scholarly journals Magnetic interactions and spin dynamics in the bond-disordered pyrochlore fluoride NaCaCo2F7

2019 ◽  
Vol 99 (15) ◽  
Author(s):  
J. Zeisner ◽  
S. A. Bräuninger ◽  
L. Opherden ◽  
R. Sarkar ◽  
D. I. Gorbunov ◽  
...  
Keyword(s):  
Spin Dynamics ◽  
Magnetic Interactions

scholarly journals Spin dynamics and magnetic interactions of Mn dopants in the topological insulatorBi2Te3

2016 ◽  
Vol 94 (12) ◽  
Author(s):  
S. Zimmermann ◽  
F. Steckel ◽  
C. Hess ◽  
H. W. Ji ◽  
Y. S. Hor ◽  
...  
Keyword(s):  
Spin Dynamics ◽  
Magnetic Interactions

scholarly journals Study of the influence of properties of dusty ferromagnetic additives on the increase of cement activity

2020 ◽  
Vol 166 ◽  
pp. 06002
Author(s):  
Serhiy Sakhno ◽  
Lyudmyla Yanova ◽  
Olena Pischikova ◽  
Serhii Chukharev
Keyword(s):  
Spin Dynamics ◽  
Construction Materials ◽  
Strength Characteristics ◽  
Magnetic Interactions ◽  
Magnetic Characteristics ◽  
Practical Implementation ◽  
Long Term Impact ◽  
And Control ◽  
Influence Of Properties

Sustainable development of construction materials is directly related to research on the processes of hydration of binders. Builders need better types of cement, with lower cost and energy consumption in production. The development of spin chemistry methods allows us to consider the processes of hydration and structure formation of binders from the spin state of the elements involved in chemical reactions. Magnetic interactions have a significant effect on the spin dynamics and the control of the spin multiplicity of radical pairs. The practical implementation of magnetic effects on a binder can be carried out in various ways. However, a long-term impact can be achieved only by introducing ferromagnetic substances into the binders. In the paper presented the results of a study of the influence of the characteristics of finely dispersed powdered ferromagnetic additives on the strength characteristics of cement. Ferromagnetic additives regulate the behavior of the reactants during rotation during the hydration of the binders due to magnetic interactions and control the reactivity of the chemical reaction. A comparative analysis revealed that it is most expedient to use as powdery ferromagnetic additives are the waste from mining and processing enterprises of the Krivorozhsky field. The work investigated the magnetic and dispersed characteristics of 12 different dust. The experiments showed that the origin of dust and the method of their capture are determined their magnetic characteristics. Preparation of samples with the dust and determination of the strength characteristics of cement were carried out by standard methods. The results obtained made it possible to reveal the laws of the effect of the dispersed and magnetic properties of various dust on the degree of activation of binders.

scholarly journals Relationship between the Coordination Geometry and Spin Dynamics of Dysprosium(III) Heteroleptic Triple-Decker Complexes

2019 ◽  
Vol 5 (4) ◽  
pp. 65 ◽  
Author(s):  
Tetsu Sato ◽  
Satoshi Matsuzawa ◽  
Keiichi Katoh ◽  
Brian K. Breedlove ◽  
Masahiro Yamashita
Keyword(s):  
Single Molecule ◽  
Magnetic Relaxation ◽  
Spin Dynamics ◽  
Twist Angle ◽  
Magnetic Interactions ◽  
Relaxation Processes ◽  
Coordination Geometry ◽  
Single Molecule Magnets ◽  
Spin Lattice ◽  
The Relationship

When using single molecule magnets (SMMs) in spintronics devices, controlling the quantum tunneling of the magnetization (QTM) and spin-lattice interactions is important. To improve the functionality of SMMs, researchers have explored the effects of changing the coordination geometry of SMMs and the magnetic interactions between them. Here, we report on the effects of the octa-coordination geometry on the magnetic relaxation processes of dinuclear dysprosium(III) complexes in the low-temperature region. Mixed ligand dinuclear Dy3+ triple-decker complexes [(TPP)Dy(Pc)Dy(TPP)] (1), which have crystallographically equivalent Dy3+ ions, and [(Pc)Dy(Pc)Dy(TPP)] (2), which have non-equivalent Dy3+ ions, (Pc2− = phthalocyaninato; TPP2− = tetraphenylporphyrinato), undergo dual magnetic relaxation processes. This is due to the differences in the ground states due to the twist angle (φ) between the ligands. The relationship between the off-diagonal terms and the dual magnetic relaxation processes that appears due to a deviation from D4h symmetry is discussed.

scholarly journals Development of short and long-range magnetic order in the double perovskite based frustrated triangular lattice antiferromagnet Ba$$_{2}$$MnTeO$$_{6}$$

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Khatua ◽  
T. Arh ◽  
Shashi B. Mishra ◽  
H. Luetkens ◽  
A. Zorko ◽  
...  
Keyword(s):  
Triangular Lattice ◽  
Degrees Of Freedom ◽  
Spin Dynamics ◽  
Muon Spin ◽  
Magnetic Ordering ◽  
Double Exchange ◽  
Double Perovskite ◽  
Magnetic Interactions ◽  
Spin Frustration ◽  
Ordered State

AbstractFrustrated magnets based on oxide double perovskites offer a viable ground wherein competing magnetic interactions, macroscopic ground state degeneracy and complex interplay between emergent degrees of freedom can lead to correlated quantum phenomena with exotic excitations highly relevant for potential technological applications. By local-probe muon spin relaxation ($$\mu$$ μ SR) and complementary thermodynamic measurements accompanied by first-principles calculations, we here demonstrate novel electronic structure and magnetic phases of Ba$$_{2}$$ 2 MnTeO$$_{6}$$ 6 , where Mn$$^{2+}$$ 2 + ions with S = 5/2 spins constitute a perfect triangular lattice. Magnetization results evidence the presence of strong antiferromagnetic interactions between Mn$$^{2+}$$ 2 + spins and a phase transition at $$T_{N}$$ T N = 20 K. Below $$T_{N}$$ T N , the specific heat data show antiferromagnetic magnon excitations with a gap of 1.4 K, which is due to magnetic anisotropy. $$\mu$$ μ SR reveals the presence of static internal fields in the ordered state and short-range spin correlations high above $$T_{N}$$ T N . It further unveils critical slowing-down of spin dynamics at $$T_{N}$$ T N and the persistence of spin dynamics even in the magnetically ordered state. Theoretical studies infer that Heisenberg interactions govern the inter- and intra-layer spin-frustration in this compound. Our results establish that the combined effect of a weak third-nearest-neighbour ferromagnetic inter-layer interaction (owing to double-exchange) and intra-layer interactions stabilizes a three-dimensional magnetic ordering in this frustrated magnet.

scholarly journals Discovery and characterization of a new type of domain wall in a row-wise antiferromagnet

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jonas Spethmann ◽  
Martin Grünebohm ◽  
Roland Wiesendanger ◽  
Kirsten von Bergmann ◽  
André Kubetzka
Keyword(s):  
Domain Wall ◽  
Spin Structure ◽  
Domain Walls ◽  
Spin Dynamics ◽  
Magnetic Interactions ◽  
Theoretical Modelling ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
New Type ◽  
Dynamics Simulations

AbstractAntiferromagnets have recently moved into the focus of application-related research, with the perspective to use them in future spintronics devices. At the same time the experimental determination of the detailed spin texture remains challenging. Here we use spin-polarized scanning tunneling microscopy to investigate the spin structure of antiferromagnetic domain walls. Comparison with spin dynamics simulations allows the identification of a new type of domain wall, which is a superposition state of the adjacent domains. We determine the relevant magnetic interactions and derive analytical formulas. Our experiments show a pathway to control the number of domain walls by boundary effects, and demonstrate the possibility to change the position of domain walls by interaction with movable adsorbed atoms. The knowledge about the exact spin structure of the domain walls is crucial for an understanding and theoretical modelling of their properties regarding, for instance, dynamics, response in transport experiments, and manipulation.

Computational of localized spinwaves at a stepped surface of an antiferromagnetic metallic monoxide

2020 ◽  
Vol 34 (09) ◽  
pp. 2050080
Author(s):  
Farid Chelli ◽  
Boualem Bourahla ◽  
Antoine Khater
Keyword(s):  
Spin Dynamics ◽  
Chemical Species ◽  
Magnetic Coupling ◽  
Magnetic Interactions ◽  
Surface Zone ◽  
Experimental Conditions ◽  
Complete Representation ◽  
Rocksalt Structure ◽  
Spin Excitations ◽  
Stepped Surface

We investigate the spin excitations at the (001) stepped surface in semi-infinite antiferromagnetic monoxide cubic rocksalt structure of the type MO, made up from compounds of metal cations M[Formula: see text] and oxygen anions O[Formula: see text]. At the surface, of semi-infinite monoxide lattices, the translation symmetry along the direction normal to surface zone is broken. Therefore, significant changes of spin dynamics and magnetic properties are expected at the surface in question. The dependence on properties comes from the geometrical arrangement of the chemical species present at the surface, leading to appearing localized antiferromagnetic spin modes. The spin excitations and the amplitudes of precession due to variations in exchange and superexchange parameters generated by the stepped surface zone are simulated and analyzed, for different cases that can be considered, from softening to hardening effects. The technical formalism of matching method, associated to Green functions, is employed to determine the magnonic densities of states, for the spin components of the individual sites that constitute a complete representation of the stepped surface domain boundaries. Our results shown that the calculated localized spin modes are sensitive to the magnetic coupling between different spin sites at the surface. The simulated cases yield criteria under certain experimental conditions, as regards the interpretation of the measurements of the magnetic interactions in the surface zone and its boundaries. However, for a given material, the spin surfaces corresponding to different orientations are not equivalents and, in particular, they do not have the same stability.

scholarly journals Proposal to use superparamagnetic nanoparticles to test the role of cryptochrome in magnetoreception

2018 ◽  
Vol 15 (147) ◽  
pp. 20180587 ◽  
Author(s):  
Susannah Bourne Worster ◽  
P. J. Hore
Keyword(s):  
Spin Relaxation ◽  
Spin Dynamics ◽  
Spin Correlation ◽  
Neuronal Firing ◽  
Magnetic Sensors ◽  
Superparamagnetic Nanoparticles ◽  
Magnetic Interactions ◽  
Electron Spin Relaxation ◽  
Primary Sensor ◽  
Dynamics Simulations

Evidence is accumulating to support the hypothesis that some animals use light-induced radical pairs to detect the direction of the Earth's magnetic field. Cryptochrome proteins seem to be involved in the sensory pathway but it is not yet clear if they are the magnetic sensors: they could, instead, play a non-magnetic role as signal transducers downstream of the primary sensor. Here we propose an experiment with the potential to distinguish these functions. The principle is to use superparamagnetic nanoparticles to disable any magnetic sensing role by enhancing the electron spin relaxation of the radicals so as to destroy their spin correlation. We use spin dynamics simulations to show that magnetoferritin, a synthetic, protein-based nanoparticle, has the required properties. If cryptochrome is the primary sensor, then it should be inactivated by a magnetoferritin particle placed 12–16 nm away. This would prevent a bird from using its magnetic compass in behavioural tests and abolish magnetically sensitive neuronal firing in the retina. The key advantage of such an experiment is that any signal transduction role should be completely unaffected by the tiny magnetic interactions (≪ k B T ) required to enhance the spin relaxation of the radical pair.

Aspects of spin dynamics and magnetic interactions

1999 ◽  
Vol 200 (1-3) ◽  
pp. 148-166 ◽  
Author(s):  
V.P Antropov ◽  
B.N Harmon ◽  
A.N Smirnov
Keyword(s):  
Spin Dynamics ◽  
Magnetic Interactions

Magnetic Interactions In YbBa 2Cu 3O x (x = 7.0, 6.0) From 170Yb 3+ Mössbauer Measurements

1995 ◽  
Vol 5 (4) ◽  
pp. 501-515 ◽  
Author(s):  
J. A. Hodges ◽  
P. Bonville ◽  
P. Imbert ◽  
A. Pinatel-Phillipot
Keyword(s):  
Magnetic Interactions ◽  
Mössbauer Measurements
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