TIME-DIFFERENTIAL PERTURBED-ANGULAR-CORRELATION STUDIES ON IN-117 ANDCD-111 IN LI0.995CD0.005NBO3

The nuclear-electric-quadrupole interactions at In-117 and Cd-111 nucl ei arising from Cd-117 and Cd-111m, respectively, chemically introduce d in Li0.995Cd0.005NbO3 polycrystals were studied using the time-diffe rential perturbed angular correlation of gamma rays. The \V-zz(lattice )\ values derived for In-117 and Cd-111 coincided with each other, i.e ., 3.4(1) x 10(20) V/m(2) and 3.4(5) x 10(20) V/m(2), respectively, me aning that the In and Cd ions are in the same lattice environment in t he forms of In3+ and Cd2+. Although these probes are considered to occ upy the Li sites, the above values of V-zz(lattice) are substantially different from the previously reported value for Li-7, 0.7 x 10(20) V/ m(2), which is ascribable to the structural relaxation around the prob e atoms. The temperature dependence of omega(Q) of In-117 indicates th at the In ion vibrates anisotropically about its equilibrium position at high temperatures, as has been argued for the Li ion In LiNbO3. [S0 163-1829(97)04942-4].