1203.1834 (Y. Texier et al.)

NMR in the 245 iron-selenides Rb0.74Fe1.6Se2: phase separation between
an antiferromagnet and a superconducting Rb0.3Fe2Se2    [PDF]

Y. Texier, J. Deisenhofer, V. Tsurkan, A. Loidl, D. S. Inosov, G. Friemel, J. Bobroff

77Se and 87Rb nuclear magnetic resonance (NMR) experiments on Rb0.74Fe1.6Se2 demonstrate phase separation between a majority antiferromagnetic (AF) and a minority metallic/superconducting (SC) phase. The AF spectrum is compatible with the AF Fe-vacancy ordered structure reported previously. The SC spectrum displays a very small linewidth, implying the absence of Fe vacancies and any trace of AF order. Its composition is deduced from intensity measurements to be Rb0.3(1)Fe2Se2, i.e. 0.15 electrons/Fe, which makes superconductivity in the 245 family similar to the other Fe-based superconductors.

View original: http://arxiv.org/abs/1203.1834