[1] CNRS, Fac Luminy, F-13288 Marseille 9, France
[2] Johannes Kepler Univ Linz, Inst Expt Phys, A-4040 Linz, Austria
[3] Univ H Poincare, LCSM, F-54506 Vandoeuvre Les Nancy, France
[4] Inst Laue Langevin, F-38042 Grenoble 9, France
[5] Univ Washington, Dept Phys, Seattle, WA 98195 USA
[6] Makassar State Univ, Dept Phys, Makassar, Indonesia