Solvent responses and substituent effects upon magnetic properties of mononuclear Dy^III compounds

Abstract

Solvent responsive magnets compose a class of molecule-based materials where latticed solvents driven structural transformation leads to the switching of magnetic properties. Herein, we present a special type of magnet...

The coexistence of longτQTMand highUeffas a concise criterion for a good single-molecule magnet: a theoretical case study of square antiprism dysprosium single-ion magnets

“…Based on ab initio calculations, theoretical methods for the prediction of both τ QTM and U eff have been proposed and applied recently. 6,7,9,30–32,35,67,68,85,86 The reliability of this type of method is reasonable. 6,7,67 One advantage of these methods is that they do not need to calculate either the spin–phonon coupling constant or phonon spectrum.…”

“…7 Although having limited precision, eqn (4d) has been shown to be reliable in previous works. 7,[30][31][32]35,85,86,90 For one Dy-SIM, the computational cost to use eqn (4d) is only one ab initio calculation and thus the efficiency is also satisfactory. The values of g X-Z can be accurately obtained from ab initio calculations 44,46,47,49 and B ave can be empirically estimated.…”

“…Besides that, 50 mT is also selected for B ave here since one recent study has verified its capability in eightcoordinated Dy-SIMs. 32 When both ground and excited KDs are involved, the effect of their thermal populations should be accounted for. Therefore, as shown in eqn (5a), the QTM rate for a given KD i , i.e., t QTM,i À1 (T), is approximated to be proportional to the product of its Boltzmann population and its effective rate t À1,eff QTM,i (eqn (5b)).…”

“…The selection of the whole group of sextets has been shown to be enough for the reliable description of Dy-SIMs. [30][31][32][33]35,60,62,85,86,90 The scalar relativistic effect is accounted for via second-order DKH transformation, i.e., DKH2 Hamiltonian. The second step was performed via the RASSI-SO module 92 with the SOC integrals from the AMFI method.…”

“…[18][19][20]24,25 Mononuclear SMMs are also termed single ion magnets (SIM) and the most attractive SIMs come from the systems based on Kramers lanthanide (Ln) ions, especially Dy 3+ . 5,[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] The blocking temperature (T B ) and effective barrier of magnetic reversal 34 (U eff ) are the two most popular parameters taken as the figure of merit of a SMM. 6 The current records of the highest T B and U eff are indeed held by Dy-SIMs.…”