The sharp resonance of the Mossbauer effect in Ni-63 was observed for
the first time. The short-lived Co-63 sources (T1/2 = 27 s) were produ
ced via the reaction 64Ni(t, alpha) Co-63. The 64Ni targets and the ra
dioactive absorber (T1/2 = 100 yr) were cooled down to 15 and 4.2 K re
spectively.