Rodgers, Jennifer A. Penny, George B.S. Marcinkova, Andrea Bos, Jan-Willem G. Sokolov, Dmitry A. Kusmartseva, Anna Huxley, Andrew D. Attfield, J. Paul Suppression of the superconducting transition of R FeAsO1-x Fx (R=Tb, Dy, and Ho) A suppression of superconductivity in the late rare-earth R FeAsO1-x Fx materials is reported. The maximum critical temperature (Tc) decreases from 51 K for R=Tb to 36 K for HoFeAsO0.9 F0.1, which has been synthesized under 10 GPa pressure. This suppression is driven by a decrease in the Fe-As-Fe angle below an optimum value of 110.6°, as the angle decreases linearly with unit-cell volume (V) across the R FeAsO1-x Fx series. A crossover in electronic structure around this optimum geometry is evidenced by a change in sign of the compositional d Tc /dV, from negative values for previously reported large R materials to positive for HoFeAsO0.9 F0.1. © 2009 The American Physical Society. untagged;Physical Sciences not elsewhere classified 2015-04-24
    https://repository.lboro.ac.uk/articles/journal_contribution/Suppression_of_the_superconducting_transition_of_R_FeAsO1-x_Fx_R_Tb_Dy_and_Ho_/9408986