Magnetization and electronic structure of polycrystalline La1-xCaxMnO3 (x=0.19, 0.17)
The discovery of colossal magneto-resistance (CMR) 1 in perovskite manganites has attracted intensive attention. Various models and theories have been proposed to explain the abundant physical properties in perovskite manganites. As to CMR effect in La1-xCaxMnO3 (LCMO), Griffiths phase (GP) 2 has been brought up to account for the related phenomena near transition temperature recently. The nonexistence of GP in x=0.20 LCMO single crystal with CMR effect brought about the doubt for the relationship between GP and CMR effect 3. That whether concentration x=0.20 is the critical doping concentration of GP in LCMO system becomes an important discussion point. Jiang et al. 4 elaborated the situation of GP in the concentration region 0.18 x≤0.27, which proved that La0.81Ca0.19MnO3 single crystal exhibits GP feature. In our work, polycrystalline samples of LCMO system (x=0.1, 0.15, 0.17, 0.19, 0.20, 0.21) have been studied in term of GP. And all samples exist GP because of the higher degree of disorder 5.GP can be impacted from many kinds of factors, like quenched disorder caused by A-site doping 2, 6, grain size 7, external field 8, etc. However, the nature of existence of GP in LCMO system (x≤0.21) is under investigation. Therefore, the studies of magnetization and electronic structure of LCMO system can be useful for further understanding the nature of GP in LCMO system (x≤0.21).
Zhang Hongguang Li Yongtao Chen Lingshan Liu Hao Chen Yuanyuan Chen Kai Dong Xueguang Li Qi
Department of Physics, Southeast University, Nanjing, 211189, P.R.China.
国际会议
2010 8th International Vacuum Electron Sources Conference and NANOcarbon(第八届真空电子源和纳米碳国际会议)
南京
英文
597-598
2010-10-14（万方平台首次上网日期，不代表论文的发表时间）