Vibrationally reduced magnetic interactions in Cu and the magnetic ordering in a magnetic field

1992 ◽  
Vol 104-107 ◽  
pp. 2109-2110 ◽  
Author(s):  
Per-Anker Lindgård
Author(s):  
Arnab Pal ◽  
Zhenjie Feng ◽  
Hao Wu ◽  
Ke Wang ◽  
Jingying Si ◽  
...  

Abstract The Haldane spin-chain compound Er2BaNiO5 has been known to possess magnetoelectric coupling below the magnetic ordering temperature. Here we report various low-temperature magnetic and magnetocaloric properties, and magnetodielectric effect above magnetic ordering temperature in this compound. The present compound displays a coexistence of conventional and inverse magnetocaloric effects with a large entropy change of 5.9 and −2.5 J/kg K, respectively. Further, it exhibits a remarkable switching between them, which can be tuned with temperature and magnetic field. In addition, evolution of two magnetic field-dependent metamagnetic transitions at 19.7 and 27.7 kOe, and their correlation with magnetocaloric switching effect, make this compound effective for potential applications. On the other hand, demonstration of intrinsic magnetodielectric effect (1.9%) near and above antiferromagnetic ordering temperature, through a moderate coupling between electric dipoles and magnetic spins, establishes this compound as a useful candidate for future research. A detailed analysis of these findings, in a framework of different magnetic interactions and magnetocrystalline anisotropies, is discussed here. Overall, these results may provide a future pathway to tune the magnetic, magnetodielectric, and magnetocaloric properties in this compound toward better application potential.


NANO ◽  
2011 ◽  
Vol 06 (01) ◽  
pp. 1-17 ◽  
Author(s):  
HUI WANG ◽  
YIFEI YU ◽  
YUBIN SUN ◽  
QIANWANG CHEN

One-dimensional (1D) chain-like structures are of special significance because of their interparticle magnetic interactions and potential applications in various fields, such as micromechanical sensors. This paper attempts to review the field of research into magnetic chains including monatomic chains and nanoparticle chains. The synthesis methods used mostly belong to one of the following categories: magnetosome chains in magnetotactic bacteria, zero-field self-assembly, magnetic field induced (MFI) assembly, template-directed synthesis, and gas phase synthesis. The potential applications of nanoparticle chains, mainly in the field of magnetic recording media, sensor, biomedicine and magnetic-field tunable photonic crystal are discussed.


Soft Matter ◽  
2019 ◽  
Vol 15 (17) ◽  
pp. 3552-3564 ◽  
Author(s):  
Dirk Romeis ◽  
Vladimir Toshchevikov ◽  
Marina Saphiannikova

Based on the dipole–dipole approach for magnetic interactions we present a comprehensive analysis of spatial rearrangement of magnetic particles under a magnetic field and its effect on the magneto-induced deformation of magneto-sensitive elastomers.


Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 120
Author(s):  
Wei Song ◽  
Yu-Zhang Fan ◽  
Yu Hua ◽  
Wei-Feng Sun

By means of magnetization treatments at ambient temperature and elevated temperatures, the nano- and micron-bismuth ferrate/low density polyethylene (BiFeO3/LDPE) dielectric composites are developed to explore the material processing method to modify the crystalline morphology, magnetic and dielectric properties. The magnetic field treatment can induce the dipole in the LDPE macromolecular chain which leads to preferred orientation of polyethylene crystal grains to the direction of the magnetization field. The surface morphology of the materials measured by atomic force microscope (AFM) implies that the LDPE macromolecular chains in BiFeO3/LDPE composites have been orderly arranged and form thicker lamellae accumulated with a larger spacing after high temperature magnetization, resulting in the increased dimension and orientation of spherulites. The residual magnetization intensities of BiFeO3/LDPE composites have been significantly improved by magnetization treatments at ambient temperature. After this magnetization at ambient temperature, the MR of nano- and micron-BiFeO3/LDPE composites approach to 4.415 × 10−3 and 0.690 × 10−3 emu/g, respectively. The magnetic moments of BiFeO3 fillers are arranged parallel to the magnetic field direction, leading to appreciable enhancement of the magnetic interactions between BiFeO3 fillers, which will inhibit the polarization of the electric dipole moments at the interface between BiFeO3 fillers and the LDPE matrix. Therefore, magnetization treatment results in the lower dielectric constant and higher dielectric loss of BiFeO3/LDPE composites. It is proven that the magnetic and dielectric properties of polymer dielectric composites can be effectively modified by the magnetization treatment in the melt blending process of preparing composites, which is expected to provide a technical strategy for developing magnetic polymer dielectrics.


2006 ◽  
Vol 972 ◽  
Author(s):  
Natasha A. Chernova ◽  
Miaomiao Ma ◽  
Jie Xiao ◽  
M. Stanley Whittingham ◽  
Jordi Cabana Jiménez ◽  
...  

AbstractThe magnetic properties of layered LiNi0.5Mn0.5O2 and NaNi0.5Mn0.5O2 cathode materials are studied using AC susceptibility and DC magnetization techniques in order to elucidate magnetic interactions within transition metal (TM) layers and between them in samples with various TM distributions. In NaNi0.5Mn0.5O2 antiferromagnetic (AF) ordering transition is found at 60 K and a spin-flop transition at high magnetic field. In LiNi0.5Mn0.5O2 obtained by ion exchange from NaNi0.5Mn0.5O2 ferrimagnetic ordering is found at around 100 K. The saturation magnetization and the hysteresis loop size of ion-exchanged compounds vary from sample to sample, which implies that the Ni2+ ions migrate upon ion exchange process. Magnetic properties of high-temperature and ion-exchanged LiNi0.5Mn0.5O2 are compared; magnetic ordering models for all compounds are proposed based on experimental results and Goodenough-Kanamori rules.


2018 ◽  
Vol 47 (34) ◽  
pp. 11888-11894 ◽  
Author(s):  
Gabriela Handzlik ◽  
Barbara Sieklucka ◽  
Dawid Pinkowicz

Anionic bridging ligands formate, cyanide and azide have been used to form cross-links in a ferrimagnetic coordination framework, resulting in competing magnetic interactions that decrease the magnetic ordering temperature and result in peculiar magnetic properties.


1970 ◽  
Vol 14 ◽  
pp. 433-440
Author(s):  
W. S. McCain ◽  
D. L. Albright ◽  
W. O. J. Boo

AbstractLattice constants were measured as a function of temperature by single crystal diffracrometry in the temperature range which includes the Néel temperature of VF2(TN= 7°K). The lattice constants of VF2(D4h14=P42m n m) were measured from room temperature down to 4.2°K. In this range rhe tetragonal c-axis contracts 0.58% from 3.2359 Å (RT) to 3.2170 Å (4.2°K). On the other hand, the a-axes show a net expansion of 0.18% from 4.8023 Å (RT) to 4.8110 Å at 4.2°K. The temperature dependence of the lattice constants can be correlated with anisotropy of exchange forces. Vanadium Ions occupy the center and corner positions of the unit cell. Strong magnetic interactions are directed parallel to the c-axis >001< with considerably weaker interactions parallel to the body diagonals >111< The relative strengths of the two exchange integrals are J >001< = 50 J >111<. As a consequence the magnetic ordering is one-dîmensional along the c-axis and the associated distortions arise from the strong magnetic interactions along this axis.


2005 ◽  
Author(s):  
Akira Satoh

We have theoretically investigated the particle orientational distribution and viscosity of a dense colloidal dispersion composed of ferromagnetic spherocylinder particles under circumstances of an applied magnetic field. The mean field approximation has been applied to take into account the magnetic interactions of the particle of interest with the other ones which belong to the neighboring clusters, besides its own cluster. The basic equation of the orientational distribution function, which is an integro-differential equation, has approximately been solved by Galerkin’s method and the method of successive approximation. Even when the magnetic interaction between particles is of the order of the thermal energy, the effect of particle-particle interactions on the orientational distribution comes to appear more significantly with increasing the volumetric fraction of particles. This effect comes to appear more significantly when the influence of the applied magnetic field is not relatively so strong compared with magnetic particle-particle interactions.


Sign in / Sign up

Export Citation Format

Share Document