Quantum Theory of Magnetoelectric Properties of Rare-Earth Alumoborates: Holmium Alumoborate

2014 ◽  
Vol 215 ◽  
pp. 95-99
Author(s):  
Nadezhda V. Kostyuchenko ◽  
Alexander I. Popov ◽  
Anatoly K. Zvezdin
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Quantum Theory ◽  
Magnetoelectric Effect ◽  
Magnetoelectric Properties ◽  
Magnetization Processes

The magnetization processes of HoAl3(BO3)4rare-earth aluminum borates have been studied theoretically. Magnetic properties of the crystals were examined. The dependencies of the magnetic susceptibility on the magnitude and direction of magnetic field were calculated. Study of a magnetoelectric effect was performed and the dependencies of the polarization on the strength and orientation of a magnetic field and temperature were obtained. A comparison of the theoretical and experimental data was performed, their consistency has been ascertained.

Magnetic Properties of PrхY1-xFe3(BO3)4

2015 ◽  
Vol 233-234 ◽  
pp. 360-363
Author(s):  
A.I. Pankrats ◽  
A.A. Demidov ◽  
D.A. Velikanov ◽  
V.I. Tugarinov ◽  
V.L. Temerov
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Magnetic Properties ◽  
Rare Earth ◽  
Field Model ◽  
Field Approximation ◽  
Magnetization Curves ◽  
Extensive Experimental Data ◽  
Theory And Experiment ◽  
Good Agreement

The magnetic properties of trigonal PrxY1-xFe3(BO3)4 compound have been investigated. Anomalies on the magnetization curves induced by a magnetic field are observed for each composition. The calculations were performed using a molecular-field approximation and a crystal-field model for the rare-earth subsystem. Extensive experimental data on the magnetic properties of PrxY1-xFe3(BO3)4 have been interpreted and good agreement between theory and experiment has been achieved.

WANG–LANDAU SIMULATION ON THERMODYNAMIC AND MAGNETIC PROPERTIES OF HONEYCOMB LATTICE

2011 ◽  
Vol 25 (26) ◽  
pp. 3435-3442
Author(s):  
XIAOYAN YAO
Keyword(s):  
Magnetic Field ◽  
Monte Carlo Simulation ◽  
Magnetic Properties ◽  
Free Energy ◽  
Magnetic Susceptibility ◽  
Magnetic Property ◽  
Ground State ◽  
Antiferromagnetic Order ◽  
Honeycomb Lattice ◽  
Antiferromagnetic Ising Model

Wang–Landau algorithm of Monte Carlo simulation is performed to understand the thermodynamic and magnetic properties of antiferromagnetic Ising model on honeycomb lattice. The internal energy, specific heat, free energy and entropy are calculated to present the thermodynamic behavior. For magnetic property, the magnetization and magnetic susceptibility are discussed at different temperature upon different magnetic field. The antiferromagnetic order is confirmed to be the ground state of the system, and it can be destroyed by a large magnetic field.

scholarly journals Slow magnetisation relaxation in tetraoxolene-bridged rare earth complexes

2017 ◽  
Vol 46 (40) ◽  
pp. 13756-13767 ◽  
Author(s):  
Maja A. Dunstan ◽  
Elodie Rousset ◽  
Marie-Emmanuelle Boulon ◽  
Robert W. Gable ◽  
Lorenzo Sorace ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Slow Relaxation ◽  
Rare Earth Complexes ◽  
Zero Field ◽  
Ac Magnetic Susceptibility ◽  
Quantum Tunnelling ◽  
Dc Magnetic Field

Two tetraoxolene-bridged dinuclear Dy(iii) complexes exhibit slow relaxation in ac magnetic susceptibility studies with zero-field quantum tunnelling of the magnetisation that is suppressed by the application of a dc magnetic field.

scholarly journals Manganese/Yttrium Codoped Strontium Nanohexaferrites: Evaluation of Magnetic Susceptibility and Mossbauer Spectra

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 24 ◽  
Author(s):  
Munirah Almessiere ◽  
Yassine Slimani ◽  
Hakan Güngüneş ◽  
Abdulhadi Baykal ◽  
S.V. Trukhanov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Mössbauer Spectra ◽  
Ac Susceptibility ◽  
Sol Gel ◽  
Hyperfine Magnetic Field ◽  
Analytical Techniques ◽  
Magnetic Interactions ◽  
Mossbauer Spectra

Manganese (Mn)- and yttrium (Y)-substituted Sr-nanohexaferrites (MYSNHFs) of composition Sr1−xMnxFe12−xYxO19 (with 0.0 ≤ x ≤ 0.5) were prepared by citrate sol-gel autocombustion method. As-prepared MYSNHFs were characterized via diverse analytical techniques to determine the influence of Mn and Y cosubstitution on their microstructures and magnetic properties. 57Fe Mössbauer spectra of the MYSNHFs were used to evaluate the variation in the line width, isomer shift, quadrupole splitting, and hyperfine magnetic field values. It was shown that the dopant ions could preferentially occupy the 12k, 4f2, and 2b sites. Furthermore, the observed shift in the blocking temperatures of the studied MYSNHFs towards lower values with rising Mn2+ and Y3+ contents was attributed to the overall particles size reduction. Meanwhile, the AC susceptibility of the proposed MYSNHFs revealed that the magnetic interactions were weakened with the increase in dopant contents which was ascribed to the replacement of both Sr2+ and Fe3+ ions by the Mn2+ and Y3+ dopants.

GENERATING OF ELECTRICITY FROM MAGNETOELECTRIC COMPOSITE WITH USE OF CHANGES IN DIRECTION OF MAGNETIC FIELD VECTOR

2017 ◽  
Vol 186 (4) ◽  
pp. 283-293
Author(s):  
Rafał MECH
Keyword(s):  
Magnetic Field ◽  
Piezoelectric Material ◽  
Hybrid Material ◽  
Magnetoelectric Effect ◽  
Hybrid Structure ◽  
Field Vector ◽  
Magnetic Field Vector ◽  
Magnetoelectric Composite ◽  
Magnetoelectric Properties ◽  
Prepared Material

Paper shows study on the magnetoelectric composite material placed in an external magnetic field with changing magnetic field vecotr. An experimental setup for investigation of magnetoelectric properties of magnetostrictive-piezoelectric material was prepared. The hybrid structure is made of magnetostrictive composite (based on Terfenol-D) and piezoelectric material. Experimental results shown the response of prepared hybrid material to the rate of changes of direction of magnetic field vector. Investigation were mainly focused on possibility of generating of electric power from prepared material. It was found that the prepared hybrid material exhibits magnetoelectric effect in the case of work when direction of magnetic field vector was changing. This effect might be use in Energy Harvesting applications.

Magnetic Properties of Pbl-xGdxTe

1986 ◽  
Vol 89 ◽  
Author(s):  
M. Gorska ◽  
J. R. Anderson ◽  
Z. Golacki
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Exchange Interaction ◽  
Magnetic Field Dependence ◽  
Antiferromagnetic Exchange ◽  
Brillouin Function ◽  
Parameter Values ◽  
Mn Doped ◽  
The Magnetic Field

AbstractThe magnetization and magnetic susceptibility of Bridgman-grown Pb1-xGdxTe have been measured over a temperature range from 2 to 300 K and in magnetic fields from 0.01 to 50 κOe. The x-values of the crystals ranged from 0.03 to 0.07. The magnetic susceptibility followed a Curie-Weiss behavior, χ = C/(T + θ), with positive θ implying an antiferromagnetic exchange interaction between Gd ions. The magnetic field dependence of the magnetization was fitted to a modified Brillouin function with parameter values that agreed fairly well with those from Curie-Weiss plots. The magnitude of θ was comparable to the value found for Pb1-xMnxTe for similar x values; but since the ion spin is bigger for Gd this suggests that the exchange interaction in Gd-doped PbTe is roughly half the value in Mn-doped PbTe.

Magnetoelectric Properties in Nickel Ferrite – Niobate Relaxor Bulk Composites

2012 ◽  
Vol 77 ◽  
pp. 215-219
Author(s):  
Piotr Guzdek
Keyword(s):  
Magnetic Field ◽  
Nickel Ferrite ◽  
Room Temperature ◽  
Single Phase ◽  
Magnetoelectric Effect ◽  
Multiferroic Materials ◽  
Fundamental Interest ◽  
Practical Applications ◽  
Magnetoelectric Properties ◽  
Properties Of Composites

Magnetoelectric effect in multiferroic materials is widely studied for its fundamental interest and practical applications. The magnetoelectric effect observed for single phase materials like Cr2O3, BiFeO3, Pb(Fe0.5Nb0.5)O3is usually small. A much larger effect can be obtained in composites consisting of magnetostrictive and piezoelectric phases. This paper investigates the magnetostrictive and magnetoelectric properties of nickel ferrite Ni0.3Zn0.62Cu0.08Fe2O4- relaxor Pb(Fe0.5Nb0.5)O3bulk composites. The magnetic properties of composites shows a dependence typical of such composite materials, i.e. it consists of a dominating signal from ferrimagnetic phase (ferrite) and a weak signal from paramagnetic (antiferromagnetic) phase (relaxors). Magnetoelectric effect at room temperature was investigated as a function of static magnetic field (300-7200 Oe) and frequency (10 Hz-10 kHz) of sinusoidal modulation magnetic field. The magnetoelectric effect increase slightly before reaching a maximum at HDC= 750 Oe and then decrease. The magnetoelectric coefficient increases continuously as frequency is raised, although this increase is less pronounced in the 1-10 kHz range.

scholarly journals Bending and Position Hysteresis of Magnetic Microfibers in Nonuniform Magnetic Fields

2012 ◽  
Vol 7 (2_suppl) ◽  
pp. 155892501200702 ◽  
Author(s):  
Richard E. Groff ◽  
Meng Li ◽  
Harshwardhan Karve ◽  
Alexander Tokarev ◽  
Kostantin G. Kornev
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Magnetic Properties ◽  
Model Simulation ◽  
Ritz Method ◽  
Polymer Fibers ◽  
Qualitative Behavior ◽  
Nonuniform Field ◽  
Local Minima ◽  
Hysteresis Behavior

Magnetic microfibers are fibers that behave as a flexible paramagnetic body, for example, polymer fibers filled with superparamagnetic particles. A cantilevered magnetic microfiber will bend in response to an applied magnetic field. In a nonuniform field, generated for example by a single electromagnet or by a magnetic dipole, a magnetic microfiber displays position hysteresis as the field strength increases and decreases. This paper presents a model for determining stable shapes of a cantilevered magnetic microfiber in a nonuniform magnetic field. The model determines stable shapes by finding local minima of the potential energy using a Rayleigh-Ritz method. The model predicts the position hysteresis behavior observed in magnetic microfibers. Experimental data ware collected using two electromagnets with different geometries. The model simulation and experimental data compare well both qualitatively and quantitatively. The model will be useful for designing actuators based on magnetic microfibers and for characterizing the magnetic properties of fabricated fibers. A rigid bar model is also introduced, which captures the qualitative behavior of the fiber and illustrates the source of the position hysteresis behavior.

Magnetic phenomena

2004 ◽  
Author(s):  
Robert E. Newnham
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Dipole ◽  
Electric Charge ◽  
Dipole Moments ◽  
Magnetic Flux Density

In this chapter we deal with a number of magnetic properties and their directional dependence: pyromagnetism, magnetic susceptibility, magnetoelectricity, and piezomagnetism. In the course of dealing with these properties, two new ideas are introduced: magnetic symmetry and axial tensors. Moving electric charge generates magnetic fields and magnetization. Macroscopically, an electric current i flowing in a coil of n turns per meter produces a magnetic field H = ni amperes/meter [A/m]. On the atomic scale, magnetization arises from unpaired electron spins and unbalanced electronic orbital motion. The weber [Wb] is the basic unit of magnetic charge m. The force between two magnetic charges m1 and m2 is where r is the separation distance and μ0 (=4π×10−7 H/m) is the permeability of vacuum. In a magnetic field H, magnetic charge experiences a force F = mH [N]. North and south poles (magnetic charges) separated by a distance r create magnetic dipole moments mr [Wb m]. Magnetic dipole moments provide a convenient way of picturing the atomistic origins arising from moving electric charge. Magnetization (I) is the magnetic dipole moment per unit volume and is expressed in units of Wb m/m3 = Wb/m2. The magnetic flux density (B = I + μ0H) is also in Wb/m2 and is analogous to the electric displacement D. All materials respond to magnetic fields, producing a magnetization I = χH, and a magnetic flux density B = μH where χ is the magnetic susceptibility and μ is the magnetic permeability. Both χ and μ are in henries/m (H/m). The permeability μ = χ + μ0 and is analogous to electric permittivity. χ and μ are sometimes expressed as dimensionless quantities (x ̅ and μ ̅ and ) like the dielectric constant, where = x ̅/μ0 and = μ ̅/μ0. Other magnetic properties will be defined later in the chapter. A schematic view of the submicroscopic origins of magnetic phenomena is presented in Fig. 14.1. Most materials are diamagnetic with only a weak magnetic response induced by an applied magnetic field.

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