Single-molecule magnet Fe9 supramolecular dimers: a theoretical approach to intramolecular and intermolecular exchange interactions

2009 ◽  
pp. 4363 ◽  
Author(s):  
Silvia Gómez-Coca ◽  
Eliseo Ruiz ◽  
Jens Kortus
2016 ◽  
Vol 45 (18) ◽  
pp. 7642-7649 ◽  
Author(s):  
Diana Visinescu ◽  
Maria-Gabriela Alexandru ◽  
Augustin M. Madalan ◽  
Ie-Rang Jeon ◽  
Corine Mathonière ◽  
...  

Four 3d–4f–4(5)d heterotrimetallic complexes, [L2CuLn(H2O)5(μ-NC)M(CN)7], were obtained from the association of the binuclear 3d–4f complexes and {MV(CN)8}3− metalloligands.


2018 ◽  
Vol 4 (4) ◽  
pp. 48
Author(s):  
Dimitris Alexandropoulos ◽  
Alysha Alaimo ◽  
Di Sun ◽  
Theocharis Stamatatos

A new {Dy5} cluster compound has been synthesized and structurally characterized from the initial use of the Schiff base ligand N-naphthalidene-2-amino-5-chlorophenol (nacpH2) in coordination chemistry. The 1:1 reaction between Dy(hpd)3∙2H2O and nacpH2, in a solvent mixture comprising CH2Cl2 and MeOH, afforded orange crystals of [Dy5(OH)2(hpd)3(nacp)5(MeOH)5] (1) in 70% yield, where hpd− is the anion of 3,5-heptadione. The {Dy5} complex can be described as two vertical {Dy3(μ3-OH)}8+ triangles sharing a common vertex; such a metal topology is unprecedented in 4f-metal cluster chemistry. Direct current (dc) magnetic susceptibility studies revealed the presence of some weak ferromagnetic exchange interactions between the five DyIII ions at low temperatures. Alternating current (ac) magnetic susceptibility measurements at zero applied dc field showed that complex 1∙3MeOH∙CH2Cl2 exhibits temperature- and frequency-dependent out-of-phase signals below ~20 K, characteristics of a single-molecule magnet (SMM). The resulting relaxation times were used to construct an Arrhenius-type plot and determine an effective energy barrier, Ueff, of 100 K for the magnetization reversal. The application of a small dc field of 200 Oe resulted in the surpassing of the quantum tunneling process and subsequently the increase of the Ueff to a value of 170 K. The reported results are part of a long-term program aiming at the preparation of structurally and magnetically interesting lanthanide complexes bearing various Schiff base chelating/bridging ligands.


2020 ◽  
Vol 7 (2) ◽  
pp. 447-454 ◽  
Author(s):  
Yin-Shan Meng ◽  
Yu-Sen Qiao ◽  
Mu-Wen Yang ◽  
Jin Xiong ◽  
Tao Liu ◽  
...  

In this work, we investigated the magnetic anisotropy and the influence of weak exchange interactions on the magnetic relaxations of a triangular type dysprosium single-molecule magnet.


2022 ◽  
Author(s):  
Michał Magott ◽  
Maria Brzozowska ◽  
Stanisław Baran ◽  
Veacheslav Vieru ◽  
Dawid Pinkowicz

The best performing molecular nanomagnets are currently designed by carefully arranging p-element donor atoms (usually carbon, nitrogen and/or oxygen) around the central magnetic ion. Inspired by the structure of the hardest intermetallic magnet SmCo5, we have demonstrated a nanomagnetic molecule where the central lanthanide (Ln) ion Er is coordinated solely by three transition metal (TM) ions in a perfectly trigonal planar fashion. The molecule [Er(ReCp2)3] (ErRe3) constitutes the first example of a molecular nanomagnet (MNM; or single molecule magnet SMM) with unsupported Ln-TM bonds and paves the way towards molecular intermetallics with strong direct magnetic exchange interactions. Such interactions are believed to be crucial for quenching the quantum tunneling of magnetization which limits the application of Ln-SMMs as sub-nanometer magnetic memory units.


2012 ◽  
Vol 190 ◽  
pp. 490-493
Author(s):  
Victor V. Kostyuchenko

At the present time two models can more or less describe the magnetic properties ofNi4Mo12. The rst one is based on the assumption of essential role of non-Heisenberg exchangeinteractions. The key feature of the second model is the symmetry breaking of exchange inter-actions. The present work is focused on the forecasting power of these spin models. Mechanismresponsible for non-Heisenberg exchange interactions is the same as mechanism resulting in in-teraction of spin chirality with external magnetic eld. An additional level splitting in magnetic eld can be observed in this case. The symmetry breaking of exchange interactions inevitablyleads to nonzero toroidal moment and related to it magnetoelectric phenomena.


2019 ◽  
Author(s):  
Tian Han ◽  
Marcus J. Giansiracusa ◽  
Zi-Han Li ◽  
You-Song Ding ◽  
Nicholas F. Chilton ◽  
...  

A dichlorido-bridged dinuclear dysprosium(III) single-molecule magnet [Dy<sub>2</sub>L<sub>2</sub>(<i>µ</i>-Cl)<sub>2</sub>(THF)<sub>2</sub>] has been made using a diamine-bis(phenolate) ligand, H<sub>2</sub>L. Magnetic studies show an energy barrier for magnetization reversal (<i>U</i><sub>eff</sub>) around 1000 K. Exchange-biasing effect is clearly seen in magnetic hysteresis with steps up to 4 K. <i>Ab</i> initio calculations exclude the possibility of pure dipolar origin of this effect leading to the conclusion that super-exchange <i>via</i> the chloride bridging ligands is important.


2018 ◽  
Author(s):  
Marcus J. Giansiracusa ◽  
Andreas Kostopoulos ◽  
George F. S. Whitehead ◽  
David Collison ◽  
Floriana Tuna ◽  
...  

We report a six coordinate DyIII single-molecule magnet<br>(SMM) with an energy barrier of 1110 K for thermal relaxation of<br>magnetization. The sample shows no retention of magnetization<br>even at 2 K and this led us to find a good correlation between the<br>blocking temperature and the Raman relaxation regime for SMMs.<br>The key parameter is the relaxation time (𝜏<sub>switch</sub>) at the point where<br>the Raman relaxation mechanism becomes more important than<br>Orbach.


Author(s):  
Fabrice Pointillart ◽  
Bertrand Lefeuvre ◽  
Carlo Andrea Mattei ◽  
Jessica Flores Gonzalez ◽  
Frédéric Gendron ◽  
...  

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