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Pressure-induced volume-collapsed tetragonal phase of CaFe 2 As 2 as seen via neutron scattering



A. Kreyssig, Mark Green, Y. Lee, G. D. Samolyuk, Pawel Zajdel, Jeffrey Lynn, S. L. Bud'ko, M. S. Torikachvili, N. Ni, S. Nandi, Juscelino Leao, Sarah Poulton, D. N. Argyriou, B. N. Harmon, R. J. McQueeny, P. C. Canfield, A. I. Goldman


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 nonmagnetic 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.
Physical Review B


neutron diffraction, magnetic order, structural phase transition, pressure, iron-based superconductor


Kreyssig, A. , Green, M. , Lee, Y. , Samolyuk, G. , Zajdel, P. , Lynn, J. , Bud'Ko, S. , Torikachvili, M. , Ni, N. , Nandi, S. , Leao, J. , Poulton, S. , Argyriou, D. , Harmon, B. , McQueeny, R. , Canfield, P. and Goldman, A. (2008), Pressure-induced volume-collapsed tetragonal phase of CaFe 2 As 2 as seen via neutron scattering, Physical Review B, [online],, (Accessed April 23, 2024)
Created November 24, 2008, Updated March 25, 2024