Naslov
C60 molecular configurations leading to ferromagnetic exchange interactions in TDAE*C60

Autori
Narymbetov, B. ; Omerzu, A. ; Kabanov, V. ; Tokumoto, M. ; Kobayashi, H. ; Mihailovic, D.

Izvornik
Physics of the Solid State (1063-7834) 44 (2002), 3; 437-440

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
TDAE-C-60

Sažetak
The charge-transfer salt tetrabis(dimethylamino)ethylene-fullerene (C- 60), or TDAE*C-60, is a rare exception among pure organic crystalline systems, because it shows a transition to a ferromagnetic (FM) state with fully saturated s = 1/2 molecular spins at a respectable T-c = 16 K. In spite of extensive experimental and theoretical work over the past ten years, the origin of the ferromagnetism in TDAE*C-60 has remained a mystery. To resolve this problem, we performed a comparative structural study of two different magnetic forms of TDAE*C-60 crystals, one of which is magnetic and the other is nonmagnetic at low temperatures, and fully correlated their structural properties (particularly, the intermolecular orientations) with their magnetic properties. We identified the relative orientation of C-60 molecules along the c axis as the primary variable that controls the ferromagnetic order parameter and showed that both FM and low-temperature spin-glass-like ordering are possible in this material, depending on the orientational state of the C- 60 molecules. Thus, we resolved the apparent contradictions intrinsic to different macroscopic measurements and opened a path to a microscopic understanding of p-electron FM exchange interactions.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Interdisciplinarne prirodne znanosti

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