MOSSBAUER EXPERIMENTS WITH COULOMB-EXCITED 73GE AFTER COULOMB RECOIL IMPLANTATION

The nuclear resonance absorption of the 67.03 keV de‐excitation radiation of 73Ge*, Coulomb‐excited by 20 to 30 MeV 16O ions, is studied. The recoiling 73Ge° nuclei are implanted into a chromium substrate. The electronic configurations Ge (4s1 p3) in Ge (cryst.), Ge (15% (4s2 p0), 85% (4s2 p2)) in Ge (II)Se, Ge (62% (4s0 p0), 38% (4s1 p3)) in GeO2 (hex.) and GeO2 (tetr.), and the ratio δ R/R=1.12 × 10−3 of the nuclear charge radius are compatible with the measured isomeric shifts. Line broadenings and recoil‐free fractions f of the implantation target and the absorbers are determined. At 78 °K f GeO 2(tetr.) is greater than f GeO 2(hex.) by a factor of six. Copyright © 1968 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim