title: The structural and physical properties of Ba(1-x)Sr(x)Fe(2)As(2) (0 ≤ x ≤ 1) and Ba(1-x)Sr(x)Fe(1.8)Co(0.2)As(2) (0 ≤ x ≤ 1).
abstract: Polycrystalline samples of Ba(1-x)Sr(x)Fe(2)As(2) (0≤x≤1) and Ba(1-x)Sr(x)Fe(1.8)Co(0.2)As(2) (0≤x≤1) have been synthesized by a solid state reaction method. Structural analysis by means of x-ray diffraction shows that the lattice parameters and unit cell volume decrease monotonically with the increase of x for Ba(1-x)Sr(x)Fe(2)As(2). The measurements of transport properties demonstrate that the average size of the Ba(Sr)-site cations could evidently influence the spin density wave (SDW) behavior in Ba(1-x)Sr(x)Fe(2)As(2) and superconductivity in Ba(1-x)Sr(x)Fe(1.8)Co(0.2)As(2) as well. The critical temperature for SDW (T(SDW)) increases with the Sr substitution for Ba in Ba(1-x)Sr(x)Fe(2)As(2) and, on the other hand, the superconducting T(c) decreases with the increase of Sr content in Ba(1-x)Sr(x)Fe(1.8)Co(0.2)As(2). The inhomogeneous distributions of Ba/Sr ions and structural distortions in Ba(0.5)Sr(0.5)Fe(2)As(2) have been investigated by transmission-electron microscopy (TEM) observations.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Wang
authors.forename: Huaixin
authors.initials: H
authors.lastname: Yang
authors.forename: Chao
authors.initials: C
authors.lastname: Ma
authors.forename: Huanfang
authors.initials: H
authors.lastname: Tian
authors.forename: Honglong
authors.initials: H
authors.lastname: Shi
authors.forename: Jiangbo
authors.initials: J
authors.lastname: Lu
authors.forename: Lunjie
authors.initials: L
authors.lastname: Zeng
authors.forename: Jianqi
authors.initials: J
authors.lastname: Li