Magnetic dipole interactions in dysprosium ethyl sulphate - I. Susceptibility and specific heat between 20 and 1°K

1959 ◽  
Vol 252 (1269) ◽  
pp. 246-259 ◽  
Keyword(s):  
Specific Heat ◽  
Magnetic Dipole ◽  
Ground State ◽  
Optical Rotation ◽  
Dipole Interaction ◽  
Crystal Axis ◽  
Dipole Interactions ◽  
Degenerate Ground State ◽  
Magnetic Ions ◽  
Good Agreement

Measurements have been made of the magnetic susceptibility and the magnetic contributions to the specific heat of dysprosium ethyl sulphate, at temperatures between 20 and 1°K. It is shown that below about 3°K these properties, and also the earlier optical rotation measure­ments of Becquerel et al ., can be accounted for satisfactorily in terms of a doubly degenerate ground state of the magnetic ions, with spectroscopic splitting factors parallel and perpen­dicular to the crystal axis g 1 = 10.8 and g ┴ = 0, together with an unusually strong coupling between the ions arising from magnetic dipole-dipole interaction. The effect of other inter­actions is shown to be small. Because of this, and the extreme anisotropy of the g -tensor, the properties of this substance at very low temperatures (~ 0.1°K) should closely resemble those of a classical Ising model with known, dipolar forces between the ions. At temperatures above 3°K other states of the ions become populated and it is shown that the first of these lies at an energy of (23 ± 3) k , in good agreement with other experiments.

Magnetic dipole interactions in dysprosium ethyl sulphate II. Magnetic and thermal properties between 1 °K and the Curie point

1968 ◽  
Vol 306 (1486) ◽  
pp. 313-334 ◽  
Keyword(s):  
Thermal Properties ◽  
Magnetic Dipole ◽  
Dipole Interaction ◽  
Electrical Heating ◽  
Magnetic Dipole Interaction ◽  
Simple Manner ◽  
X Ray ◽  
Splitting Factor ◽  
Dipole Interactions ◽  
Good Agreement

The thermal and magnetic properties of dysprosium ethyl sulphate have been measured in the temperature range from 1 °K down to its Curie temperature of 0⋅13 ± 0⋅01 °K. Because of the extreme anisotropy of the spectroscopic splitting factor ( g II = 10⋅8, g ⊥ = 0) and the fact that magnetic dipole interaction between the ions predominates the system behaves like an Ising model. This fact allows the calculation of the magnetic and thermal properties of the system in a simple manner and good agreement is obtained with experiment. The particular properties of this salt also allow the measurement of its specific heat by each of the three methods (electrical heating, X-ray heating and relaxation heating) which may be employed at temperatures below 1 °K and excellent agreement is obtained.

SPECIFIC HEAT OF UPd2Al3

1993 ◽  
Vol 07 (01n03) ◽  
pp. 38-41 ◽  
Author(s):  
R. J. RADWAŃSKI ◽  
J. J. M. FRANSE
Keyword(s):  
Magnetic Properties ◽  
Energy Level ◽  
Specific Heat ◽  
Ground State ◽  
Exchange Parameter ◽  
State Function ◽  
Hexagonal Symmetry ◽  
Energy Level Scheme ◽  
Schottky Type ◽  
Good Agreement

Particularities in the specific heat of UPd 2 Al 3, a λ-type of peak with a maximum at 14.5 K and a Schottky-type of peak with a broad maximum at 55 K, has been attributed to the 5f-subsystem of the U atoms. The U-5f contribution has been found to be described surprisingly well within a single-ion Hamiltonian that includes the charge multipolar (CMP) interactions and the antiferromagnetic (AF) exchange interaction between the U 3+ ions. The AF exchange parameter and the full set of the CMP parameters associated with the hexagonal symmetry have been evaluated. The energy-level scheme (ELS) of this Kramers ion is constructed. The ground-state function Γ8 of the 5f 3 electrons is highly anisotropic. This state results from higher-order charge multipolar interactions. Magnetic properties resulting from this scheme including the metamagnetic-like transition at 18 T, the strongly-reduced value for the U-ion moment and its field dependence are found to be in good agreement with experimental observations.

Interaction effects in some paramagnetic salts

1955 ◽  
Vol 232 (1189) ◽  
pp. 277-289 ◽  
Keyword(s):  
Ground State ◽  
Dipole Interaction ◽  
Paramagnetic Resonance ◽  
Specific Heats ◽  
Stark Effects ◽  
Resonance Data ◽  
Pure Substances ◽  
Paramagnetic Ions ◽  
Magnetic Ions ◽  
Van Vleck

Measurements have been made of the magnetic contributions to the specific heats of several paramagnetic salts, and of diluted specimens consisting of mixed crystals of the same paramagnetic salts with isomorphous diamagnetic salts. It is shown that the specific heats can be analyzed into a contribution characteristic of the isolated paramagnetic ions, due to the splitting of the ground state by nuclear and Stark effects, and a contribution due to interactions between the magnetic ions. While the specific heats of the isolated ions agree well with the values calculated from paramagnetic resonance data, the interaction contributions are in several cases too large to be accounted for by magnetic dipole interaction between the ions. It is concluded that exchange interaction is important, even in magnetically very dilute salts, and that it is predominantly of the anisotropic type postulated by Van Vleck and Opechowski. It is shown that in some salts the Stark splitting of the ground state of the magnetic ions is very sensitive to small distortions of the crystal lattice, so that in these cases it is not possible to apply the results of measurements on diluted specimens to calculate the properties of the pure substances.

scholarly journals A perfect triangular dysprosium single-molecule magnet with virtually antiparallel Ising-like anisotropy

2020 ◽  
Vol 7 (16) ◽  
pp. 2941-2948
Author(s):  
Guang Lu ◽  
Yang Liu ◽  
Wei Deng ◽  
Guo-Zhang Huang ◽  
Yan-Cong Chen ◽  
...  
Keyword(s):  
Magnetic Dipole ◽  
Single Molecule ◽  
Ground State ◽  
Dipole Interaction ◽  
Magnetic Axis ◽  
Magnetic Dipole Interaction ◽  
Single Molecule Magnet

A perfect triangular Dy3 single-molecule magnet was reported. Each Dy(iii) magnetic axis is oriented almost normal to the plane of Dy3, and the intramolecular magnetic dipole interaction gives rise to a virtually antiparallel Ising-like ground state.

Relativistic effects in many electron hyperfine structure III. Relativistic dipole and quadrupole interaction in europium and remeasurement of the nuclear magnetic dipole moments of 151 Eu and 153 Eu

1965 ◽  
Vol 289 (1416) ◽  
pp. 114-121 ◽  
Keyword(s):  
Hyperfine Structure ◽  
Magnetic Dipole ◽  
Quadrupole Interaction ◽  
Dipole Moments ◽  
Relativistic Effects ◽  
Dipole Interaction ◽  
Triple Resonance ◽  
Limits Of Error ◽  
Good Agreement ◽  
Nuclear Magnetic

The nuclear magnetic dipole moments of 151 Eu and 153 Eu have been re-measured. The revised values (corrected for diamagnetic shielding) are: μ( 151 Eu) = 3.4630 ± 0-0006 n.m., μ( 153 Eu) = 1.5292 ± 0-0008 n.m. The ratio of the moments is μ( 151 Eu)/μ( 153 Eu) = 2.26505 ±0.00042. These results were obtained by the method of triple resonance in an atomic beam. The hyperfine structure anomaly in the ground state of the europium atom is zero within limits of error. In this special circumstance it is shown that part of the nuclear magnetic dipole interaction is explained by relativistic effects. The quadrupole interaction is treated by the same theory, and good agreement with experiment is obtained, but high precision is not claimed for the theoretical result. This theory is based on a new relativistic calculation involving the use of an effective operator acting between non-relativistic states.

Magnetic resonance studies of Dy 3+ and Er 3+ in lanthanum nicotinate dihydrate

1991 ◽  
Vol 434 (1892) ◽  
pp. 707-717 ◽  
Keyword(s):  
Single Crystals ◽  
Magnetic Dipole ◽  
Ground State ◽  
Principal Direction ◽  
Dipole Interaction ◽  
Nearest Neighbour ◽  
Paramagnetic Resonance ◽  
Magnetic Resonance Studies ◽  
Principal Value ◽  
Electron Paramagnetic

Electron paramagnetic resonance (EPR) measurements have been made on Dy 3+ and Er 3+ in lanthanum nicotinate dihydrate (LaND) single crystals, for comparison with the information described in the previous paper about single crystals of DyND and ErND. For both DyND and ErND, as for TmND, the measurements were found to be consistent with a ground state with a large amplitude of M j ═ ± J , an almost Ising-like g -matrix, and a purely magnetic dipole-dipole interaction between nearest neighbour (NN) Ln 3+ ions, where Ln is either Dy or Er. In contrast, for Ln 3+ dilutely substituted into LaND, although the g -matrix has one principal value much larger than the other two, the principal direction is different from that for LnND. EPR in crystals of LaND containing between 0.01 and 0.1 mole fraction of Ln shows that isolated ions have a g -matrix very similar to that in more dilute crystals, and NN pairs have a g -matrix similar to that for LnND and a purely magnetic dipole-dipole interaction. Hence, the Kramers ions Dy 3+ and Er 3+ are seen to exhibit the same features as were found for the non-Kramers ions Tb 3+ and Tm 3+ in the lanthanide nicotinate dihydrates.

Tuning the Magnetic Vortex State in Magnetite Nanodiscs for Remote Control of Biological Signalling

2019 ◽  
Author(s):  
Danijela Gregurec ◽  
Alexander W. Senko ◽  
Andrey Chuvilin ◽  
Pooja Reddy ◽  
Ashwin Sankararaman ◽  
...  
Keyword(s):  
Remote Control ◽  
Ion Channels ◽  
Ground State ◽  
Magnetic Particles ◽  
Colloidal Stability ◽  
Vortex State ◽  
Magnetic Vortex ◽  
Electron Holography ◽  
Dipole Interactions ◽  
Magnetite Particles

In this work, we demonstrate the application of anisotropic magnetite nanodiscs (MNDs) as transducers of torque to mechanosensory cells under weak, slowly varying magnetic fields (MFs). These MNDs possess a ground state vortex configuration of magnetic spins which affords greater colloidal stability due to eliminated dipole-dipole interactions characteristic of isotropic magnetic particles of similar size. We first predict vortex magnetization using micromagnetic stimulations in sub-micron anisotropic magnetite particles and then use electron holography to experimentally investigate the magnetization of MNDs 98–226 nm in diameter. When MNDs are coupled to MFs, they transition between vortex and in-plane magnetization allowing for the exertion of the torque on the pN scale, which is sufficient to activate mechanosensitive ion channels in cell membranes.<br>

scholarly journals Concentration-dependent oscillation of specific loss power in magnetic nanofluid hyperthermia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ji-wook Kim ◽  
Jie Wang ◽  
Hyungsub Kim ◽  
Seongtae Bae
Keyword(s):  
Magnetic Dipole ◽  
Critical Role ◽  
Dipole Interaction ◽  
Superparamagnetic Nanoparticles ◽  
Physical Reason ◽  
Strong Concentration ◽  
Magnetic Nanofluid ◽  
Specific Loss ◽  
Specific Loss Power ◽  
Magnetic Nanofluid Hyperthermia

AbstractMagnetic dipole coupling between the colloidal superparamagnetic nanoparticles (SPNPs) depending on the concentration has been paid significant attention due to its critical role in characterizing the Specific Loss Power (SLP) in magnetic nanofluid hyperthermia (MNFH). However, despite immense efforts, the physical mechanism of concentration-dependent SLP change behavior is still poorly understood and some contradictory results have been recently reported. Here, we first report that the SLP of SPNP MNFH agent shows strong concentration-dependent oscillation behavior. According to the experimentally and theoretically analyzed results, the energy competition among the magnetic dipole interaction energy, magnetic potential energy, and exchange energy, was revealed as the main physical reason for the oscillation behavior. Empirically demonstrated new finding and physically established model on the concentration-dependent SLP oscillation behavior is expected to provide biomedically crucial information in determining the critical dose of an agent for clinically safe and highly efficient MNFH in cancer clinics.

VMC CALCULATIONS OF THE GROUND STATE PROPERTIES OF NUCLEAR MATTER

2005 ◽  
Vol 14 (02) ◽  
pp. 255-267 ◽  
Author(s):  
KAAN MANİSA ◽  
ÜLFET ATAV ◽  
RIZA OGUL
Keyword(s):  
Nuclear Matter ◽  
Ground State ◽  
Nucleon Nucleon ◽  
Neutron Matter ◽  
Potential Term ◽  
Ground State Properties ◽  
Dependent Potential ◽  
Variational Monte Carlo Method ◽  
Kinetic And Potential Energies ◽  
Good Agreement

A Variational Monte Carlo method (VMC) is described for the evaluation of the ground state properties of nuclear matter. Equilibrium properties of symmetric nuclear matter and neutron matter are calculated by the described VMC method. The Urbana ν14 potential is used for the nucleon–nucleon interactions in the calculations. Three- and more-body interactions are included as a density dependent potential term. Total, kinetic and potential energies per particle are obtained for nuclear and neutron matter. Pressure values of nuclear and neutron matter are also calculated at various densities. The binding energy of nuclear matter is found to be -16.06 MeV at a saturation density of 0.16 fm -3. The results obtained are in good agreement with those obtained by various authors with different potentials and techniques.

scholarly journals THE METHOD OF INCREMENTS — A WAVEFUNCTION-BASED AB-INITIO CORRELATION METHOD FOR SOLIDS

2007 ◽  
Vol 21 (13n14) ◽  
pp. 2204-2214 ◽  
Author(s):  
BEATE PAULUS
Keyword(s):  
Experimental Data ◽  
Ab Initio ◽  
Ground State ◽  
Infinite System ◽  
Correlation Energy ◽  
Correlation Method ◽  
Many Body ◽  
Hartree Fock ◽  
The Many ◽  
Good Agreement

The method of increments is a wavefunction-based ab initio correlation method for solids, which explicitly calculates the many-body wavefunction of the system. After a Hartree-Fock treatment of the infinite system the correlation energy of the solid is expanded in terms of localised orbitals or of a group of localised orbitals. The method of increments has been applied to a great variety of materials with a band gap, but in this paper the extension to metals is described. The application to solid mercury is presented, where we achieve very good agreement of the calculated ground-state properties with the experimental data.

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