Effect of tensile stress on the in-plane resistivity anisotropy in BaFe2As2
cond-mat.supr-con
/ Authors
E. C. Blomberg, A. Kreyssig, M. A. Tanatar, R. Fernandes, M. G. Kim, A. Thaler, J. Schmalian, S. L. Bud'ko, P. C. Canfield, A. I. Goldman
and 1 more author
/ Abstract
The effect of uniaxial tensile stress and the resultant strain on the structural/magnetic transition in the parent compound of the iron arsenide superconductor, BaFe$_2$As$_2$, is characterized by temperature-dependent electrical resistivity, x-ray diffraction and quantitative polarized light imaging. We show that strain induces a measurable uniaxial structural distortion above the first-order magnetic transition and significantly smears the structural transition. This response is different from that found in another parent compound, SrFe$_2$As$_2$, where the coupled structural and magnetic transitions are strongly first order. This difference in the structural responses explains the in-plain resistivity anisotropy above the transition in BaFe$_2$As$_2$. This conclusion is supported by the Ginzburg-Landau - type phenomenological model for the effect of the uniaxial strain on the resistivity anisotropy.