Structural influences on the exchange coupling and zero-field splitting in the single-molecule magnet [MnIII6MnIII]3+

2012 ◽  
Vol 41 (41) ◽  
pp. 12942 ◽  
Author(s):  
Veronika Hoeke ◽  
Maik Heidemeier ◽  
Erich Krickemeyer ◽  
Anja Stammler ◽  
Hartmut Bögge ◽  
...  
Keyword(s):  
Single Molecule ◽  
Exchange Coupling ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Single Molecule Magnet

scholarly journals First-Principles Investigations of Magnetic Anisotropy and Spin-Crossover Behavior of Fe(III)-TBP Complexes

2020 ◽  
Author(s):  
Rishu Khurana ◽  
Sameer Gupta ◽  
Md. Ehesan Ali
Keyword(s):  
Single Molecule ◽  
First Principles ◽  
Density Functional ◽  
Spin Crossover ◽  
Zero Field ◽  
Spin States ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
B3lyp Functional ◽  
D Values

<div>With the ongoing efforts to obtain mononuclear 3d-transition metal complexes that manifest slow relaxation of magnetization and hence, can behave as single molecule magnets (SMMs), we have modelled 14 novel Fe(III) complexes out of which nine behave as potential SMMs. These complexes possess large zero-field splitting (ZFS)</div><div>parameter D in the range of -40 to -60 cm<sup>-1</sup>. The first-principles investigation of the ground-spin state applying density functional theory (DFT) and wave-function based</div><div>multi-configurations methods e.g. SA-CASSCF/NEVPT2 are found to be quite consistent except for few delicate cases with near degenerate spin-states. In such cases, the</div><div>hybrid B3LYP functional is found to be biased towards high-spin (HS) state. Altering the percentage of exact exchange admixed in B3LYP functional leads to intermediate spin</div><div>(IS) ground state consistent with the multireference calculations. The origin of large zero field splitting (ZFS) in the Fe(III)-based trigonal bipyramidal (TBP) complexes</div><div>is investigated and the D-values are further tuned by varying the axial ligands with group XV elements (N, P and As) and equatorial halide ligands from F, Cl, Br and I. Furthermore, a number of complexes are identified with very small Gibbs free energy values indicating the possible spin-crossover phenomenon between the bi-stable spin-states.</div>

scholarly journals Is [ReCl4(CN)2]2− a good Building Block for Single Molecule Magnets? A Theoretical Investigation.

2022 ◽  
Author(s):  
Christoph van Wüllen ◽  
Eva M. V. Kessler
Keyword(s):  
Single Molecule ◽  
Building Blocks ◽  
Ligand Field ◽  
Zero Field ◽  
Spin Orbit ◽  
Computational Results ◽  
Zero Field Splitting ◽  
Single Molecule Magnets ◽  
Field Splitting ◽  
Orbit Perturbation

Building blocks containing $5d$ spin centres are promising for constructing single molecule magnets due to their large spin-orbit interaction, but experimental and computational results obtained so far indicate that this might not be the case for Re$^\textrm{IV}$ centres in an octahedral environment. Density functional results obtained in this work for [ReCl$_4$(CN)$_2$]$^{2-}$ and trinuclear complexes formed by attaching Mn$^\textrm{II}$ centres to the cyano ligands indicate that zero field splitting in such complexes exhibits large rhombicity (which leads to fast relaxation of the magnetisation) even if there are only small distortions from an ideal geometry with a four-fold symmetry axis. This is already apparent if second-order spin-orbit perturbation theory is applied but even more pronounced if higher-order spin-orbit effects are included as well, as demonstrated by wavefunction based calculations. Computational results are cast into a ligand field model and these simulations show that especially a distortion which is not along the $C_4/C_2$ axeshas a large effect on the rhombicity. Quantum simulations on these complexes are difficult because the zero field splitting strongly depends on the energetic position of the low-lying doublets from the $t_{2g}^3$ configuration.

Structure and Magnetism in Fe–Gd Based Dinuclear and Chain Systems. The Interplay of Weak Exchange Coupling and Zero Field Splitting Effects

2011 ◽  
Vol 51 (1) ◽  
pp. 40-50 ◽  
Author(s):  
Marilena Ferbinteanu ◽  
Fanica Cimpoesu ◽  
Mihai A. Gîrţu ◽  
Cristian Enachescu ◽  
Stefania Tanase
Keyword(s):  
Exchange Coupling ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Weak Exchange

scholarly journals First-Principles Investigations of Magnetic Anisotropy and Spin-Crossover Behavior of Fe(III)-TBP Complexes

2020 ◽  
Author(s):  
Rishu Khurana ◽  
Sameer Gupta ◽  
Md. Ehesan Ali
Keyword(s):  
Single Molecule ◽  
First Principles ◽  
Density Functional ◽  
Spin Crossover ◽  
Zero Field ◽  
Spin States ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
B3lyp Functional ◽  
D Values

<div>With the ongoing efforts to obtain mononuclear 3d-transition metal complexes that manifest slow relaxation of magnetization and hence, can behave as single molecule magnets (SMMs), we have modelled 14 novel Fe(III) complexes out of which nine behave as potential SMMs. These complexes possess large zero-field splitting (ZFS)</div><div>parameter D in the range of -40 to -60 cm<sup>-1</sup>. The first-principles investigation of the ground-spin state applying density functional theory (DFT) and wave-function based</div><div>multi-configurations methods e.g. SA-CASSCF/NEVPT2 are found to be quite consistent except for few delicate cases with near degenerate spin-states. In such cases, the</div><div>hybrid B3LYP functional is found to be biased towards high-spin (HS) state. Altering the percentage of exact exchange admixed in B3LYP functional leads to intermediate spin</div><div>(IS) ground state consistent with the multireference calculations. The origin of large zero field splitting (ZFS) in the Fe(III)-based trigonal bipyramidal (TBP) complexes</div><div>is investigated and the D-values are further tuned by varying the axial ligands with group XV elements (N, P and As) and equatorial halide ligands from F, Cl, Br and I. Furthermore, a number of complexes are identified with very small Gibbs free energy values indicating the possible spin-crossover phenomenon between the bi-stable spin-states.</div>

Correlating the axial Zero Field Splitting with the slow magnetic relaxation in GdIII SIMs

2021 ◽  
Author(s):  
Júlia Mayans ◽  
Albert Escuer
Keyword(s):  
Magnetic Relaxation ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Slow Magnetic Relaxation

A possible relation between the value of the axial Zero Field Splitting and the occurrence of field-induced slow magnetic relaxation has been established for a new gadolinium(iii) compound.

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