Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen via neutron scattering

Kreyssig, A.; Green, M. A.; Lee, Y.; Samolyuk, G. D.; Zajdel, P.; Lynn, J. W.; Bud'ko, S. L.; Torikachvili, M. S.; Ni, N.; Nandi, S.; Leao, J.; Poulton, S. J.; Argyriou, D. N.; Harmon, B. N.; Canfield, P. C.; McQueeney, R. J.; Goldman, A. I.

Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen via neutron scattering

Authors

Description

Recent investigations of the superconducting iron-arsenide families have highlighted the role of pressure, be it chemical or mechanical, in fostering superconductivity. Here we report that CaFe2As2 undergoes a pressure-induced transition to a non-magnetic, volume "collapsed" tetragonal phase, which becomes superconducting at lower temperature. Spin-polarized total-energy calculations on the collapsed structure reveal that the magnetic Fe moment itself collapses, consistent with the absence of magnetic order in neutron diffraction.
accepted for publication in Phys. Rev. B