Local magnetic fields in antiferromagnetic Bi2CuO4:: as seen from 63,65Cu and 209Bi nuclear resonance

A complex spin-echo spectrum of Cu-63,Cu-65 and Bi-209 has been observed in antiferromagnetic Bi2CuO4 at 4.2 K. The spectrum consists of Cu-63,Cu-65 AFNR and Bi-209 NQR, The Cu AFNR is characterized by the internal field H-int = 99 kOe at Cu nuclei and by the (63)nu(Q) = 10 MHz. It is argued that the low-limit of the internal field at the Bi-209 nuclei is 4.3 kOe. The occurrence of H-hf at Bi-209 nuclei shows that Bi3+ anions take part in the superexchange interaction between Cu atoms along the Cu-O-Bi-O-Cu bonds. (C) 2000 Published by Elsevier Science B.V. All rights reserved.