Impurity effects on the electronic/magnetic ground states of perovskite manganites

Impurity effects on charge ordering (CO) as well as magnetic ground states in perovskite-type manganites are investigated. We found that the CO state becomes short-ranged with a small amount of impurities, in contrast to the impurity effects on the magnetic ordering without CO, c.g., the ferromagnetic (FM) state or the layered antiferromagnetic state. Such a short-ranged CO may play an important role in the competition between the FM stale and the CO slate.