[1] FORSCHUNGSZENTRUM JULICH GMBH,INST FESTKORPERFORSCH,W-5170 JULICH,GERMANY
[2] JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218
[3] TECHNION ISRAEL INST TECHNOL,INST SOLID STATE,IL-32000 HAIFA,ISRAEL
[4] MAX PLANCK INST FESTKORPERFORSCH,HOCHFELD MAGNETLAB,F-38042 GRENOBLE,FRANCE
[5] HAIFA UNIV,ORANIM,DEPT MATH & PHYS,IL-36910 TIVON,ISRAEL