scholarly journals Single-molecule magnet behavior in 2,2’-bipyrimidine-bridged dilanthanide complexes

2016 ◽  
Vol 7 ◽  
pp. 126-137 ◽  
Author(s):  
Wen Yu ◽  
Frank Schramm ◽  
Eufemio Moreno Pineda ◽  
Yanhua Lan ◽  
Olaf Fuhr ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Single Molecule ◽  
Energy Barrier ◽  
Lanthanide Complexes ◽  
Hysteresis Loops ◽  
Magnetic Behavior ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Single Molecule Magnet ◽  
Homogeneous Film

A series of 2,2’-bipyrimidine-bridged dinuclear lanthanide complexes with the general formula [Ln(tmhd)3]2bpm (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionate, bpm = 2,2’-bipyrimidine, Ln = Gd(III), 1; Tb(III), 2; Dy(III), 3; Ho(III), 4 and Er(III), 5) has been synthesized and characterized. Sublimation of [Tb(tmhd)3]2bpm onto a Au(111) surface leads to the formation of a homogeneous film with hexagonal pattern, which was studied by scanning tunneling microscopy (STM). The bulk magnetic properties of all complexes have been studied comprehensively. The dynamic magnetic behavior of the Dy(III) and Er(III) compounds clearly exhibits single molecule magnet (SMM) characteristics with an energy barrier of 97 and 25 K, respectively. Moreover, micro-SQUID measurements on single crystals confirm their SMM behavior with the presence of hysteresis loops.

Regulating the single-molecule magnetic properties of phenol oxygen-bridged binuclear lanthanide complexes through the electronic and spatial effect of the substituents

2020 ◽  
Vol 7 (5) ◽  
pp. 1229-1238 ◽  
Author(s):  
Xiang-Wen Liu ◽  
Zhuo Wu ◽  
Ji-Tun Chen ◽  
Li Li ◽  
Peng Chen ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Single Molecule ◽  
Energy Barrier ◽  
Lanthanide Complexes ◽  
Spatial Effect ◽  
Bridging Ligand ◽  
Tenfold Increase ◽  
Phenol Oxygen

Series of Dy2 SMMs displayed the nearly maximum tenfold increase in energy barrier and the hysteresis temperature increased from zero to 2.5 K using the electronic and spatial effect on substituent of the bridging ligand and co-ligands.

scholarly journals Hexanuclear [Cp*Dy]6 single-molecule magnet

2020 ◽  
Vol 56 (27) ◽  
pp. 3887-3890 ◽  
Author(s):  
Jianfeng Wu ◽  
Serhiy Demeshko ◽  
Sebastian Dechert ◽  
Franc Meyer
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Magnetic Relaxation ◽  
Hysteresis Loops ◽  
High Energy ◽  
Single Molecule Magnet ◽  
High Energy Barrier

A hexanuclear cluster containing six {Cp*Dy} units shows a high energy barrier (Ueff = 561 K) for magnetic relaxation and butterfly-shaped hysteresis loops up to 4.5 K.

scholarly journals Magnetic Behavior of Luminescent Dinuclear Dysprosium and Terbium Complexes Derived from Phenoxyacetic Acid and 2,2’-Bipyridine

2019 ◽  
Vol 5 (4) ◽  
pp. 56 ◽  
Author(s):  
Mandal ◽  
Biswas ◽  
Yamashita
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Magnetic Behavior ◽  
Magnetic Study ◽  
Luminescence Spectra ◽  
Phenoxyacetic Acid ◽  
Relaxation Processes ◽  
Single Molecule Magnet ◽  
Characteristic Emission ◽  
Terbium Complexes

Two dinuclear lanthanide complexes [Dy2(L1)6(L2)2]·2EtOH (1) and [Tb2(L1)6(L2)2]·2EtOH (2) (HL1 = phenoxyacetic acid and L2 = 2,2’-bipyridine) were synthesized and the crystal structures were determined. In both complexes, the lanthanide centers are nine-coordinated and have a muffin geometry. Detailed magnetic study reveals the presence of field-induced single molecule magnet (SMM) behavior for complex 1, whereas complex 2 is non-SMM in nature. Further magnetic study with 1’, yttrium doped magnetically diluted sample of 1, disclosed the presence of Orbach and Raman relaxation processes with effective energy barrier, ∆E = 16.26 cm−1 and relaxation time, τo = 2.42 × 10−8 s. Luminescence spectra for complexes 1 and 2 in acetonitrile were studied which show characteristic emission peaks for DyIII and TbIII ions, respectively.

A linear trinuclear ferrous single molecule magnet

2018 ◽  
Vol 47 (46) ◽  
pp. 16704-16708
Author(s):  
Shihao Liu ◽  
Yi-Fei Deng ◽  
Chang'An Li ◽  
Xiaoyong Chang ◽  
Yuan-Zhu Zhang
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Effective Energy ◽  
Single Molecule Magnet ◽  
Magnetic Hysteresis Loops

A linear trinuclear ferrous [FeII3] SMM exhibited clear magnetic hysteresis loops and a significant higher effective energy barrier in comparison with its cobalt(ii) analogue.

Indirect Spin-Readout of Rare-Earth-Based Single-Molecule Magnet with Scanning Tunneling Microscopy

2021 ◽  
Vol 127 (12) ◽  
Author(s):  
Timo Frauhammer ◽  
Hongyan Chen ◽  
Timofey Balashov ◽  
Gabriel Derenbach ◽  
Svetlana Klyatskaya ◽  
...  
Keyword(s):  
Rare Earth ◽  
Scanning Tunneling Microscopy ◽  
Single Molecule ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Single Molecule Magnet

A scanning tunneling microscopy study of the electronic and spin states of bis(phthalocyaninato)terbium(iii) (TbPc2) molecules on Ag(111)

2016 ◽  
Vol 45 (42) ◽  
pp. 16644-16652 ◽  
Author(s):  
Ferdous Ara ◽  
Zhi Kun Qi ◽  
Jie Hou ◽  
Tadahiro Komeda ◽  
Keiichi Katoh ◽  
...  
Keyword(s):  
Low Temperature ◽  
Scanning Tunneling Microscopy ◽  
Single Molecule ◽  
Microscopy Study ◽  
Scanning Tunneling ◽  
Spin States ◽  
Tunneling Microscopy ◽  
Single Molecule Magnet ◽  
Scanning Tunneling Microscopy Study

In this article, we investigate a single molecule magnet bis(phthalocyaninato)terbium(iii) (TbPc2) molecule film by using low temperature STM.

Exchange-Biasing in a Dinuclear Dysprosium(III) Single-Molecule Magnet with a Large Energy Barrier for Magnetization Reversal

2019 ◽  
Author(s):  
Tian Han ◽  
Marcus J. Giansiracusa ◽  
Zi-Han Li ◽  
You-Song Ding ◽  
Nicholas F. Chilton ◽  
...  
Keyword(s):  
Single Molecule ◽  
Magnetization Reversal ◽  
Energy Barrier ◽  
Magnetic Hysteresis ◽  
Large Energy ◽  
Magnetic Studies ◽  
Bridging Ligands ◽  
Single Molecule Magnet ◽  
Exchange Biasing

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.

Correlating Blocking Temperatures in Single Molecule Magnets with Raman Relaxation

2018 ◽  
Author(s):  
Marcus J. Giansiracusa ◽  
Andreas Kostopoulos ◽  
George F. S. Whitehead ◽  
David Collison ◽  
Floriana Tuna ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Single Molecule ◽  
Energy Barrier ◽  
Thermal Relaxation ◽  
Relaxation Mechanism ◽  
Blocking Temperature ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
Key Parameter

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.

Charge Transfer Complexation Boosts Molecular Conductance Through Fermi Level Pinning

2018 ◽  
Author(s):  
Kun Wang ◽  
Andrea Vezzoli ◽  
Iain Grace ◽  
Maeve McLaughlin ◽  
Richard Nichols ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Single Molecule ◽  
Quantum Interference ◽  
Transmission Function ◽  
Scanning Tunneling ◽  
Charge Transfer Complexes ◽  
Tunneling Microscopy ◽  
Quantum Interference Effect ◽  
Single Molecule Junctions ◽  
Charge Transfer Complexation

We have used scanning tunneling microscopy to create and study single molecule junctions with thioether-terminated oligothiophene molecules. We find that the conductance of these junctions increases upon formation of charge transfer complexes of the molecules with tetracyanoethene, and that the extent of the conductance increase is greater the longer is the oligothiophene, i.e. the lower is the conductance of the uncomplexed molecule in the junction. We use non-equilibrium Green's function transport calculations to explore the reasons for this theoretically, and find that new resonances appear in the transmission function, pinned close to the Fermi energy of the contacts, as a consequence of the charge transfer interaction. This is an example of a room temperature quantum interference effect, which in this case boosts junction conductance in contrast to earlier observations of QI that result in diminished conductance.<br>

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