Single crystals of SrFe2As2 grown using a self-flux solution method were characterized via x-ray, transport and magnetization studies, revealing a superconducting phase below T_c = 21 K characterized by a full electrical resistivity transition and partial diamagnetic screening. The reversible destruction and reinstatement of this phase by heat treatment and mechanical deformation studies, along with single-crystal X-ray diffraction measurements, indicate that internal crystallographic strain originating from c-axis-oriented planar defects plays a central role in promoting the appearance of superconductivity under ambient pressure conditions in ~90% of as-grown crystals. The appearance of a ferromagnetic moment with magnitude proportional to the tunable superconducting volume fraction suggests that these phenomena are both stabilized by lattice distortion.
@article{arxiv.0811.3940,
title = {Superconducting and ferromagnetic phases induced by lattice distortions in SrFe2As2},
author = {S. R. Saha and N. P. Butch and K. Kirshenbaum and J. Paglione},
journal= {arXiv preprint arXiv:0811.3940},
year = {2009}
}