A method to predict both the relaxation time of quantum tunneling of magnetization and the effective barrier of magnetic reversal for a Kramers single-ion magnet

Abstract

A method to predict the relaxation time of quantum tunneling of magnetization and the magnetic reversal barrier with efficiency and reliability.

Slow magnetic relaxation in distorted tetrahedral Dy(iii) aryloxide complexes

“…The subsequent ES 1 (Excited State 1) and ES 2 are at 200 and 366 cm −1 for 1 , 178 and 274 cm −1 for 2 and 139 and 172 cm −1 for 3 , with higher mixing of the m J levels occurring above this energy. The QTM rates were calculated at each m J level within the thermally-assisted QTM (TA-QTM) frameworks 25 to show significant QTM probabilities on all m J levels; the low-lying state QTM rates are 7.1 s −1 (GS) and 2.3 × 10 3 s −1 (ES 1 ) for 1 , 8.8 × 10 2 s −1 (GS) and 6.1 × 10 6 s −1 (ES 1 ) for 2 and 6.4 × 10 3 s −1 (GS) and 4.5 × 10 8 s −1 (ES 1 ) for 3 (Table S8, ESI † ). The calculated QTM rates at GS and ES1 are lowest for 1 and highest for 3 , indicating an increase in QTM from 1 < 2 < 3 .…”

Homochiral Dysprosium Phosphonate Nanowires: Morphology Control and Magnetic Dynamics

“…The most important KD contribution to U eff is KD 3 for S ‐1 , and the most two important KDs contributions to U eff are KD 3 and KD 4 for S ‐3 . According to the equations S1–S3, [41–43] we calculated the U eff of individual Dy III fragments for S ‐1 and S ‐3 . The calculated saturation U eff for individual Dy III fragments of S ‐1 and S ‐3 are 225.2 and 375.5 cm −1 , respectively, which are actually not available in experimental observation since a least temperature of ca.…”

“…Recently, Aravena et al [41–43] . proposed a new method for the prediction of effective demagnetization barriers ( U eff ) considering all state energies and their contributions to the tunneling rate.…”

Molecular magnetic properties of a dysprosium(III) complex coordinated to a nonadentate bispidine ligand

“…[2][3][4][5] The key feature of SMMs is a high blocking temperature T B (the temperature below which an SMM retains magnetization for a certain time), and this depends on quantum tunneling of magnetization in the low temperature regime and thermal relaxation described by the anisotropy barrier U eff . [6][7][8][9][10] The historic Mn 12 SMM has a blocking temperature below 4 K (effective barrier of about 42 cm À 1 ) and therefore primarily is of academic interest. [2] Decisive for blocking of the magnetization is the splitting of the ground state multiplet and this primarily depends on the ligand field and the spin-orbit coupling, and for a suitable SMM the magnetic anisotropy should be axial and the ground states should mainly consist of the m s = S and -S states.…”