Electron paramagnetic resonance study of ErSc2NC80

Abstract

We present an electron paramagnetic resonance (EPR) study of ErSc2N@C80 fullerene in which there are two Er 3+ sites corresponding to two different configurations of the ErSc2N cluster inside the C80 cage. For each configuration, the EPR spectrum is characterized by a strong anisotropy of the g-factors (gx,y = 2.9, gz = 13.0 and gx,y = 5.3, gz = 10.9). Illumination within the cage absorption range (λ < 600 nm) induces a rearrangement of the ErSc2N cluster inside the cage. We follow the temporal dependence of this rearrangement phenomenologically under various conditions.

Endohedral Fullerenes

“…The energies of the lowest excited states determined for both configurations (ca. 30 cm −1 ) 534,535 corresponded well to the energy difference between the lowest and second lowest crystal-field levels of the Er 3+ ion in its ground state ( 4 I 15/2 ) determined by photoluminescence spectroscopy. 595 In 2012 Jańossy et al reported high-frequency (210 and 315 GHz) ESR spectroscopic study of Gd 3 N@C 80 at different temperatures.…”

“…Lanthanide-Based M 3 N@C 80 . Although many NCFs are intrinsically paramagnetic due to the unfilled f-shell of rare-earth metals in the M 3 N cluster, ESR spectroscopic characterization has been accomplished so far only for ErSc 2 N@C 80 -I h (7) 534,535 and Gd 3 N@C 80 -I h (7). 594 The X-band ESR spectrum of ErSc 2 N@ C 80 measured at 5 K in frozen toluene solution exhibited a complex pattern which was interpreted taking into account two different Er 3+ sites, presumably corresponding to different orientations of the ErSc 2 N cluster inside the cage.…”

“…One of the configurations exhibited rather narrow spectral lines which allowed the determination of the tensor components for hyperfine and nuclear-quadrupole interactions. 535 Studying the temperature dependence of the line widths, the authors have shown that the spin−lattice relaxation follows Orbach mechanism via excited state. The energies of the lowest excited states determined for both configurations (ca.…”