1204.4542 (Z. W. Wang et al.)

Phase separation and stripe patterns in K0.8Fe1.6+xSe2 superconductors    [PDF]

Z. W. Wang, Z. Wang, Y. J. Song, C. Ma, H. L. Shi, Z. Chen, H. F. Tian, H. X. Yang, G. F. Chen, J. Q. Li

Structural investigations on the K0.8Fe1.6+xSe2 superconducting materials have revealed remarkable micro-stripes arising evidently from the phase separation. Two coexisted structural phases can be characterized by modulations of q1 = 1/5[a*+3b*], the antiferromagnetic phase K0.8Fe1.6Se2, and q2 = 1/2[a*+b*], the superconducting phase K0.75Fe2Se2, respectively. These stripe patterns likely result from the anisotropic assembly of superconducting particles along the [110] and [1-10] direction. In addition to the notable stripe structures, a nano-scale phase separation also appears in present superconducting system as clearly observed by high-resolution transmission electron microscopy. Certain notable experimental data obtained in this heterogenous system can be quantitatively explained by the percolation scenario.

View original: http://arxiv.org/abs/1204.4542