  We report on the substitution effect of Indium (In) at the Ag site of layered
oxychalcogenide La2O2Bi3Ag1-xInxS6. The Tc decreases with increasing In
concentration. A hump in the normal state resistivity at an anomaly temperature
(T*) near 180 K was observed for all the samples. The anomaly in the
resistivity at T* is indicating the possible occurrence of a
charge-density-wave (CDW) transition. The T* does not markedly change by In
doping. The x dependence of Seebeck coefficient suggests that carrier
concentration does not change by In doping. The EDX analysis indicates small
amount of Bi deficiency, which suggests that the Bi site is slightly
substituted by In. The CDW transition is robust against the In substitution at
Ag site, while Tc is decreasing due to the Bi site substitution by In. On the
basis of those analyses, we propose that the suppression of superconductivity
in the In-doped La2O2Bi3Ag1-xInxS6 system is caused by negative in-plane
chemical pressure effect and partial substitution of In for the in-plane Bi
site.
