BI-209 NQR AND MAGNETIC-PROPERTIES OF BISMUTH OXIDE-BASED COMPOUNDS

The NQR line shapes of Bi-209 in the alpha-Bi2O3-based mixed oxides Bi 2O3. 2M(2)O(3) (M = Al, Ga). Bi2O3. 3GeO(2), and 2B(2)O(3). 3GeO(2) ar e recorded in zero and weak magnetic fields (H-ext < 500 Oe) and compa red with the results of computer simulation. Splittings and line shape asymmetry, exhibited by the resonances, suggest that internal magneti c fields, similar to those earlier reported for alpha-Bi2O3 and Bi3O4B r, may exist in these compounds. In the spectra of single crystal Bi4G e3O12, the line multiplicity in external magnetic fields is higher tha n simulated, which might results from domains in the crystal. In exter nal magnetic fields a notable increase in the line intensity was obser ved, the effect depending on the mutual orientation of the EFG axes an d the fields perturbing the nuclear spin system.