Volume 82, Number 3, May 2008
Article Number 37002
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 16 April 2008
EPL, 82 (2008) 37002
DOI: 10.1209/0295-5075/82/37002

Magnetic resonance of the new neutral Al cluster radical [Al7R6]

S. Domingo Köhler1, B. Pilawa1, D. Saez de Jauregui1, G. Fischer1, R. Grubba2, R. Köppe2, A. Schnepf2, H. Schnöckel2 and E. Dormann1

1  Physikalisches Institut, Universität Karlsruhe (TH) - D-76128 Karlsruhe, Germany, EU
2  Institut für Anorganische Chemie, Universität Karlsruhe (TH) - D-76128 Karlsruhe, Germany, EU

received 19 December 2007; accepted in final form 5 March 2008; published May 2008
published online 16 April 2008

Static magnetometry and continuous-wave and pulsed-electron spin resonance (ESR) is used for the characterization of the neutral radical cluster [Al(Al3R3)2]$^{\bullet}$ (R = N(SiMe2Ph)2). For temperatures below 25 K, we prove its monoradical character, a g-factor of 1.997$\hbox{--}$1.991, and a three time larger hyperfine interaction with the central than with the six outer 27Al nuclei of the [Al7R6]$^{\bullet}$ cluster radical. Temperature dependence of the low-temperature spin-lattice relaxation is analysed. At temperatures above 30 K, the effective moment per cluster increases, and the hyperfine interaction with the seven 27Al nuclei is equalized.

76.30.-v - Electron paramagnetic resonance and relaxation.
76.30.Rn - Free radicals.

© EPLA 2008