[ ](R=Pr, Nd, and Sm) was synthesized and their magnetic properties and charge ordering(CO) transition related with lattice dynamics and oxygen vacancy were systematically investigated. The charge disproportion ation(CD) in (R=Pr,Nd) was in which two kins of iron with valence state and were found with ratio of 2:1. In this charge ordering state a sequence of exists aligned along the [111] direction of the pseudocubic perovskite structure. The charge ordering exist in distorted structure involving hybridization. The disordering phases coexist in distorted structure as temprature in creases that is controlled amount of oxygen vacancy. The magnetic hyperfine fields indicate charge tranfering temperature as it dissapeared drastically.

• 엄영랑 | Uhm Young-Rang
• 이창규 | Rhee Chang-Kyu
• 김철성 | Kim Chul-Sung