TY - JOUR
T1 - Single-Molecule Magnets DyM2N@C80and Dy2MN@C80(M=Sc, Lu): The Impact of Diamagnetic Metals on Dy3++Magnetic Anisotropy, Dy···Dy Coupling, and Mixing of Molecular and Lattice Vibrations
AU - Spree, Lukas
AU - Schlesier, Christin
AU - Kostanyan, Aram
AU - Westerström, Rasmus
AU - Greber, Thomas
AU - Büchner, Bernd
AU - Avdoshenko, S. M.
AU - Popov, A
PY - 2020
Y1 - 2020
N2 - The substitution of scandium in fullerene single‐molecule magnets (SMMs) DySc2N@C80 and Dy2ScN@C80 by lutetium has been studied to explore the influence of the diamagnetic metal on the SMM performance of dysprosium nitride clusterfullerenes. The use of lutetium led to an improved SMM performance of DyLu2N@C80, which shows a higher blocking temperature of magnetization (TB=9.5 K), longer relaxation times, and broader hysteresis than DySc2N@C80 (TB=6.9 K). At the same time, Dy2LuN@C80 was found to have a similar blocking temperature of magnetization to Dy2ScN@C80 (TB=8 K), but substantially different interactions between the magnetic moments of the dysprosium ions in the Dy2MN clusters. Surprisingly, although the intramolecular dipolar interactions in Dy2LuN@C80 and Dy2ScN@C80 are of similar strength, the exchange interactions in Dy2LuN@C80 are close to zero. Analysis of the low‐frequency molecular and lattice vibrations showed strong mixing of the lattice modes and endohedral cluster librations in k‐space. This mixing simplifies the spin–lattice relaxation by conserving the momentum during the spin flip and helping to distribute the moment and energy further into the lattice.
AB - The substitution of scandium in fullerene single‐molecule magnets (SMMs) DySc2N@C80 and Dy2ScN@C80 by lutetium has been studied to explore the influence of the diamagnetic metal on the SMM performance of dysprosium nitride clusterfullerenes. The use of lutetium led to an improved SMM performance of DyLu2N@C80, which shows a higher blocking temperature of magnetization (TB=9.5 K), longer relaxation times, and broader hysteresis than DySc2N@C80 (TB=6.9 K). At the same time, Dy2LuN@C80 was found to have a similar blocking temperature of magnetization to Dy2ScN@C80 (TB=8 K), but substantially different interactions between the magnetic moments of the dysprosium ions in the Dy2MN clusters. Surprisingly, although the intramolecular dipolar interactions in Dy2LuN@C80 and Dy2ScN@C80 are of similar strength, the exchange interactions in Dy2LuN@C80 are close to zero. Analysis of the low‐frequency molecular and lattice vibrations showed strong mixing of the lattice modes and endohedral cluster librations in k‐space. This mixing simplifies the spin–lattice relaxation by conserving the momentum during the spin flip and helping to distribute the moment and energy further into the lattice.
U2 - 10.1002/chem.201904879
DO - 10.1002/chem.201904879
M3 - Article
C2 - 31774196
SN - 1521-3765
VL - 26
SP - 2436
EP - 2449
JO - Chemistry: A European Journal
JF - Chemistry: A European Journal
IS - 11
ER -