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Full-Text Articles in Physical Sciences and Mathematics
Tunable Magnetic Properties Of Transition Metal Doped Mos2, Antonis N. Andiotis, Madhu Menon
Tunable Magnetic Properties Of Transition Metal Doped Mos2, Antonis N. Andiotis, Madhu Menon
Physics and Astronomy Faculty Publications
We report a detailed investigation of the electronic and magnetic properties of the transition metal (TM) doped two-dimensional (2D) MoS2 using ab initio calculations. The doping is achieved by substituting two or more Mo atoms by TM atoms of the 3d series. Additionally, the effect of codoping on the 2D MoS2 by cation-cation and cation-anion pairs is also investigated. Our results demonstrate that the TM doping of 2D MoS2 leads to a significant reduction of the energy gap and the appearance of magnetic features whose major characteristic is the ferromagnetic coupling of the TM dopants. The …
Magnetic Correlations And Pairing In The 1/5-Depleted Square Lattice Hubbard Model, Ehsan Khatami, Rajiv R.P. Singh, Warren E. Pickett, Richard T. Scalettar
Magnetic Correlations And Pairing In The 1/5-Depleted Square Lattice Hubbard Model, Ehsan Khatami, Rajiv R.P. Singh, Warren E. Pickett, Richard T. Scalettar
Faculty Publications
We study the single-orbital Hubbard model on the 1/5-depleted square-lattice geometry, which arises in such diverse systems as the spin-gap magnetic insulator CaV4O9 and ordered-vacancy iron selenides, presenting new issues regarding the origin of both magnetic ordering and superconductivity in these materials. We find a rich phase diagram that includes a plaquette singlet phase, a dimer singlet phase, a Néel and a block-spin antiferromagnetic phase, and stripe phases. Quantum Monte Carlo simulations show that the dominant pairing correlations at half filling change character from d wave in the plaquette phase to extended s wave upon transition to the Néel phase. …
Recent Ideas On The Calculation Of Lepton Anomalous Magnetic Moments, Michael I. Eides
Recent Ideas On The Calculation Of Lepton Anomalous Magnetic Moments, Michael I. Eides
Physics and Astronomy Faculty Publications
We discuss the recent claim [G. Mishima, arXiv:1311.7109; M. Fael and M. Passera, arXiv:1402.1575 [Phys. Rev. D (to be published)]] about discovery of a nonperturbative quantum-electrodynamic contribution of order (α/π)5 to lepton anomalous magnetic moments. We explain why this nonperturbative correction does not exist.
Neutron Diffraction Study Of Mnniga2 - Structural And Magnetic Behaviour, Jianli Wang, L Ma, M Hofmann, M Avdeev, S J. Kennedy, S J. Campbell, M F. Md Din, M Hoelzel, G H. Wu, S X. Dou
Neutron Diffraction Study Of Mnniga2 - Structural And Magnetic Behaviour, Jianli Wang, L Ma, M Hofmann, M Avdeev, S J. Kennedy, S J. Campbell, M F. Md Din, M Hoelzel, G H. Wu, S X. Dou
Australian Institute for Innovative Materials - Papers
MnNiGa2 crystallizes in the L21 (Heusler) structure and has a ferromagnetic ordering temperature TC ∼ 192 K. Rietveld refinement of the neutron diffraction patterns indicates that the Ga atoms occupy the equivalent 8c position, while Mn and Ni share the 4a (0, 0, 0) and 4b (0.5, 0.5, 0.5) sites with a mixed occupancy of Mn and Ni atoms. It is found that that ∼83% of Mn and ∼17% Ni are located at the 4a site while ∼83% of Ni and ∼17% Mn occupy the 4b site. There is no evidence of a magneto-volume effect around TC. In agreement with …
A Non-Erasable Magnetic Memory Based On The Magnetic Permeability, J R. Petrie, K A. Wieland, R A. Burke, G A. Newburgh, J E. Burnette, G A. Fisher, A S. Edelstein
A Non-Erasable Magnetic Memory Based On The Magnetic Permeability, J R. Petrie, K A. Wieland, R A. Burke, G A. Newburgh, J E. Burnette, G A. Fisher, A S. Edelstein
US Army Research
A non-erasable memory based on using differences in the magnetic permeability is demonstrated. The method can potentially store information indefinitely. Initially the high permeability bits were 10–50 μm wide lines of sputtered permalloy (Ni81Fe19) on a glass substrate. In a second writing technique a continuous film of amorphous, high permeability ferromagnetic Metglas (Fe78Si13Bg) was sputtered onto a similar glass substrate. Low permeability, crystalline 50 Jlm wide lines were then written in the film by laser heating. Both types of written media were read by applying an external probe field that is locally modified by the permeability …
Diffusive Electron Heat Flow And Temperature Variance Along Magnetic Field Lines, Michael Kushlan
Diffusive Electron Heat Flow And Temperature Variance Along Magnetic Field Lines, Michael Kushlan
Physics Capstone Projects
In this research we examine how electron heat moves along magnetic field lines and how this affects temperature variations in plasmas. Specifically we wrote FORTRAN code to solve the electron temperature equation numerically. We also solved the steady state electron temperature equation analytically using an integrating factor. We verified that the numerical and analytical solutions obtained the same result. Finally we calculated the standard deviation of temperature in our domain for the steady state. Gaussian legendre quadrature was used to integrate various functions. We represented our magnetic field and heat source with Fourier series. The sin and cosine coefficients for …
Magnetic Transitions And The Magnetocaloric Effect In The Pr 1-Xyxmn2ge2 System, Jianli Wang, S J. Campbell, M F. Md Din, S J. Kennedy, M Hofmann
Magnetic Transitions And The Magnetocaloric Effect In The Pr 1-Xyxmn2ge2 System, Jianli Wang, S J. Campbell, M F. Md Din, S J. Kennedy, M Hofmann
Australian Institute for Innovative Materials - Papers
Layered rare earth compounds in the RMn2X2 series (R = rare-earth; X = Ge, Si) are of interest for potential cooling applications at lower temperatures as they enable the structural and magnetic behavior to be controlled via substitution of R, Mn, and X atoms on the 2a, 4d, and 4e sites respectively. We continue investigations of the Pr1−xYxMn2Ge2 magnetic phase diagram as functions of both composition and Mn-Mn spacing using X-ray and neutron diffraction, magnetization and differential scanning calorimetry measurements. Pr1−xYxMn2Ge2 exhibits an extended region of re-entrant ferromagnetism around x ∼ 0.5 with re-entrant ferromagnetism at inline image for Pr0.5Y0.5Mn2Ge2. …
Magnetic Properties And Magnetocaloric Effect Of Ndmn2-Xcuxsi2 Compounds, M F. Md Din, Jianli Wang, M Avdeev, Q F. Gu, R Zeng, S J. Campbell, S J. Kennedy, S X. Dou
Magnetic Properties And Magnetocaloric Effect Of Ndmn2-Xcuxsi2 Compounds, M F. Md Din, Jianli Wang, M Avdeev, Q F. Gu, R Zeng, S J. Campbell, S J. Kennedy, S X. Dou
Australian Institute for Innovative Materials - Papers
Structural and magnetic properties of NdMn2−x Cu xSi2 compounds (x = 0-1.0) have been investigated by high intensity x-ray and resolution neutron diffraction (3-450 K), specific heat, dc magnetization, and differential scanning calorimetry measurements. Substitution of Cu for Mn leads to an increase in the lattice parameter a but a decrease in c at room temperature. Two magnetic phase transitions have been found for NdMn2−x Cu xSi2 compounds with TN for the antiferromagnetic ordering of Mn-sublatttice and TC for the Nd-sublattice ferromagnetic ordering, respectively. TC increases significantly with increasing Cu content from 36 K at x = 0 to 100 …
Direct Evidence Of Ni Magnetic Moment In Tbni2mn-X-Ray Magnetic Circular Dichroism, D H. Yu, Meng-Jie Huang, Jianli Wang, Hui-Chia Su, Hong-Ji Lin, Chien-Te Chen, S J. Campbell
Direct Evidence Of Ni Magnetic Moment In Tbni2mn-X-Ray Magnetic Circular Dichroism, D H. Yu, Meng-Jie Huang, Jianli Wang, Hui-Chia Su, Hong-Ji Lin, Chien-Te Chen, S J. Campbell
Australian Institute for Innovative Materials - Papers
We have investigated the individual magnetic moments of Ni, Mn and Tb atoms in the intermetallic compound TbNi2Mn in the Laves phase (magnetic phase transition temperature TC ∼131 K) by X-ray magnetic circular dichroism (XMCD) studies at 300 K, 80 K and 20 K. Analyses of the experimental results reveal that Ni atoms at 20 K in an applied magnetic field of 1 T carry an intrinsic magnetic moment of spin and orbital magnetic moment contributions 0.53±0.01 μB and 0.05±0.01 μB, respectively. These moment values are similar to those of the maximum saturated moment of Ni element. A very small …
Platinum Dendritic Nanoparticles With Magnetic Behavior, Wenxian Li, Ziqi Sun, Dongliang Tian, Ivan P. Nevirkovets, S X. Dou
Platinum Dendritic Nanoparticles With Magnetic Behavior, Wenxian Li, Ziqi Sun, Dongliang Tian, Ivan P. Nevirkovets, S X. Dou
Australian Institute for Innovative Materials - Papers
Magnetic nanoparticles have attracted increasing attention for biomedical applications in magnetic resonance imaging, high frequency magnetic field hyperthermia therapies, and magnetic-field-gradient-targeted drug delivery. In this study, three-dimensional (3D) platinum nanostructures with large surface area that features magnetic behavior have been demonstrated. The well-developed 3D nanodendrites consist of plentiful interconnected nano-arms ∼4 nm in size. The magnetic behavior of the 3D dendritic Pt nanoparticles is contributed by the localization of surface electrons due to strongly bonded oxygen/Pluronic F127 and the local magnetic moment induced by oxygen vacancies on the neighboring Pt and O atoms. The magnetization of the nanoparticles exhibits a …
90° Magnetic Coupling In A Nife/Femn/Biased Nife Multilayer Spin Valve Component Investigated By Polarized Neutron Reflectometry, S J. Callori, J Bertinshaw, David L. Cortie, J W. Cai, A P. Le Brun, T Zhu, Frank Klose
90° Magnetic Coupling In A Nife/Femn/Biased Nife Multilayer Spin Valve Component Investigated By Polarized Neutron Reflectometry, S J. Callori, J Bertinshaw, David L. Cortie, J W. Cai, A P. Le Brun, T Zhu, Frank Klose
Australian Institute for Innovative Materials - Papers
We have observed 90° magnetic coupling in a NiFe/FeMn/biased NiFe multilayer system using polarized neutron reflectometry. Magnetometry results show magnetic switching for both the biased and free NiFe layers, the latter of which reverses at low applied fields. As these measurements are only capable of providing information about the total magnetization within a sample, polarized neutron reflectometry was used to investigate the reversal behavior of the NiFe layers individually. Both the non-spin-flip and spin-flip neutron reflectometry signals were tracked around the free NiFe layer hysteresis loop and were used to detail the evolution of the magnetization during reversal. At low …
Magnetic Properties And Magnetocaloric Effect In Layered Ndmn 1.9v0.1si2, M F. Md Din, Jianli Wang, R Zeng, Shane Kennedy, S J. Campbell, S X. Dou
Magnetic Properties And Magnetocaloric Effect In Layered Ndmn 1.9v0.1si2, M F. Md Din, Jianli Wang, R Zeng, Shane Kennedy, S J. Campbell, S X. Dou
Australian Institute for Innovative Materials - Papers
The structural and magnetic properties of the compounds NdMn2-xVxSi2 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 layered NdMn1.9V0.1Si2 are been indicate at TC ~ 24 K and TN ~ 376 K respectively. The giant magnetocaloric effect (GMCE) around TC is found in layered NdMn1.9V0.1Si2 associated with first order magnetic transition from antiferromagnetic [AFil-type] to ferromagnetic [F(Nd)+Fmc]. This behaviorhas been confirmed as contribution of the magnetostructural coupling by using neutron powder diffraction. The magnetic entropy …
A Comparative Study Of Magnetic Behaviors In Tbni2, Tbmn2 And Tbni2mn, Jianli Wang, M F. Md Din, Shane Kennedy, F Hong, Stewart J. Campbell, A J. Studer, G H. Wu, Zhenxiang Cheng, S X. Dou
A Comparative Study Of Magnetic Behaviors In Tbni2, Tbmn2 And Tbni2mn, Jianli Wang, M F. Md Din, Shane Kennedy, F Hong, Stewart J. Campbell, A J. Studer, G H. Wu, Zhenxiang Cheng, S X. Dou
Australian Institute for Innovative Materials - Papers
All TbNi2, TbMn2, and TbNi2Mn compounds exhibit the cubic Laves phase with AB2-type structure in spite of the fact that the ratio of the Tb to transition-metal components in TbNi2Mn is 1:3. Rietveld refinement indicates that in TbNi2Mn the Mn atoms are distributed on both the A (8a) and B (16d) sites. The values of the lattice constants were measured to be a = 14.348 Å (space group F-43 m), 7.618 Å, and 7.158 Å (space group Fd-3 m) for TbNi2, TbMn2, and TbNi2Mn, respectively. The magnetic transition temperatures TC were found to be TC = 38 K and TC …
Magnetic Transitions In Lafe13-X-Ycoysix Compounds, Jianli Wang, S J. Campbell, S J. Kennedy, P Shamba, R Zeng, S X. Dou, G H. Wu
Magnetic Transitions In Lafe13-X-Ycoysix Compounds, Jianli Wang, S J. Campbell, S J. Kennedy, P Shamba, R Zeng, S X. Dou, G H. Wu
Australian Institute for Innovative Materials - Papers
The magnetic properties of a set of LaFe13−x−yCoySix compounds (x = 1.6 − 2.6; y = 0, y = 1.0) have been investigated using magnetic measurements, thermal expansion, 57Fe Mössbauer spectroscopy and high resolution neutron powder diffraction methods over the temperature range 10–300 K. The natures of the magnetic transitions in these LaFe13−x−yCoySix compounds have been determined. The Curie temperatures of LaFe13−xSix were found to increase with Si content from TC = 219(5) K for Si content x = 1.6 to TC = 250(5) K for x = 2.6. Substitution of Co for Fe in LaFe10.4Si2.6 resulted in a further …
Significant Tunability Of Thin Film Functionalities Enabled By Manipulating Magnetic And Structural Nano-Domains, Igor A. Golovchanskiy, Alexey V. Pan, Sergey A. Fedoseev, Michael Higgins
Significant Tunability Of Thin Film Functionalities Enabled By Manipulating Magnetic And Structural Nano-Domains, Igor A. Golovchanskiy, Alexey V. Pan, Sergey A. Fedoseev, Michael Higgins
Australian Institute for Innovative Materials - Papers
The influence of laser frequency on the structure and physical properties of thin films grown by pulsed laser deposition has been studied. Different types of thin films, hard ferromagnetic FePt L10 and quasi-single crystal superconducting YBa2Cu3O7 (YBCO), have been used for demonstration of the effect. Significant structural modifications have been obtained for the films with similar thicknesses. These modifications are shown to dramatically control their corresponding properties, providing an instrumental ability for tuning the practical characteristics of the films by changing the laser frequency of their deposition. In particular, 20-fold increase of coercive field and modification of demagnetization mechanism are …
Magnetic Properties And Magnetocaloric Effect In Layered Ndmn1.9ti0.1si2, M F. Md Din, Jianli Wang, Shane J. Kennedy, Stewart J. Campbell, S X. Dou
Magnetic Properties And Magnetocaloric Effect In Layered Ndmn1.9ti0.1si2, M F. Md Din, Jianli Wang, Shane J. Kennedy, Stewart J. Campbell, S X. Dou
Australian Institute for Innovative Materials - Papers
The structural and magnetic properties of the NdMn1.9Ti0.1Si2 compund have been studied by high-intensity x-ray and high-resolution neutron powder diffraction, specific heat, dc magnetization, and differential scanning calorimetry measurements over the temperature range of 3-450 K. The Curie temperature and Néel temperature of layered NdMn1.9Ti0.1Si2 are indicated as TC ~ 22 K and TN ~ 374 K respectively. The first order magnetic transition from antiferromagnetic [AFil-type] to ferromagnetic [F(Nd)+Fmc] around TC is found in layered NdMn1.9Ti0.1Si2 and is …
Spin Memristive Magnetic Tunnel Junctions With Coo-Zno Nano Composite Barrier, Qiang Li, Ting-Ting Shen, Yan-Ling Cao, Kun Zhang, Shi-Shen Yan, Yu-Feng Tian, Shi-Shou Kang, Ming-Wen Zhao, You-Yong Dai, Yan-Xue Chen, Guo-Lei Liu, Liang-Mo Mei, Xiaolin Wang, Peter Grunberg
Spin Memristive Magnetic Tunnel Junctions With Coo-Zno Nano Composite Barrier, Qiang Li, Ting-Ting Shen, Yan-Ling Cao, Kun Zhang, Shi-Shen Yan, Yu-Feng Tian, Shi-Shou Kang, Ming-Wen Zhao, You-Yong Dai, Yan-Xue Chen, Guo-Lei Liu, Liang-Mo Mei, Xiaolin Wang, Peter Grunberg
Australian Institute for Innovative Materials - Papers
The spin memristive devices combining memristance and tunneling magnetoresistance have promising applications in multibit nonvolatile data storage and artificial neuronal computing. However, it is a great challenge for simultaneous realization of large memristance and magnetoresistance in one nanoscale junction, because it is very hard to find a proper spacer layer which not only serves as good insulating layer for tunneling magnetoresistance but also easily switches between high and low resistance states under electrical field. Here we firstly propose to use nanon composite barrier layers of CoO-ZnO to fabricate the spin memristive Co/CoO-ZnO/Co magnetic tunnel junctions. The bipolar resistance switching ratio …
Magnetic Phase Transitions And Entropy Change In Layered Ndmn1.7cr0.3si2, M F. Md Din, Jianli Wang, S J. Campbell, A J. Studer, M Avdeev, S J. Kennedy, Q F. Gu, R Zeng, S X. Dou
Magnetic Phase Transitions And Entropy Change In Layered Ndmn1.7cr0.3si2, M F. Md Din, Jianli Wang, S J. Campbell, A J. Studer, M Avdeev, S J. Kennedy, Q F. Gu, R Zeng, S X. Dou
Australian Institute for Innovative Materials - Papers
A giant magnetocaloric effect has been observed around the Curie temperature, TC ∼ 42 K, in NdMn1.7Cr0.3Si2 with no discernible thermal and magnetic hysteresis losses. Below 400 K, three magnetic phase transitions take place around 380 K, 320 K and 42 K. Detailed high resolution synchrotron and neutron powder diffraction (10-400 K) confirmed the magnetic transitions and phases as follows: TN intra ∼ 380 K denotes the transition from paramagnetism to intralayer antiferromagnetism (AFl), TN inter ∼ 320 K represents the transition from the AFl structure to the canted antiferromagnetic spin structure (AFmc), while TC ∼ 42 K denotes the …