Systematic Study on Crystal Structure and Properties of FeSr2LnCu2O7+δ (Ln: La, Nd, Sm, Eu, Gd, Dy, Ho, Er, and Yb).

✍ Scribed by L. T. Yang; J. K. Liang; Q. L. Liu; H. M. Fan; G. B. Song; X. M. Feng; H. F. Yang; G. H. Rao

• Publisher: John Wiley and Sons
• Year: 2004
• Weight: 61 KB
• Volume: 35
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.200411005

✦ Synopsis

2004

Structure

Structure D 2000

Systematic Study on Crystal Structure and Properties of FeSr 2 LnCu 2 O 7+δ (Ln: La, Nd, Sm, Eu, Gd, Dy, Ho, Er, and Yb). -As revealed by powder XRD, the crystal structure of the title compounds, synthesized by solid state reactions, exhibits a transition from a tetragonal system with space group P4/mmm for light rare earths (Ln: La, Nd, Sm, Eu, Gd) to an orthorhombic system with space group Pmmm for heavy rare earths (Ln: Dy, Ho, Er, Yb). The site distribution of Fe is monitored by room temperature Moessbauer spectroscopy. The magnetic susceptibility of the samples changes with temperature in a Curie-type manner. Resistance measurements indicate that the compounds have a semiconductor-like behavior and their band gap is related to their structural type and the radius of the rare earth ions.