A. Falepin, S. Cottenier, C.M. Comrie, O. Richard, H. Bender, G. Langouche, A. Vantomme Hyperfine Interactions 151-152 (1-4), 131-1442003A1Published while none of the authors were employed at the CMMDOI http://dx.doi.org/10.1023/B:HYPE.0000020412.84450.6c