Internal pressure effect on some manganite oxides

In this paper, we investigate the effects of internal pressure an various c olossal magnetoresistance materials. By substituting a smaller ion for a la rger ion, one can exert the lattice pressure to the crystal structures and, hence, changes the physical properties of these materials. Since the chara cteristic of the perovskite oxides is a layered structure, the created stra ins owing to the substitutions are mostly anisortropy and the resulting cha nges are presumably complicated. We have found that the substitutions can f ine-tune the electronic structures of various materials and can result in m any interesting phenomena.