Hard versus soft: zero-field dinuclear Dy(iii) oxygen bridged SMM and theoretical predictions of the sulfur and selenium analogues

2019 ◽  
Vol 48 (9) ◽  
pp. 2872-2876 ◽  
Author(s):  
Kuduva R. Vignesh ◽  
Dimitris I. Alexandropoulos ◽  
Brian S. Dolinar ◽  
Kim R. Dunbar
Keyword(s):  
Magnetic Anisotropy ◽  
Magnetic Coupling ◽  
Magnetic Behavior ◽  
Dinuclear Complexes ◽  
Zero Field ◽  
Theoretical Predictions

Structural, magnetic and CASSCF studies were used to quantify the observed magnetic behavior of two lanthanide dinuclear complexes. The effect of soft-donor atoms was probed in order to ascertain the effect of magnetic anisotropy combined with magnetic coupling in dinuclear SMMs.

scholarly journals Lanthanide Complexes with a Tripodal Nitroxyl Radical Showing Strong Magnetic Coupling

2020 ◽  
Author(s):  
Mauro Perfetti ◽  
Andrea Caneschi ◽  
Taisiya S. Sukhikh ◽  
Kira E. Vostrikova
Keyword(s):  
Single Molecule ◽  
Nitroxyl Radical ◽  
Magnetic Coupling ◽  
Magnetic Behavior ◽  
Nitroxyl Radicals ◽  
Antiferromagnetic Coupling ◽  
Zero Field ◽  
Effective Barrier ◽  
Mononuclear Complexes ◽  
Tricapped Trigonal Prism

A series of isomorphous mononuclear complexes of Ln(III) ions comprising one stable tripoidal oxazolidine nitroxyl radical were obtained in acetonitrile media starting from nitrates. The compounds, [LnRad(NO<sub>3</sub>)<sub>3</sub>] (Ln = Gd, Tb, Dy, Tm, Y; Rad = 4,4-dimethyl-2,2-bis(pyridin-2-yl)-1,3-oxazolidine-3-oxyl), have molecular structure. Their coordination polyhedron, LnO<sub>7</sub>N<sub>2</sub>, can be described as a tricapped trigonal prism with symmetry close to <i>D</i><sub>3h</sub>. The value of 23 cm<sup>-1</sup> for the antiferromagnetic coupling Gd-Rad established from the <i>DC</i> magnetic and EPR data is a record strength for the complexes of 4f-elements with nitroxyl radicals. The terbium derivative displays frequency-dependent out-of-phase signals in zero field indicating single-molecule magnetic behavior with an effective barrier of 57 cm<sup>-1</sup>.

scholarly journals Lanthanide Complexes with a Tripodal Nitroxyl Radical Showing Strong Magnetic Coupling

2020 ◽  
Author(s):  
Mauro Perfetti ◽  
Andrea Caneschi ◽  
Taisiya S. Sukhikh ◽  
Kira E. Vostrikova
Keyword(s):  
Single Molecule ◽  
Nitroxyl Radical ◽  
Magnetic Coupling ◽  
Magnetic Behavior ◽  
Nitroxyl Radicals ◽  
Antiferromagnetic Coupling ◽  
Zero Field ◽  
Effective Barrier ◽  
Mononuclear Complexes ◽  
Tricapped Trigonal Prism

A series of isomorphous mononuclear complexes of Ln(III) ions comprising one stable tripoidal oxazolidine nitroxyl radical were obtained in acetonitrile media starting from nitrates. The compounds, [LnRad(NO<sub>3</sub>)<sub>3</sub>] (Ln = Gd, Tb, Dy, Tm, Y; Rad = 4,4-dimethyl-2,2-bis(pyridin-2-yl)-1,3-oxazolidine-3-oxyl), have molecular structure. Their coordination polyhedron, LnO<sub>7</sub>N<sub>2</sub>, can be described as a tricapped trigonal prism with symmetry close to <i>D</i><sub>3h</sub>. The value of 23 cm<sup>-1</sup> for the antiferromagnetic coupling Gd-Rad established from the <i>DC</i> magnetic and EPR data is a record strength for the complexes of 4f-elements with nitroxyl radicals. The terbium derivative displays frequency-dependent out-of-phase signals in zero field indicating single-molecule magnetic behavior with an effective barrier of 57 cm<sup>-1</sup>.

scholarly journals Lanthanide Complexes with a Tripodal Nitroxyl Radical Showing Strong Magnetic Coupling

2020 ◽  
Author(s):  
Mauro Perfetti ◽  
Andrea Caneschi ◽  
Taisiya S. Sukhikh ◽  
Kira E. Vostrikova
Keyword(s):  
Single Molecule ◽  
Nitroxyl Radical ◽  
Magnetic Coupling ◽  
Magnetic Behavior ◽  
Nitroxyl Radicals ◽  
Antiferromagnetic Coupling ◽  
Zero Field ◽  
Effective Barrier ◽  
Mononuclear Complexes ◽  
Tricapped Trigonal Prism

A series of isomorphous mononuclear complexes of Ln(III) ions comprising one stable tripoidal oxazolidine nitroxyl radical were obtained in acetonitrile media starting from nitrates. The compounds, [LnRad(NO<sub>3</sub>)<sub>3</sub>] (Ln = Gd, Tb, Dy, Tm, Y; Rad = 4,4-dimethyl-2,2-bis(pyridin-2-yl)-1,3-oxazolidine-3-oxyl), have molecular structure. Their coordination polyhedron, LnO<sub>7</sub>N<sub>2</sub>, can be described as a tricapped trigonal prism with symmetry close to <i>D</i><sub>3h</sub>. The value of 23 cm<sup>-1</sup> for the antiferromagnetic coupling Gd-Rad established from the <i>DC</i> magnetic and EPR data is a record strength for the complexes of 4f-elements with nitroxyl radicals. The terbium derivative displays frequency-dependent out-of-phase signals in zero field indicating single-molecule magnetic behavior with an effective barrier of 57 cm<sup>-1</sup>.

Spin-Lattice Coupling and Peculiarities of Magnetic Behavior of Ferrimagnetic Ludwigites Mn0.52+M1.52+Mn3+BO5(M=Cu, Ni)

2015 ◽  
Vol 233-234 ◽  
pp. 133-136 ◽  
Author(s):  
Leonard Bezmaternykh ◽  
Evgeniya Moshkina ◽  
Evgeniy Eremin ◽  
Maxim Molokeev ◽  
Nikita Volkov ◽  
...  
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Magnetic Anisotropy ◽  
Single Crystals ◽  
Magnetic Behavior ◽  
Temperature Hysteresis ◽  
Spin Lattice ◽  
Field Magnetization ◽  
Lattice Coupling

Temperature-field and orientational magnetization dependences of single crystals were measured. Both samples demonstrate significant field-depending temperature hysteresis and low-temperature counter field magnetization. The correlation of orientational dependences of these effects and magnetic anisotropy is analyzed; the role of spin-lattice interactions is discussed.

Modulation of the coordination environment: a convenient approach to tailor magnetic anisotropy in seven coordinate Co(ii) complexes

2016 ◽  
Vol 52 (4) ◽  
pp. 753-756 ◽  
Author(s):  
Mamon Dey ◽  
Snigdha Dutta ◽  
Bipul Sarma ◽  
Ramesh Ch. Deka ◽  
Nayanmoni Gogoi
Keyword(s):  
Magnetic Anisotropy ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Coordination Environment ◽  
Zero Field Splitting Parameter ◽  
Convenient Approach ◽  
Splitting Parameter ◽  
Remarkable Deviation

Subtle modulation of the coordination environment in seven coordinate Co(ii) complexes leads to a remarkable deviation in the axial zero field splitting parameter (D) in a predictable fashion.

On the magnetic coupling in asymmetric bridged Cu(II) dinuclear complexes: The influence of substitutions on the carboxylato group

2011 ◽  
Vol 375 (1) ◽  
pp. 166-172 ◽  
Author(s):  
Igor Negodaev ◽  
Coen de Graaf ◽  
Rosa Caballol ◽  
V.V. Lukov
Keyword(s):  
Magnetic Coupling ◽  
Dinuclear Complexes

Surface Effects on the Magnetic Behavior of Nanocrystalline Nickel Ferrites: The Effect of Surface Roughness and Dilution

2005 ◽  
Vol 877 ◽  
Author(s):  
H. Nathani ◽  
R.D.K. Misra ◽  
W.F. Egelhoff
Keyword(s):  
Surface Roughness ◽  
Nickel Ferrite ◽  
Magnetic Measurements ◽  
Magnetic Behavior ◽  
Magnetic Data ◽  
Zero Field ◽  
Nanocrystalline Nickel ◽  
Polyethylene Matrix ◽  
Dilution Effects ◽  
Field Cooling

AbstractThe paper describes the surface roughness and dilution effects on the magnetic behavior of nanocrystalline nickel ferrites studied by SQUID magnetometer. Two different kinds of measurements were performed: (a) zero-field cooling (ZFC) and field cooling (FC) magnetization versus temperature and (b) magnetization as a function of the applied field. The analysis of magnetic measurements indicate that while the superparamagnetic behavior is retained by nanocrystalline ferrites of different surface roughness (0.8-1.8 nm) at 300K, the hysteresis loop at 2K becomes non-squared and the coercivity increases with increase in surface roughness. This behavior is discussed in terms of broken bonds and degree of surface spin disorder. In diluted dispersion systems containing 10-40% nickel ferrite in a polyethylene matrix, the interparticle attractions continue to be dominant even when the concentration of nickel ferrite is 10 wt.% in the diluted system. The general magnetic behavior of diluted dispersion system is similar to the undiluted system; however, coercivity, remanence, and saturation magnetization are altered. These changes in the magnetic data are ascribed to magnetization interactions that encourage flux closure configuration.

scholarly journals Data-driven studies of magnetic two-dimensional materials

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Trevor David Rhone ◽  
Wei Chen ◽  
Shaan Desai ◽  
Steven B. Torrisi ◽  
Daniel T. Larson ◽  
...  
Keyword(s):  
Machine Learning ◽  
Dft Calculations ◽  
Density Functional ◽  
Magnetic Coupling ◽  
Magnetic Ordering ◽  
Magnetic Behavior ◽  
Data Driven ◽  
Two Dimensional ◽  
Computationally Efficient ◽  
Data Driven Approach

Abstract We use a data-driven approach to study the magnetic and thermodynamic properties of van der Waals (vdW) layered materials. We investigate monolayers of the form $$\hbox {A}_2\hbox {B}_2\hbox {X}_6$$ A 2 B 2 X 6 , based on the known material $$\hbox {Cr}_2\hbox {Ge}_2\hbox {Te}_6$$ Cr 2 Ge 2 Te 6 , using density functional theory (DFT) calculations and machine learning methods to determine their magnetic properties, such as magnetic order and magnetic moment. We also examine formation energies and use them as a proxy for chemical stability. We show that machine learning tools, combined with DFT calculations, can provide a computationally efficient means to predict properties of such two-dimensional (2D) magnetic materials. Our data analytics approach provides insights into the microscopic origins of magnetic ordering in these systems. For instance, we find that the X site strongly affects the magnetic coupling between neighboring A sites, which drives the magnetic ordering. Our approach opens new ways for rapid discovery of chemically stable vdW materials that exhibit magnetic behavior.

Influence of the Coligand onto the Magnetic Anisotropy and the Magnetic Behavior of One-Dimensional Coordination Polymers

2020 ◽  
Vol 59 (13) ◽  
pp. 8971-8982 ◽  
Author(s):  
Aleksej Jochim ◽  
Thomas Lohmiller ◽  
Michał Rams ◽  
Michael Böhme ◽  
Magdalena Ceglarska ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Coordination Polymers ◽  
Magnetic Behavior ◽  
One Dimensional

scholarly journals Effects of High Magnetic Fields on Phase Transformations in Amorphous Nd2Fe14B

2019 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Michael Kesler ◽  
Brandt Jensen ◽  
Lin Zhou ◽  
Olena Palasyuk ◽  
Tae-Hoon Kim ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Melt Spinning ◽  
Magnetic Behavior ◽  
Phase Evolution ◽  
High Magnetic Fields ◽  
Phase Identification ◽  
Zero Field ◽  
Transmission Electron ◽  
Size And Morphology ◽  
Applied Fields

We briefly summarize the results from a set of experiments designed to demonstrate the effects of high magnetic fields applied during thermal annealing of amorphous Nd2Fe14B produced through melt-spinning. A custom-built differential scanning calorimeter was used to determine the crystallization temperatures in zero-field and in applied fields of 20 kOe and 90 kOe, which guided subsequent heat treatments to evaluate phase evolution. X-ray diffraction was used for phase identification and transmission electron microscopy was employed for observation of the crystallite size and morphology. Magnetization measurements were also used to evaluate the resulting magnetic phases after thermomagnetic processing. While the applied magnetic fields do not appear to affect the crystallization temperature, significant effects on the kinetics of phase evolution are observed and correlated strongly to the magnetic behavior.

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