Photoinduced IR absorption in (La(1-x)Sr(x)Mn)(1-\delta)O3: changes of the anti-Jahn-Teller polaron binding energy with doping

摘要

Photoinduced IR absorption was measured in (La(1-x)Sr(x)Mn)(1-\delta)O3. Amidinfrared peak centered at ~ 5000 cm$^{-1}$ was observed in the x=0antiferromagnetic sample. The peak diminishes and softens as hole doping isincreased. The origin of the photoinduced absorption peak is atributted to thephoton assisted hopping of anti-Jahn-Teller polarons formed by photoexcitedcharge carriers, whose binding energy decreases with increasing hole doping.The shape of the peak indicates that the polarons are small.