Drude-Lorentz model. Below 115 K, 16 additional modes [8(E∥â)+6(E∥b̂)+2(E∥ĉ)] appear in the phonon spectra; however, powder x-ray diffraction measurements do not detect a new structure at 85 K. Potential explanations for the new phonon modes are discussed. Transmission in the far infrared as a function of temperature has revealed …
Magnetic Propulsion Of A Spiral-Type Endoscopic Microrobot In A Real Small Intestine, Hao Zhou, Gursel Alici, Trung Duc Than, Weihua Li, Sylvain Martel
Magnetic Propulsion Of A Spiral-Type Endoscopic Microrobot In A Real Small Intestine, Hao Zhou, Gursel Alici, Trung Duc Than, Weihua Li, Sylvain Martel
Faculty of Engineering - Papers (Archive)
This paper reports on the magnetic propulsion of a spiral-type endoscopic mircorobot in a real small intestine. Magnetic modeling was carried out to design and commission an external electromagnetic system, which wirelessly provides power to the robotic agent. The capsules with different spiral structures were magnetically propelled inside a segment of porcine small intestine. From the results, it is shown that the propulsive velocities of the tested capsules are in the range of 2.5 ~ 35 mm/s when rotating frequencies varying between 1 ~ 5 Hz are applied. Among all the capsules prepared for this study, the capsule No. 5, …
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
Faculty of Engineering - Papers (Archive)
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 …
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
Faculty of Engineering - Papers (Archive)
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 …
Magnetoresistance, Critical Current Density, And Magnetic Flux Pinning Mechanism In Nickel Doped Bafe2as2 Single Crystals, Mahboobeh Shahbazi, Xiaolin Wang, Z W. Lin, J G. Zhu, S. X. Dou, K Y. Choi
Magnetoresistance, Critical Current Density, And Magnetic Flux Pinning Mechanism In Nickel Doped Bafe2as2 Single Crystals, Mahboobeh Shahbazi, Xiaolin Wang, Z W. Lin, J G. Zhu, S. X. Dou, K Y. Choi
Faculty of Engineering - Papers (Archive)
The critical current density, Jc, flux pinning behavior and magneto- resistance results of BaFe2-xNixAs2 single crystal have been investigated in fields up to 13 T over a temperature range of 2 to 20 K. The magnetoresistance below the superconducting transition temperature (Tc) shows Arrhenius thermally activated behavior: ρ = ρoexp(-Uo(T,H)/kBT), where Uo is the thermally activated energy. BaFe2-xNixAs2 exhibits high thermally activated flux flow energy with a very weak …
Reduction Of Hysteresis Losses In The Magnetic Refrigerant La0.8ce0.2fe11.4si1.6 By The Addition Of Boron, Precious Shamba, J.C Debnath, Rong Zeng, Jianli Wang, Stewart J. Campbell, S J. Kennedy, S. X. Dou
Reduction Of Hysteresis Losses In The Magnetic Refrigerant La0.8ce0.2fe11.4si1.6 By The Addition Of Boron, Precious Shamba, J.C Debnath, Rong Zeng, Jianli Wang, Stewart J. Campbell, S J. Kennedy, S. X. Dou
Faculty of Engineering - Papers (Archive)
In an effort to improve the magnetocaloric effects of the NaZn13-type La0.8Ce0.2Fe11.4Si1.6 compound, the effect of boron doping on the magnetic properties and magnetocaloric properties has been investigated. The magnetic entropy change (ΔSM) for the La0.8Ce0.2Fe11.4Si1.6 compound, obtained for a field change of 0–5 T using the Maxwell relation exhibits a spike and appears to be overestimated and is thus corrected by using the Clausius-Clapeyron equation (CC). The ΔSM determined from the CC equation is estimated to be 19.6 J kg …
Magnetic And Ferroelectric Properties Of Multiferroic Bi2nimno6 Nanoparticles, Yi Du, Zhenxiang Cheng, Xiaolin Wang, Peng Liu, S. X. Dou
Magnetic And Ferroelectric Properties Of Multiferroic Bi2nimno6 Nanoparticles, Yi Du, Zhenxiang Cheng, Xiaolin Wang, Peng Liu, S. X. Dou
Faculty of Engineering - Papers (Archive)
Multiferroic Bi2NiMnO6 nanoparticles were synthesized by a simple electrospray method. Bi2NiMnO6 nanoparticles crystallize in the monoclinic structure with space group C121. The particles show a uniform spherical shape with a diameter of 100 nm to 300 nm. The ferromagnetic transition of Bi2NiMnO6 is confirmed at 122 K. The room temperature ferroelectricity of the Bi2NiMnO6 nanoparticles is verified by Kelvin probe force microscopy.
Continuously Tunable Magnetic Phase Transitions In The Dymn1-Xfexo3 System, Fang Hong, Zhenxiang Cheng, Hongyang Zhao, Hideo Kimura, Xiaolin Wang
Continuously Tunable Magnetic Phase Transitions In The Dymn1-Xfexo3 System, Fang Hong, Zhenxiang Cheng, Hongyang Zhao, Hideo Kimura, Xiaolin Wang
Faculty of Engineering - Papers (Archive)
The structure and magnetic properties of perovskite DyMn1−xFexO3 samples have been studied. Static orbital orderings are expected to exist in samples with x ≤ 0.2 due to strong Jahn-Teller distortion, which become less stable as x increases and probably disappears in samples with x > 0.5. The antiferromagnetic transition temperature increases as x increases. At the composition x > 0.5, spin reorientation starts to appear. Meanwhile, the spin reorientation temperature and the antiferromagnetic Néel temperature gradually separate and widen the temperature range of the magnetic metastable state between these two transitions. The magnetic competition is discussed based …
Giant Magnetic Flux Jumps In Single Crystals Of Ba0.6k0.4fe2as2, Ki-Young Choi, Gun Sang Jeon, X.F Wang, X.H Chen, Xiaolin Wang, Myung-Hwa Jung, Sung-Ik Lee, Gangseo Park
Giant Magnetic Flux Jumps In Single Crystals Of Ba0.6k0.4fe2as2, Ki-Young Choi, Gun Sang Jeon, X.F Wang, X.H Chen, Xiaolin Wang, Myung-Hwa Jung, Sung-Ik Lee, Gangseo Park
Faculty of Engineering - Papers (Archive)
Giant magnetic flux jumps are observed in magnetic hysteresis loops of Ba0.6K0.4Fe2As2 single crystals. The size of the flux jumps, which appear only at low temperatures (T<4 >K), is so large that it can transform the whole superconducting state into the normal state. The recovery rate to the superconducting state is rather slow, although the superconducting state is almost fully recovered. We show that theoretical predictions based on the adiabatic approach with nonlocal electrodynamics give a good explanation of the flux jumps observed in the single crystals of Ba0.6K0.4 …
Neutron Diffraction Study Of The Magnetic Order In Ndmn2ge1.6si0.4, Jianli Wang, Stewart J. Campbell, John M. Cadogan, A J Studer, Rong Zeng, S. X. Dou
Neutron Diffraction Study Of The Magnetic Order In Ndmn2ge1.6si0.4, Jianli Wang, Stewart J. Campbell, John M. Cadogan, A J Studer, Rong Zeng, S. X. Dou
Faculty of Engineering - Papers (Archive)
Here we report a detailed investigation of NdMn2Ge1.6Si0.4; this forms part of our investigation of the magnetic order across the NdMn2Ge2−xSix (x = 0–2.0) series by magnetometry, x-ray diffraction and neutron diffraction over the temperature range 6–465 K. On decreasing the temperature from 465 K, NdMn2Ge1.6Si0.4 exhibits four magnetic transitions: (i) from paramagnetism to intralayer antiferromagnetism AFl at TIntraN ~ 430 K; (ii) AFl to canted ferromagnetism Fmc at TInterC ~ 330 K; (iii) Fmc to conical magnetic ordering …
Fiber Metamaterials With Negative Magnetic Permeability In The Terahertz, Anna Wang, Alessandro Tuniz, Peter Hunt, Elise Pogson, R A. Lewis, Avi Bendavid, Simon Fleming, Boris Kuhlmey, Maryanne Large
Fiber Metamaterials With Negative Magnetic Permeability In The Terahertz, Anna Wang, Alessandro Tuniz, Peter Hunt, Elise Pogson, R A. Lewis, Avi Bendavid, Simon Fleming, Boris Kuhlmey, Maryanne Large
Faculty of Engineering - Papers (Archive)
We present a novel method for producing metamaterials with a terahertz magnetic response via fiber drawing, which can be inexpensively scaled up to mass production. We draw a centimeter preform to fiber, spool it, and partially sputter it with metal to produce extended slotted resonators. We characterize metamaterial fiber arrays with different orientations via terahertz time domain spectroscopy, observing distinct magnetic resonances between 0.3 and 0.4 THz, in excellent agreement with simulations. Numerical parameters retrieval techniques confirm that such metamaterials possess negative magnetic permeability. Combined with fiber-based negative permittivity materials, this will enable the development of the first woven negative …
Effects Of Cu And Fe Doping On Raman Spectra And On The Structural And Magnetic Properties Of Ermno3, Peng Liu, Zhenxiang Cheng, Yi Du, Xiaolin Wang
Effects Of Cu And Fe Doping On Raman Spectra And On The Structural And Magnetic Properties Of Ermno3, Peng Liu, Zhenxiang Cheng, Yi Du, Xiaolin Wang
Faculty of Engineering - Papers (Archive)
Single phase ErMexMn1−xO3 (Me = Cu, Fe; 0 ≤ x ≤ 0.1) samples were synthesized by the solid state reaction method. The differences between the doping effects on the Raman spectra and on the structural, magnetic, and thermal properties of the two systems have been systematically investigated. In the ErCuxMn1−xO3 system, lattice parameter a increases with doping, while lattice parameter c decreases. It is more complicated in the ErFexMn1−xO3 system, where lattice parameter a decreases with doping, while lattice parameter c is enhanced after an …
Magnetic Phase Transition And Mossbauer Spectroscopy Of Erni2mnx Compounds, Jianli Wang, S J. Campbell, R Zeng, S. X. Dou, S J. Kennedy
Magnetic Phase Transition And Mossbauer Spectroscopy Of Erni2mnx Compounds, Jianli Wang, S J. Campbell, R Zeng, S. X. Dou, S J. Kennedy
Faculty of Engineering - Papers (Archive)
Investigation of ErNi2Mnx with 0.90 ≤ x ≤ 1.10 indicates that the MgCu2-type structure (with space group Fd-3m) is formed within x = 0.97−1.10. Curie temperature TC = 50 K of ErNi2Mn is significantly higher than those of the corresponding ErNi2 (TC = 7 K) and ErMn2 (TC = 15 K) compounds. Detailed analyses of DC magnetization data demonstrate that the magnetic phase transition at the Curie temperature is second order. The magnetic entropy change around TC has been found to be 4.8 J/kg K for …
Robust High-Temperature Magnetic Pinning Induced By Proximity In Yba2cu3o7-8/La0.67sr0.33mno3 Hybrids, C.Z Chen, Z Y. Liu, Y M. Lu, L Zeng, C B. Cai, Rong Zeng, S. X. Dou
Robust High-Temperature Magnetic Pinning Induced By Proximity In Yba2cu3o7-8/La0.67sr0.33mno3 Hybrids, C.Z Chen, Z Y. Liu, Y M. Lu, L Zeng, C B. Cai, Rong Zeng, S. X. Dou
Faculty of Engineering - Papers (Archive)
An elaborately designed bilayer consisting of superconducting YBa2Cu3O7-6 (YBCO) and ferromagnetic La0.67Sr0.33MnO3-6 (LSMO) was prepared on a single crystal LaAlO3 substrate by pulsed laser deposition (PLD), with a view to understanding the mechanism behind the influence of superconductor/ferromagnet proximity on the critical current density, Jc. The present bilayer system shows significant modifications in Jc, as evidenced by the suppressed decay of its temperature dependence, as well as the crossing behavior of the magnetic field dependence of Jc at high temperatures. This indicates that enhanced …
Critical Magnetic Transition In Tbni2mn-Magnetization And Mossbauer Spectroscopy, Jianli Wang, S J. Campbell, S J. Kennedy, Rong Zeng, S. X. Dou, Guangheng Wu
Critical Magnetic Transition In Tbni2mn-Magnetization And Mossbauer Spectroscopy, Jianli Wang, S J. Campbell, S J. Kennedy, Rong Zeng, S. X. Dou, Guangheng Wu
Faculty of Engineering - Papers (Archive)
The structural and magnetic properties of the TbNi2Mnx series (0.9 ≤ x ≤ 1.10) have been investigated using x-ray diffraction, field- and temperature-dependent ac magnetic susceptibility,DC magnetization (5-340 K; 0-5 T) and 57Fe Mössbauer spectroscopy (5-300 K). TbNi2Mnx crystallize in the MgCu2-type structure (space group Fd-3m). The additional contributions to the magnetic energy terms from transition metal-transition metal interactions (T-T) and rare earthtransition metal interactions (R-T) in RNi2Mn contribute to their increased magnetic ordering temperatures compared with RNi2 and RMn2. Both the lattice constant a and the Curie temperature TC exhibit maximal values at the x=1 composition indicating strong magnetostructural …
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
Faculty of Engineering - Papers (Archive)
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 …
Strong 4f Electron Interaction And Magnetic Ordering Modification In Nd1-Xerxmno3 (0 Less Than Or Equal To X Less Than Or Equal To 0.5), Fang Hong, Zhenxiang Cheng, Xiaolin Wang
Strong 4f Electron Interaction And Magnetic Ordering Modification In Nd1-Xerxmno3 (0 Less Than Or Equal To X Less Than Or Equal To 0.5), Fang Hong, Zhenxiang Cheng, Xiaolin Wang
Faculty of Engineering - Papers (Archive)
Structural and magnetic properties have been studied in perovskite Nd1-xErxMnO3 (0 ≤ x ≤ 0.5). Er3+ doping enhances the Jahn-Teller distortion, strongly affects the Nd3+-Mn3+ interaction, destroys the intermediate state below the antiferromagnetic transition temperature in NdMnO3, and breaks the antiparallel arrangement between Nd3+ and Mn3+ spin ordering. The decreasing ferromagnetic component in magnetic hysteresis loops at 30 K indicates that the canted angles vary with x. These results offer strong evidence for the interaction between rare earth ions and transition metal ions and competition among rare …
Superconducting Transition Width Under Magnetic Field In Mgb2 Polycrystalline Samples, C.C Wang, R Zeng, Xun Xu, S. X. Dou
Superconducting Transition Width Under Magnetic Field In Mgb2 Polycrystalline Samples, C.C Wang, R Zeng, Xun Xu, S. X. Dou
Faculty of Engineering - Papers (Archive)
A systematic study on the superconducting transition width as a function of the applied magnetic field was performed in polycrystalline MgB2. A quantitative, yet universal relation between the two parameters was observed in all of the ceramics. It was found that the width decreases linearly with decreasing field in pure MgB2 samples. Whereas, samples with boron and/or Mg atoms partially replaced by other elements show this linear relation in the temperature range below 0.7–0.8 of the superconducting transition temperature (corresponding to a field of about 2 T), at temperatures higher than this range, an abnormal upturn in …
Enhancement Of Co Substitution Induced By Eu Codoping In Zno-Based Diluted Magnetic Semiconducting Thin Films, P Photongkam, Y B Zhang, M.H.N Assadi, S Li, D Yu, Mihail Ionescu, Alexey V. Pan
Enhancement Of Co Substitution Induced By Eu Codoping In Zno-Based Diluted Magnetic Semiconducting Thin Films, P Photongkam, Y B Zhang, M.H.N Assadi, S Li, D Yu, Mihail Ionescu, Alexey V. Pan
Faculty of Engineering - Papers (Archive)
To avoid the occurrence of doped magnetic ion clustering is a challenge in fabrication of diluted magnetic semiconductors (DMSs). In this work, we report the intrinsic ferromagnetic behavior in Co-doped ZnO DMSs induced by Eu codoping. Both structural parameters and magnetic properties demonstrate the existence of an interaction between Co and Eu ions. The observation of multiplet structures for the localized Co 3d states in x-ray absorption and x-ray magnetic circular dichroism characterization evidences that the codoped Eu plays an important role in facilitating the Co substitution of Zn, leading to intrinsic ferromagnetism.
Flux Pinning And Inhomogeneity In Magnetic Nanoparticle Doped Mgb2/Fe Wires, Nikolina Novosel, Damir Pajic, Mislav Mustapic, Emil Babic, Andrey Shcherbakov, Josip Horvat, Zeljko Skoko, Kreso Zadro
Flux Pinning And Inhomogeneity In Magnetic Nanoparticle Doped Mgb2/Fe Wires, Nikolina Novosel, Damir Pajic, Mislav Mustapic, Emil Babic, Andrey Shcherbakov, Josip Horvat, Zeljko Skoko, Kreso Zadro
Faculty of Engineering - Papers (Archive)
The effects of magnetic nanoparticle doping on superconductivity of MgB2/Fe wires have been investigated. Fe2B and SiO2-coated Fe2B particles with average diameters 80 and 150 nm, respectively, were used as dopands. MgB2 wires with different nanoparticle contents (0, 3, 7.5, 12 wt.%) were sintered at temperature 750°C. The magnetoresistivity and critical current density Jc of wires were measured in the temperature range 2–40 K in magnetic field B ≤ 16 T. Both transport and magnetic Jc were determined. Superconducting transition temperature Tc of doped wires decreases quite rapidly with …
Self-Doping Effect And Successive Magnetic Transitions In Superconducting Sr2 Vfeaso3, Guanghan Cao, Zhifeng Ma, Cao Wang, Yunlei Sun, Jinke Bao, Shuai Jiang, Yi Luo, Chunmu Feng, Yi Zhou, Zhi Xie, Fengchun Hu, Shiqiang Wei, I Nowik, I Felner, Lei Zhang, Zhu-An Xu, Fu-Chun Zhang
Self-Doping Effect And Successive Magnetic Transitions In Superconducting Sr2 Vfeaso3, Guanghan Cao, Zhifeng Ma, Cao Wang, Yunlei Sun, Jinke Bao, Shuai Jiang, Yi Luo, Chunmu Feng, Yi Zhou, Zhi Xie, Fengchun Hu, Shiqiang Wei, I Nowik, I Felner, Lei Zhang, Zhu-An Xu, Fu-Chun Zhang
Faculty of Engineering - Papers (Archive)
We have studied a quinary Fe-based superconductor Sr2VFeAsO3 by the measurements of x-ray diffraction, x-ray absorption, Mössbauer spectrum, resistivity, magnetization, and specific heat. This apparently undoped oxyarsenide is shown to be self-doped via electron transfer from the V3+ ions. We observed successive magnetic transitions within the VO2 layers: an antiferromagnetic transition at 150 K followed by a weak ferromagnetic transition at 55 K. The spin orderings within the VO2 planes are discussed based on mixed valence of V3+ and V4+.