Structural and Electrical Properties of Layered Pervoskite Manganites Nd2-2xSr1+2xMn2 O7 (x=0.25, 0.3, 0.4)
来源期刊：JOURNAL OF RARE EARTHS2007年第6期
论文作者：Zhao Yong Pei Jian Chen Gang Xian Hengze
Key words：layered perovskite manganites; crystal structure; FT-IR; resistivity; rare earths;
Abstract: Tetragonally layered perovskite manganites of Nd2-2xSr1+2xMn2O7 (x=0.25, 0.3, 0.4) were fabricated by using solid-state reaction technique.Structural characterization of the compounds was investigated by X-ray diffraction (XRD) and FT-IR absorption spectra.The XRD patterns revealed that all the samples were single phase.X-ray photoemission spectroscopy (XPS) was used to investigate their electronic structures.It was found that manganese was in mixed states of Mn3+ and Mn4+ whereas lattice oxygen and chemical absorbed oxygen were existed in all the samples.The high temperature electrical properties of Nd2-2xSr1+2xMn2O7 (x=0.3, 0.4) were measured by standard four-probe technique.The results showed that both compounds had semi-conductivity behavior in the temperature range of 300～1073 K, and the electrical conduction was dominated by thermally activated behavior above 500 K.
Zhao Yong1，Pei Jian1，Chen Gang1，Xian Hengze1
(1.Department of Applied Chemistry,Harbin Institute of Technology,Harbin 150001,China)
Abstract:Tetragonally layered perovskite manganites of Nd2-2xSr1+2xMn2O7 (x=0.25, 0.3, 0.4) were fabricated by using solid-state reaction technique.Structural characterization of the compounds was investigated by X-ray diffraction (XRD) and FT-IR absorption spectra.The XRD patterns revealed that all the samples were single phase.X-ray photoemission spectroscopy (XPS) was used to investigate their electronic structures.It was found that manganese was in mixed states of Mn3+ and Mn4+ whereas lattice oxygen and chemical absorbed oxygen were existed in all the samples.The high temperature electrical properties of Nd2-2xSr1+2xMn2O7 (x=0.3, 0.4) were measured by standard four-probe technique.The results showed that both compounds had semi-conductivity behavior in the temperature range of 300～1073 K, and the electrical conduction was dominated by thermally activated behavior above 500 K.
Key words:layered perovskite manganites; crystal structure; FT-IR; resistivity; rare earths;
【全文内容正在添加中】
