Detection of ground states in frustrated molecular rings by in-field local magnetization profiles

Antkowiak, Michał; Kozłowski, P.; Kamieniarz, G.; Timco, Grigore A.; Tuna, Floriana; Winpenny, Richard E. P.

doi:10.1103/physrevb.87.184430

Cited by 48 publications

(56 citation statements)

References 31 publications

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“…These results compare very well with the theoretical values −2.71µ B and +2.72µ B for AFM conguration and +2.78µ B and +2.77µ B for FM conguration, obtained by the LAPW method for the PBE functional in [4] and with the experimental value 2.97µ B [2,26,27].…”

Section: Resultssupporting

confidence: 77%

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DFT Estimation of Exchange Coupling Constant of Cr₈Molecular Ring using the Hybrid Functional B3LYP

2015

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A study of electronic and magnetic properties of an octametallic chromium-based homonuclear molecule Cr8F8(CO2 − C(CH3)3)16 is presented, using density functional theory (DFT) approach and linearized augmented plane wave (LAPW) method with Perdew, Burke and Ernzerhof (PBE) and Becke 3-term correlation (B3LYP) functionals. The exchange coupling parameters between transition metals ions are extracted, taking into account two dierent (ferro-and antiferromagnetic) spin congurations. The value J = 3.1 meV found for the hybrid B3LYP functional improves signicantly the one obtained for the PBE functional and gives an evidence for the superiority of the former in simulation of molecular nanomgnets. Moreover, the hybrid functional yields excellent spin density localisation, an enhancement of the HOMO-LUMO gaps and the value 2.81µB of magnetic moment at the chromium centre in good agreement with experiment.

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Section: Resultssupporting

confidence: 77%

“…In our calculations we do not include spin-orbit coupling, as it was already shown that the dierences in the results are negligible [4,13] and the single-ion anisotropy for the Cr ions is known to be very small [2,26,27]. …”

Section: Dft Approachmentioning

confidence: 99%

DFT Estimation of Exchange Coupling Constant of Cr₈Molecular Ring using the Hybrid Functional B3LYP

2015

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“…In this state the total magnetic moment m = 3µ B . A significant spin polarization of the charge density is found only (410) close to the transition metal atoms, conrming a localized picture of the Cr magnetic moments [10] Coupling constants were also estimated using the standard broken symmetry approach [11]. Fig.…”

Section: Resultsmentioning

confidence: 99%

Mapping of the DFT Spin Configuration Energies of Cr8Cd Molecular Ring onto the Energy Structure of Falicov-Kimball Model

et al. 2015

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A comprehensive study of electronic and magnetic properties of a recently synthesized nonametalic chromiumbased heteronuclear molecule Cr8CdF9(O2C − C(CH3)3)18 is presented, using DFT and FalicovKimball (FK) model approach. The magnetic moments are calculated and the spin charge density map is discussed. The exchange coupling parameters between transition metals ions are extracted, taking into account all the nonequivalent spin congurations. It is demonstrated that the energies of the spin congurations can be reproduced by the FK model with a set of parameters consistent with that for the parent Cr8 molecule. For molecular ring considered, the ground state corresponds to the antiferromagnetic conguration and the ferromagnetic conguration yields the highest energy.

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“…Cr 9 contains nine AF-coupled Cr 3+ ions (s = 3/2). Previously studied Cr 9 molecules have had one significant bond defect, with only one pivalate and one fluoride on one Cr-Cr edge 20,21 , leading to a significantly weaker exchange interaction between those two Cr 3+ ions. The Cr 9 variant studied in this paper, with a formula Cr 9 F 9 { O 2 CC(CH 3 ) 2 } 18 23 has identical bridging on each edge, with one fluoride and two pivalates present on each edge.…”

Section: Introductionmentioning

confidence: 99%

“…Another interesting molecule is the {V O} 7 19 ring, which has been characterized only by low-temperature DC magnetization measurements. Recently, the first examples of Cr 9 rings have been synthesized and studied [20][21][22] , but none of them displays the characteristics of a degenerate-frustrated ring. Indeed, they all have at least one significant bond defect, leading to a sizeable removal of the degeneracy in the S = 1/2 ground state or even to a ground state with S > 1/2.…”

Section: Introductionmentioning

confidence: 99%

Relaxation dynamics in the frustratedCr9antiferromagnetic ring probed by NMR

et al. 2016

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We investigate the magnetic properties and the phonon-induced relaxation dynamics of the the first regular Cr9 antiferromagnetic (AF) ring, which represents a prototype frustrated AF ring. Geometrical frustration in Cr9 yields an energy spectrum with twofold degenerate low-lying levels and a low-spin ground state. The electronic relaxation dynamics is probed by 1 H-NMR through the temperature dependence of the spin-lattice relaxation rate 1/T1. We develop a microscopic model that reproduces 1/T1(T ) curves, taking also into account the wipeout effect. By interpreting these measurements we determine the spin-phonon coupling strength and we investigate the decay of the cluster magnetization due to the spin-phonon interaction. We find that at very low temperatures the relaxation is characterized by a single dominating Arrhenius-type relaxation process, whereas several relevant processes emerge at higher temperatures. In addition, we calculate the temperature and magnetic field dependence of level lifetimes.

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Detection of ground states in frustrated molecular rings by in-field local magnetization profiles

Cited by 48 publications

References 31 publications

DFT Estimation of Exchange Coupling Constant of Cr₈Molecular Ring using the Hybrid Functional B3LYP

DFT Estimation of Exchange Coupling Constant of Cr₈Molecular Ring using the Hybrid Functional B3LYP

Mapping of the DFT Spin Configuration Energies of Cr8Cd Molecular Ring onto the Energy Structure of Falicov-Kimball Model

Relaxation dynamics in the frustratedCr9antiferromagnetic ring probed by NMR

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Detection of ground states in frustrated molecular rings by in-field local magnetization profiles

Cited by 48 publications

References 31 publications

DFT Estimation of Exchange Coupling Constant of Cr8Molecular Ring using the Hybrid Functional B3LYP

DFT Estimation of Exchange Coupling Constant of Cr8Molecular Ring using the Hybrid Functional B3LYP

Mapping of the DFT Spin Configuration Energies of Cr8Cd Molecular Ring onto the Energy Structure of Falicov-Kimball Model

Relaxation dynamics in the frustratedCr9antiferromagnetic ring probed by NMR

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DFT Estimation of Exchange Coupling Constant of Cr₈Molecular Ring using the Hybrid Functional B3LYP

DFT Estimation of Exchange Coupling Constant of Cr₈Molecular Ring using the Hybrid Functional B3LYP