Fig. 2: High-pressure resistance as a function of temperature at different pressures for the Ca10(Pt4As8)((Fe0.97Pt0.03)2As2)5 superconductors and corresponding fits by the forms of R = R′0 + A′T + B′T2.
a A□ (A□ = (w/l)(t/d)A′, here w and t are the width and the thickness of the sample, l is the distance between the electrodes, and d is an average distance between FeAs layers (see “Methods”) shows the maximum value (10.8) at 0.6 GPa for the S#1 surrounded by the pressure transmitting medium (PTM) of NaCl, where the normal state of the sample is in a pure SM state (α = 1), and its Tc displays the highest value. b–d A□ decreases with applied pressure in the pressure range of 3.5 GPa–10.1 GPa for the S#1, in the pressure range of which Tc is suppressed gradually. e–h A□ approaches zero and α = 2 for the S#1 in the pressure range of 13.0 GPa–20.4 GPa, in which the superconductivity is absent. i A□ = 12.8 at 1.1 GPa for the S#4 surrounded by the PTM of glycerin, where the normal state of the sample is also in a pure SM state (α = 1), and its Tc displays the highest value. j–l A□ declines upon increasing pressure for the S#4 in the pressure range of 3.5 GPa–10.8 GPa. m–p A□ = 0 and α = 2 for the S#4 in the pressure range of 12.8 GPa–19.6 GPa, in which the sample is no longer superconducting.
