scholarly journals A Comparative Study of Magnetic Properties of Large Diameter Co Nanowires and Nanotubes

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 692 ◽  
Author(s):  
Jose Fernandez-Roldan ◽  
Dieivase Chrischon ◽  
Lucio Dorneles ◽  
Oksana Chubykalo-Fesenko ◽  
Manuel Vazquez ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Comparative Study ◽  
Large Diameter ◽  
Hysteresis Loops ◽  
Magnetic Behavior ◽  
Grain Structure ◽  
Micromagnetic Simulations ◽  
Array Configuration ◽  
Co Nanowires ◽  
Magnetostatic Interactions

A comparative study of the magnetic properties of the arrays of Co nanowires and nanotubes with large external diameters (180 nm) has been carried out. The nanowires/nanotubes were grown by electrodeposition into the self-assembled pores of anodic alumina membranes. The experimental study of their magnetic behavior was focused on the angular dependence of hysteresis loops and their parameters. In both nanowire and nanotube arrays, from the analysis of experimental data, effective longitudinal magnetic anisotropy is concluded, which is stronger in the case of the nanotube array. In addition, the extremely small remanence observed for all loops indicates the important role played by magnetostatic interactions. Micromagnetic simulations were first performed considering intrinsic shape and magnetocrystalline anisotropy terms, together with an effective easy-plane anisotropy to account for those magnetostatic interactions. A qualitative agreement between experiments and simulations is found despite the complexity introduced by the intrinsic and extrinsic array properties (i.e., large diameters, grain structure, and array configuration). In addition, simulations were also carried out for individual nanowire/nanotube with a particular emphasis to understand their differences at the remanence, due to pure geometry contribution.

scholarly journals Single-molecule magnet behavior in 2,2’-bipyrimidine-bridged dilanthanide complexes

2016 ◽  
Vol 7 ◽  
pp. 126-137 ◽  
Author(s):  
Wen Yu ◽  
Frank Schramm ◽  
Eufemio Moreno Pineda ◽  
Yanhua Lan ◽  
Olaf Fuhr ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Single Molecule ◽  
Energy Barrier ◽  
Lanthanide Complexes ◽  
Hysteresis Loops ◽  
Magnetic Behavior ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Single Molecule Magnet ◽  
Homogeneous Film

A series of 2,2’-bipyrimidine-bridged dinuclear lanthanide complexes with the general formula [Ln(tmhd)3]2bpm (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionate, bpm = 2,2’-bipyrimidine, Ln = Gd(III), 1; Tb(III), 2; Dy(III), 3; Ho(III), 4 and Er(III), 5) has been synthesized and characterized. Sublimation of [Tb(tmhd)3]2bpm onto a Au(111) surface leads to the formation of a homogeneous film with hexagonal pattern, which was studied by scanning tunneling microscopy (STM). The bulk magnetic properties of all complexes have been studied comprehensively. The dynamic magnetic behavior of the Dy(III) and Er(III) compounds clearly exhibits single molecule magnet (SMM) characteristics with an energy barrier of 97 and 25 K, respectively. Moreover, micro-SQUID measurements on single crystals confirm their SMM behavior with the presence of hysteresis loops.

scholarly journals Structural, Morphological and Magnetic Properties of Nd and Co co-doped BiFeO3 Ceramics at Room temperature

2017 ◽  
Vol 41 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Tamanna Mariam ◽  
Shamima Choudhury
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Hysteresis Loops ◽  
Magnetic Behavior ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Average Grain Size ◽  
Co Doped ◽  
Simultaneous Substitution

Synthesis and characterization of BiFeO3 samples, co-doped with rare earth Nd and Co in place of Bi and Fe respectively were investigated at room temperature (RT). The formula of the four samples are Co-doped BiFe1–xCoxO3 (x = 0.05-0.10) and Nd and Co co-substituted Bi0.95Nd0.05Fe0.95Co0.05O3 and Bi0.90Nd0.10Fe0.90Co0.10O3. These ceramic samples were synthesized by conventional solid state reaction method. The X-ray diffraction patterns clearly reveal that the secondary impurity phases were eliminated significantly due to the simultaneous substitution of Nd and Co in place of Bi and Fe respectively of BiFeO3 ceramics. The surface morphology of the synthesized samples was found to improve due to the simultaneous substitution of Nd and Co in place of Bi and Fe in BiFeO3. The average grain size of the first sample with 5% doping of Co in place of Fe was 1.5?m. In the second sample with 10% Co doping in place of Fe, the average grain size became 1.25 ?m. In presence of 5% Nd in place of Bi as well as with 5% doping of Co in place of Fe , grain size reduced to 0.75?m. The sample with 10% doping of Nd and Co in place of Bi and Fe respectively, average grain size decreased to 0.5?m. The EDX spectroscpoy ensured the presence of Bi, Nd, Fe, Co and O in these samples and their percentage of mass and atoms. Magnetic properties of the samples were also investigated at room temperature by measuring magnetization versus magnetic field (M-H) hysteresis loops. The wider loop clearly demonstrates the significant improvement of the magnetic behavior in 10% Nd and Co doped Bi0.90Nd0.10Fe0.90Co0.10O3 sample. The enhanced magnetic properties might be attributed to the substitution induced suppression of spiral spin structure of BiFeO3. The outcome of this investigation suggests the potentiality of the simultaneous doping of Nd and Co in BiFeO3 ceramics to improve their structural, morphological and magnetic characteristics.Journal of Bangladesh Academy of Sciences, Vol. 41, No. 1, 85-93, 2017

scholarly journals Modeling hysteresis curves of La(FeCoSi)13 compound near the transition point with the GRUCAD model

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 266-270 ◽  
Author(s):  
Roman Gozdur ◽  
Piotr Gębara ◽  
Krzysztof Chwastek
Keyword(s):  
Phase Transition ◽  
Magnetic Properties ◽  
Transition Point ◽  
Magnetic Phase ◽  
Hysteresis Loops ◽  
Magnetic Behavior ◽  
Hysteresis Model ◽  
New Approach ◽  
Influence Of Temperature ◽  
Influence Of Temperature On

Abstract The paper presents a new approach to modeling of magnetic properties and the influence of temperature on hysteresis loops in La(FeCoSi)13 magnetocaloric compound. The GRUCAD hysteresis model has been used for analysis of magnetic behavior in the vicinity of the magnetic phase transition. The modeling results are in a qualitative agreement with experiment.

THE GIANT MAGNETOSTRICTION AND MAGNETIC PROPERTIES OF THE AMORPHOUS ALTERNANT [Tb/Fe/Dy]n AND [Fe/Tb/Fe/Dy]m NANO-MULTILAYER FILMS

2008 ◽  
Vol 15 (05) ◽  
pp. 619-623
Author(s):  
X. D. LI ◽  
L. K. PAN ◽  
Z. J. ZHAO ◽  
S. M. HUANG ◽  
Y. W. CHEN ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Domain Wall Motion ◽  
Magnetic Behavior ◽  
Multilayer Films ◽  
Film Plane ◽  
Soft Magnetic ◽  
Low Field ◽  
Giant Magnetostriction

The magnetic properties and giant magnetostriction effect (GMS) of the amorphous alternant [ Tb / Fe / Dy ]n (named S1) and [ Fe / Tb / Fe / Dy ]m (named S2) nano-multilayer films have been studied. The magnetic hysteresis loops show that easy magnetic direction changes from perpendicular to the film plane (S1) to parallel to the film plane (S2). S2 has better soft magnetic properties and low-field giant magnetostriction effect than that of S1, due to the exchanging interaction between the hard GMS layer and the soft layer Fe . The different magnetic behavior is explained by considering the nature of the magnetization process, i.e. domain-wall motion and spin rotation.

Ground state phase diagrams and magnetic properties of the double perovskite La2NiMnO6

2019 ◽  
Vol 16 (2) ◽  
pp. 281-292
Author(s):  
Ibtissam El Housni ◽  
Samira Idrissi ◽  
Najlae El Mekkaoui ◽  
Sara Mtougui ◽  
Rajaa Khalladi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Diagrams ◽  
Crystal Field ◽  
Ground State ◽  
Exchange Coupling ◽  
Hysteresis Loops ◽  
Magnetic Behavior ◽  
Double Perovskite ◽  
Physical Parameters ◽  
Content Type

Purpose The purpose of this paper is to investigate the magnetic properties and the ground state phase diagrams of the double perovskite La2NiMnO6 using the Monte Carlo simulations (MCS). Design/methodology/approach In this work, the authors propose a Hamiltonian modeling this compound, described by an Ising model, with different exchange coupling interactions J11, J12 and J22 between the only magnetic atoms Ni and Mn. Findings Starting with the ground state phase diagrams, the authors present and discuss the stable configurations in different physical parameter planes. On the other hand, the authors present the investigation of the magnetic properties and the magnetization behaviors of the magnetic susceptibilities, as a function of temperature, crystal field, the exchange coupling interactions and the Zeeman energy. To complete this study, the authors illustrate the dependency of the total magnetizations for the hysteresis loops of the double perovskite La2NiMnO6 compound. This study is done for fixed values of temperature, the exchange coupling interactions and crystal field. Originality/value The authors modeled the different physical parameters of the double perovskite La2NiMnO with a Hamiltonian describing the system. At T=0K, the authors discussed the ground state phase diagrams of different physical parameters planes. For non-null temperature values, the authors studied the magnetic behavior of the double perovskite La2NiMnO using MCS under the metropolis algorithm. The authors expect that the results of these simulations can provide some important keys for the experimental research and technology applications of the double perovskite La2NiMnO6 in the future.

Magnetic Properties of xCeO2•(50 − x) PbO•50B2O3 Glasses and Glass Ceramics

2017 ◽  
Vol 13 (1) ◽  
pp. 4486-4494 ◽  
Author(s):  
G.El Damrawi ◽  
F. Gharghar
Keyword(s):  
Magnetic Properties ◽  
Large Scale ◽  
Glass Ceramics ◽  
Magnetic Behavior ◽  
Crystal Formation ◽  
Dual Roles ◽  
Effective Agent ◽  
Ordered Structures ◽  
Essential Change

Cerium oxide in borate glasses of composition xCeO2·(50 − x)PbO·50B2O3 plays an important role in changing both microstructure and magnetic behaviors of the system. The structural role of CeO2 as an effective agent for cluster and crystal formation in borate network is clearly evidenced by XRD technique. Both structure and size of well-formed cerium separated clusters have an effective influence on the structural properties. The cluster aggregations are documented to be found in different range ordered structures, intermediate and long range orders are the most structures in which cerium phases are involved. The nano-sized crystallized cerium species in lead borate phase are evidenced to have magnetic behavior.  The criteria of building new specific borate phase enriched with cerium as ferrimagnetism has been found to keep the magnetization in large scale even at extremely high temperature. Treating the glass thermally or exposing it to an effective dose of ionized radiation is evidenced to have an essential change in magnetic properties. Thermal heat treatment for some of investigated materials is observed to play dual roles in the glass matrix. It can not only enhance alignment processes of the magnetic moment but also increases the capacity of the crystallite species in the magnetic phases. On the other hand, reverse processes are remarked under the effect of irradiation. The magnetization was found to be lowered, since several types of the trap centers which are regarded as defective states can be produced by effect of ionized radiation. 

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Saturation Magnetization ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Rare Earth Ions ◽  
Ion Concentration ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Combustion Technique

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

scholarly journals Micromagnetic Simulations of Fe and Ni Nanodot Arrays Surrounded by Magnetic or Non-Magnetic Matrices

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 349
Author(s):  
Devika Sudsom ◽  
Andrea Ehrmann
Keyword(s):  
Magnetic Materials ◽  
Data Storage ◽  
Magnetization Reversal ◽  
Hysteresis Loops ◽  
Object Oriented ◽  
Basic Research ◽  
Memory Systems ◽  
The Other ◽  
Micromagnetic Simulations ◽  
Nanodot Arrays

Combining clusters of magnetic materials with a matrix of other magnetic materials is very interesting for basic research because new, possibly technologically applicable magnetic properties or magnetization reversal processes may be found. Here we report on different arrays combining iron and nickel, for example, by surrounding circular nanodots of one material with a matrix of the other or by combining iron and nickel nanodots in air. Micromagnetic simulations were performed using the OOMMF (Object Oriented MicroMagnetic Framework). Our results show that magnetization reversal processes are strongly influenced by neighboring nanodots and the magnetic matrix by which the nanodots are surrounded, respectively, which becomes macroscopically visible by several steps along the slopes of the hysteresis loops. Such material combinations allow for preparing quaternary memory systems, and are thus highly relevant for applications in data storage and processing.

scholarly journals Tunable magnetization steps in mixed valent ferromagnet Eu2CoMnO6

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nara Lee ◽  
Jong Hyuk Kim ◽  
Dong Gun Oh ◽  
Hyun Jun Shin ◽  
Hwan Young Choi ◽  
...  
Keyword(s):  
Material Processing ◽  
Magnetic Properties ◽  
Single Crystals ◽  
Magnetic State ◽  
Hysteresis Loops ◽  
Double Perovskite ◽  
Processing Parameters ◽  
Perovskite Oxides ◽  
Efficient Approach ◽  
Isothermal Magnetization

AbstractMagnetic properties can be manipulated to enhance certain functionalities by tuning different material processing parameters. Here, we present the controllable magnetization steps of hysteresis loops in double-perovskite single crystals of Eu2CoMnO6. Ferromagnetic order emerges below TC ≈ 122 K along the crystallographic c axis. The difficulty in altering Co2+ and Mn4+ ions naturally induces additional antiferromagnetic clusters in this system. Annealing the crystals in different gas environments modifies the mixed magnetic state, and results in the retardation (after O2-annealing) and bifurcation (after Ar-annealing) of the magnetization steps of isothermal magnetization. This remarkable variation offers an efficient approach for improving the magnetic properties of double-perovskite oxides.

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