scholarly journals Magnetic hysteresis up to 80 kelvin in a dysprosium metallocene single-molecule magnet

Science ◽  
2018 ◽  
Vol 362 (6421) ◽  
pp. 1400-1403 ◽  
Author(s):  
Fu-Sheng Guo ◽  
Benjamin M. Day ◽  
Yan-Cong Chen ◽  
Ming-Liang Tong ◽  
Akseli Mansikkamäki ◽  
...  
Keyword(s):  
Single Molecule ◽  
Magnetic Hysteresis ◽  
Information Storage ◽  
Blocking Temperature ◽  
Wave Number ◽  
Magnetic Memory ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
Chemical Strategy ◽  
Lower Size

Single-molecule magnets (SMMs) containing only one metal center may represent the lower size limit for molecule-based magnetic information storage materials. Their current drawback is that all SMMs require liquid-helium cooling to show magnetic memory effects. We now report a chemical strategy to access the dysprosium metallocene cation [(CpiPr5)Dy(Cp*)]+ (CpiPr5, penta-iso-propylcyclopentadienyl; Cp*, pentamethylcyclopentadienyl), which displays magnetic hysteresis above liquid-nitrogen temperatures. An effective energy barrier to reversal of the magnetization of Ueff = 1541 wave number is also measured. The magnetic blocking temperature of TB = 80 kelvin for this cation overcomes an essential barrier toward the development of nanomagnet devices that function at practical temperatures.

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.

Recent advances in lanthanide coordination polymers and clusters with magnetocaloric effect or single-molecule magnet behavior

2021 ◽  
Author(s):  
Jun-Jie Hu ◽  
Yan Peng ◽  
Sui-Jun Liu ◽  
He-Rui Wen
Keyword(s):  
Quantum Computing ◽  
Low Temperature ◽  
Magnetocaloric Effect ◽  
Coordination Polymers ◽  
Single Molecule ◽  
Information Storage ◽  
Lanthanide Ions ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
Lanthanide Coordination Polymers

The molecular magnetorefrigerant materials for low-temperature magnetic refrigeration and single-molecule magnets for high-density information storage and quantum computing have received extensive attention from chemists and magnetic experts. Lanthanide ions with...

scholarly journals Pseudo-Tetrahedral vs Pseudo-Octahedral ErIII Single Molecule Magnets and the 'Disruptive' Role of Coordinated TEMPO Radicals

2021 ◽  
Author(s):  
Maria Brzozowska ◽  
Gabriela Handzlik ◽  
Katarzyna Kurpiewska ◽  
Mikołaj Zychowicz ◽  
Dawid Pinkowicz
Keyword(s):  
Single Molecule ◽  
High Performance ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Relaxation Mechanism ◽  
Magnetic Memory ◽  
Single Molecule Magnets ◽  
Magnetization Relaxation ◽  
Tempo Radical

Erbium(III) complexes are the most interesting candidates for high-performance single molecule magnets (SMMs) just after dysprosium(III). Herein, we thoroughly explore the underrepresented class of neutral pseudo-tetrahedral erbium(III) SMMs and demonstrate their exceptional slow magnetization dynamics controlled by the Raman relaxation mechanism and the molecular magnetic memory effect in the form of a waist-restricted magnetic hysteresis loop. The influence of the coordinated TEMPO radical on the slow magnetization relaxation performance is also demonstrated and discussed.<br>

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.

Enhancing the magnetic blocking temperature and magnetic coercivity of {CrIII2LnIII2} single-molecule magnets via bridging ligand modification

2016 ◽  
Vol 52 (73) ◽  
pp. 10976-10979 ◽  
Author(s):  
Stuart K. Langley ◽  
Daniel P. Wielechowski ◽  
Boujemaa Moubaraki ◽  
Keith S. Murray
Keyword(s):  
Relaxation Time ◽  
Single Molecule ◽  
Magnetic Relaxation ◽  
Magnetic Hysteresis ◽  
Blocking Temperature ◽  
Single Molecule Magnets ◽  
Ligand Modification ◽  
Bridging Ligand

Replacing bridging benzoate ligands with 2-chloro-4,5-fluorobenzoate in a family of {CrIII2LnIII2} (Ln = Tb, Dy and Ho) single-molecule magnets results in significant improvements in magnetic relaxation time, magnetic hysteresis blocking temperature and magnetic coercivity.

scholarly journals Pseudo-Tetrahedral vs Pseudo-Octahedral ErIII Single Molecule Magnets and the 'Disruptive' Role of Coordinated TEMPO Radicals

2021 ◽  
Author(s):  
Maria Brzozowska ◽  
Gabriela Handzlik ◽  
Katarzyna Kurpiewska ◽  
Mikołaj Zychowicz ◽  
Dawid Pinkowicz
Keyword(s):  
Single Molecule ◽  
High Performance ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Relaxation Mechanism ◽  
Magnetic Memory ◽  
Single Molecule Magnets ◽  
Magnetization Relaxation ◽  
Tempo Radical

Erbium(III) complexes are the most interesting candidates for high-performance single molecule magnets (SMMs) just after dysprosium(III). Herein, we thoroughly explore the underrepresented class of neutral pseudo-tetrahedral erbium(III) SMMs and demonstrate their exceptional slow magnetization dynamics controlled by the Raman relaxation mechanism and the molecular magnetic memory effect in the form of a waist-restricted magnetic hysteresis loop. The influence of the coordinated TEMPO radical on the slow magnetization relaxation performance is also demonstrated and discussed.<br>

scholarly journals A large barrier single-molecule magnet without magnetic memory

2019 ◽  
Vol 48 (29) ◽  
pp. 10795-10798 ◽  
Author(s):  
Marcus J. Giansiracusa ◽  
Susan Al-Badran ◽  
Andreas K. Kostopoulos ◽  
George F. S. Whitehead ◽  
David Collison ◽  
...  
Keyword(s):  
Single Molecule ◽  
Energy Barrier ◽  
Magnetic Hysteresis ◽  
Thermal Relaxation ◽  
Magnetic Memory ◽  
Single Molecule Magnet

We report a six coordinate DyIII single-molecule magnet (SMM) with an energy barrier of 1110 K for thermal relaxation of magnetization, but no magnetic hysteresis above 2 K.

Seeking Magneto-Structural Correlations in Easily Tailored Pentagonal Bipyramid Dy(III) Single-Ion Magnets

2019 ◽  
Author(s):  
Guo-Zhang Huang ◽  
Ze-Yu Ruan ◽  
Jie-Yu Zheng ◽  
Yan-Cong Chen ◽  
Si-Guo Wu ◽  
...  
Keyword(s):  
Single Molecule ◽  
Structural Engineering ◽  
Magnetic Hysteresis ◽  
Sweep Rate ◽  
Coordination Bond ◽  
Pentagonal Bipyramid ◽  
Single Molecule Magnets ◽  
Crystal Field Theory ◽  
Bond Angles ◽  
Axial Coordination

<p><a></a>Controlling molecular magnetic anisotropy via structural engineering is delicate and fascinating, especially for single-molecule magnets (SMMs). Herein a family of dysprosium single-ion magnets (SIMs) sitting in pentagonal bipyramid geometry have been synthesized with the variable-size terminal ligands and counter anions, through which the subtle coordination geometry of Dy(III) can be finely tuned based on the size effect. The effective energy barrier (Ueff) successfully increases from 439 K to 632 K and the magnetic hysteresis temperature (under a 200 Oe/s sweep rate) raises from 11 K to 24 K. Based on the crystal-field theory, a semi-quantitative magneto-structural correlation deducing experimentally for the first time is revealed that the Ueff is linearly proportional to the structural-related value S2<sup>0</sup> corresponding to the axial coordination bond lengths and the bond angles. Through the evaluation of the remanent magnetization from hysteresis, quantum tunneling of magnetization (QTM) is found to exhibit negative correlation with the structural-related value S<sub>tun</sub> corresponding to the axial coordination bond angles.<br></p>

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.

scholarly journals Magnetic Hysteresis at 10 K in Single Molecule Magnet Self‐Assembled on Gold

2021 ◽  
pp. 2000777
Author(s):  
Chia‐Hsiang Chen ◽  
Lukas Spree ◽  
Emmanouil Koutsouflakis ◽  
Denis S. Krylov ◽  
Fupin Liu ◽  
...  
Keyword(s):  
Single Molecule ◽  
Magnetic Hysteresis ◽  
Single Molecule Magnet ◽  
Self Assembled
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