Attempting to understand (and control) the relationship between structure and magnetism in an extended family of Mn6 single-molecule magnets

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.

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Polarized Neutron Diffraction: An Excellent Tool to Evidence the Magnetic Anisotropy—Structural Relationships in Molecules

Magnetochemistry ◽

10.3390/magnetochemistry7120158 ◽

2021 ◽

Vol 7 (12) ◽

pp. 158

Author(s):

Dominique Luneau ◽

Béatrice Gillon

Keyword(s):

Neutron Diffraction ◽

Magnetic Anisotropy ◽

Single Molecule ◽

Coordination Compounds ◽

Single Molecule Magnets ◽

Structural Relationships ◽

Polarized Neutron ◽

The Individual ◽

The Relationship ◽

Excellent Tool

This publication reviews recent advances in polarized neutron diffraction (PND) studies of magnetic anisotropy in coordination compounds comprising d or f elements and having different nuclearities. All these studies illustrate the extent to which PND can provide precise and direct information on the relationship between molecular structure and the shape and axes of magnetic anisotropy of the individual metal sites. It makes this experimental technique (PND) an excellent tool to help in the design of molecular-based magnets and especially single-molecule magnets for which strong uniaxial magnetic anisotropy is required.

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Insights in Magnetodynamics from a Simple Two-Level Model

10.26434/chemrxiv.12246194.v1 ◽

2020 ◽

Author(s):

Stanislav Avdoshenko ◽

Rajyavardhan Ray

Keyword(s):

Density Matrix ◽

Single Molecule ◽

Quantum Dynamics ◽

Single Molecule Magnets ◽

Recent Contribution ◽

Level Model ◽

Theory Of Optimal Control ◽

Reduced Density ◽

And Control ◽

Manipulation And Control

With single-molecule magnets research on the rise as a result of recent advantages in the field, like remarkable high blocking temperatures up to 60 Kelvin [Nature, 548, 439, 2017], gigantic coercivity up to 80 Tesla [Nat Commun., 10, 571, 2019], magnetization stability in the thin films, further applications are seriously in the scope. The possible venue here is to develop a theory of magnetic moment manipulation and control at the microscopic level. Theory of optimal control in quantum dynamics in complex systems is well-developed. For example, the uses of density matrix techniques have been well summarized already in the early ‘60s by Fano, Haar, and many others. Thus, in many respects, the task is to reframe that research into the language of the problem at hand, and into familiar terms for the community. Recently, it was already proven the Redfield reduced density matrix techniques are applicable for slow-relaxing single-molecule magnets [Nat Commun., 8, 14620, 2017]. In our recent contribution[PCCP,20, 11656, 2018], we have outlined the use of Lindblad dynamics in combination with a few axioms in the rationalization of the relaxation behavior of single-molecule magnets. In this report we put this approach in the context of the magentodynamics theory, showing the close connection to the Landau-Lifshitz-Gilbert model and presenting further elaboration for the proposed method.

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Insights in Magnetodynamics from a Simple Two-Level Model

10.26434/chemrxiv.12246194 ◽

2020 ◽

Author(s):

Stanislav Avdoshenko ◽

Rajyavardhan Ray

Keyword(s):

Density Matrix ◽

Single Molecule ◽

Quantum Dynamics ◽

Single Molecule Magnets ◽

Recent Contribution ◽

Level Model ◽

Theory Of Optimal Control ◽

Reduced Density ◽

And Control ◽

Manipulation And Control

With single-molecule magnets research on the rise as a result of recent advantages in the field, like remarkable high blocking temperatures up to 60 Kelvin [Nature, 548, 439, 2017], gigantic coercivity up to 80 Tesla [Nat Commun., 10, 571, 2019], magnetization stability in the thin films, further applications are seriously in the scope. The possible venue here is to develop a theory of magnetic moment manipulation and control at the microscopic level. Theory of optimal control in quantum dynamics in complex systems is well-developed. For example, the uses of density matrix techniques have been well summarized already in the early ‘60s by Fano, Haar, and many others. Thus, in many respects, the task is to reframe that research into the language of the problem at hand, and into familiar terms for the community. Recently, it was already proven the Redfield reduced density matrix techniques are applicable for slow-relaxing single-molecule magnets [Nat Commun., 8, 14620, 2017]. In our recent contribution[PCCP,20, 11656, 2018], we have outlined the use of Lindblad dynamics in combination with a few axioms in the rationalization of the relaxation behavior of single-molecule magnets. In this report we put this approach in the context of the magentodynamics theory, showing the close connection to the Landau-Lifshitz-Gilbert model and presenting further elaboration for the proposed method.

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From Container to Claustrum: Projective Identification in Couples

Couple and Family Psychoanalysis ◽

10.33212/cfp.v4n2.2014.136 ◽

2014 ◽

Vol 4 (2) ◽

Cited By ~ 1

Author(s):

Tamara Feldman

Keyword(s):

Psychological Health ◽

Projective Identification ◽

The Self ◽

The Other ◽

Intimate Partners ◽

And Control ◽

The Relationship ◽

As If

This paper is a contribution to the growing literature on the role of projective identification in understanding couples' dynamics. Projective identification as a defence is well suited to couples, as intimate partners provide an ideal location to deposit unwanted parts of the self. This paper illustrates how projective identification functions differently depending on the psychological health of the couple. It elucidates how healthier couples use projective identification more as a form of communication, whereas disturbed couples are inclined to employ it to invade and control the other, as captured by Meltzer's concept of "intrusive identification". These different uses of projective identification affect couples' capacities to provide what Bion called "containment". In disturbed couples, partners serve as what Meltzer termed "claustrums" whereby projections are not contained, but imprisoned or entombed in the other. Applying the concept of claustrum helps illuminate common feelings these couples express, such as feeling suffocated, stifled, trapped, held hostage, or feeling as if the relationship is killing them. Finally, this paper presents treatment challenges in working with more disturbed couples.

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

10.26434/chemrxiv.11475291 ◽

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

<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 S20 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 Stun corresponding to the axial coordination bond angles.

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Correlating Blocking Temperatures in Single Molecule Magnets with Raman Relaxation

10.26434/chemrxiv.7067669 ◽

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 (SMM) with an energy barrier of 1110 K for thermal relaxation of magnetization. The sample shows no retention of magnetization even at 2 K and this led us to find a good correlation between the blocking temperature and the Raman relaxation regime for SMMs. The key parameter is the relaxation time (𝜏switch) at the point where the Raman relaxation mechanism becomes more important than Orbach.

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A Combined Spin-Flip and IP/EA Approach for Handling Spin and Spatial Degeneracies: Application to Double Exchange Systems

10.26434/chemrxiv.7445939.v1 ◽

2018 ◽

Author(s):

Shannon Houck ◽

Nicholas Mayhall

Keyword(s):

Single Molecule ◽

Double Exchange ◽

Computational Effort ◽

Strongly Correlated ◽

Single Molecule Magnets ◽

New Approach ◽

Spin Flip ◽

Model Hamiltonian ◽

Simultaneous Existence ◽

Exchange Parameters

<div>Many multiconfigurational systems, such as single-molecule magnets, are difficult to study using traditional computational methods due to the simultaneous existence of both spin and spatial degeneracies. In this work, a new approach termed n-spin-flip Ionization Potential/Electron Affinity (nSF-IP or nSF-EA) is introduced which combines the spin-flip method of Anna Krylov with particle-number changing IP/EA methods. We demonstrate the efficacy of the approach by applying it to the strongly-correlated N2+ as well as several double exchange systems. We also demonstrate that when these systems are well-described by a double exchange model Hamiltonian, only 1SF-IP/EA is required to extract the double exchange parameters and accurately predict energies for the low-spin states. This significantly reduces the computational effort for studying such systems. The effects of including additional excitations (using a RAS-nSF-IP/EA scheme) are also examined, with particular emphasis on hole and particle excitations.</div>

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A Combined Spin-Flip and IP/EA Approach for Handling Spin and Spatial Degeneracies: Application to Double Exchange Systems

10.26434/chemrxiv.7445939 ◽

2018 ◽

Author(s):

Shannon Houck ◽

Nicholas Mayhall

Keyword(s):

Single Molecule ◽

Double Exchange ◽

Computational Effort ◽

Strongly Correlated ◽

Single Molecule Magnets ◽

New Approach ◽

Spin Flip ◽

Model Hamiltonian ◽

Simultaneous Existence ◽

Exchange Parameters

<div>Many multiconfigurational systems, such as single-molecule magnets, are difficult to study using traditional computational methods due to the simultaneous existence of both spin and spatial degeneracies. In this work, a new approach termed n-spin-flip Ionization Potential/Electron Affinity (nSF-IP or nSF-EA) is introduced which combines the spin-flip method of Anna Krylov with particle-number changing IP/EA methods. We demonstrate the efficacy of the approach by applying it to the strongly-correlated N2+ as well as several double exchange systems. We also demonstrate that when these systems are well-described by a double exchange model Hamiltonian, only 1SF-IP/EA is required to extract the double exchange parameters and accurately predict energies for the low-spin states. This significantly reduces the computational effort for studying such systems. The effects of including additional excitations (using a RAS-nSF-IP/EA scheme) are also examined, with particular emphasis on hole and particle excitations.</div>

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Content Analysis (Analisis Isi) terhadap Peraturan Daerah Bernuansa Syariat Islam di Kabupaten Banyumas

Jurnal Suara Hukum ◽

10.26740/jsh.v1n2.p121-141 ◽

2019 ◽

Vol 1 (2) ◽

pp. 121

Author(s):

Dody Nur Andriyan

Keyword(s):

Disease Management ◽

Public Interest ◽

Islamic Law ◽

Alcoholic Beverages ◽

Public Issues ◽

Criminal Sanctions ◽

Qualitative Descriptive ◽

Administrative Sanctions ◽

And Control ◽

The Relationship

Regional Regulation (Perda) which regulates public issues such as prostitution, alcoholic beverages, gambling, and the relationship between men and women turns out to be identified as a Regional Regulation with nuances of Islamic law. in Banyumas Regency there is a Regional Regulation which if used by the identification of Arfiansyah above, it can be referred to as a Regional Regulation with nuances of Islamic law. The regulation is: Banyumas District Regulation Number 15 of 2014 concerning Control, Supervision and Control of Circulation of Alcoholic Beverages and Regional Regulations of Banyumas Regency Number 16 of 2015 concerning Community Disease Management. This research has two formulations of the first problem related to the results of the content of the analysis on the Perda that are nuanced by Islamic law in Banyumas Regency. Both of the results of the analysis content on the Regional Regulations that are nuanced by Islamic law in Banyumas Regency are not contrary to Law-Invitation Number 12 of 2011? This research is a qualitative-descriptive study. The research method used is normative juridical. The main source of data is the Banyumas District Regulation Number 15 of 2014 concerning Control, Supervision and Control of Circulation of Alcoholic Beverages and Regional Regulations of Banyumas Regency Number 16 of 2015 concerning Community Disease Management. Interviews were also conducted with resource persons. Furthermore, the results of the analysis were carried out. Regional Regulation No. 15 of 2014 is actually a Regional Regulation that has a broad purpose of public interest, for the nation and state. So that the claim that Perda No 15 of 2014 as a Regional Regulation with nuances of Islamic law is not true. Regional Regulation No. 16 of 2015 is actually a Regional Regulation that has a broad purpose of public interest, for the nation and state. So that the claim that Perda No 16 of 2015 as a Regional Regulation with nuances of Islamic law is not true. Both of these Perda (Perda No 15 of 2014 and Perda No. 16 of 2015) are not in conflict with Law No. 12 of 2011 concerning the Establishment of Legislation. Both in terms of content, principles, goals, arrangements, administrative sanctions and criminal sanctions. Formally and procedurally the two Perda are in accordance with Law Number 12 of 2011

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