Interlayer distance and magnetic properties of Hg-based superconductors

Muon spin relaxation in Re-substitutedHgA2Can−1Cu

“…In Fig. 6 23 In summary, the present SR data on Re-substituted n ϭ2 and nϭ3 Hg-based superconductors, lead to T c () values that fall onto the universal Uemura line; therefore they do not provide any indication of Re-induced reduced anisotropy metallization of the interlayers, as earlier suggested. On the other hand, analyses of our data and that from literature allow to suggest a relevant role of the lattice contraction when substituting Ba by Sr, both on the observed ͑and thus on n s /m*) and the irreversibility line.…”

Sol–gel synthesis, structural and superconducting properties of (Hg1−ySey)Sr2(Y1−xCax)Cu2O6+δ

“…For the nX3 members, (Hg,M)Sr 2 Ca nÀ1 Cu n O 2n+2+d can only by synthesized under high pressure [27,44]. These Hg/Sr compounds were found to be chemically stable in open air and to have higher irreversibility fields compared with Hg/Ba ones [45][46][47].…”

Effect of Sr-for-Ba isovalent substitution on the local structure, hole distribution and magnetic irreversibility of Cu(Ba,Sr)2YbCu2O6.95(2)

“…It induces a contraction in BB, and might therefore be expected to improve the H irr characteristics. Quite importantly, for the Hg-based HTSCs replacing the larger Ba with the smaller Sr was proven to be an effective way to enhance the H irr values [9,[17][18][19] [20]. In fact, the first observation of the decrease in the critical current (J c ) characteristics in Cu-1212 with Sr substitution is from 1991 by Parent and Moreau [21].…”

“…Considering the crystal structure of HTSCs [2], i.e. piling up of a superconductive block (SB) and a nonsuperconductive blocking block (BB ) along the c-axis direction, the ways so-far suggested for enhancing the H irr characteristics are roughly classified into two categories: ( i) increasing the overall hole -doping level [3][4][5] to enhance the thermodynamical stability of magnetic fluxons in SB, and (ii) enhancing the conductivity of BB [6][7][8] and/or decreasing the thickness of BB [8][9][10][11] to improve the correlation of fluxons (through BB) between two adjacent SBs. In general, the H irr characteristics of HTSCs have been discussed with respect to electromagnetic anisotropy (γ 2 ) such that lowering the anisotropy enhances the H irr characteristics [1,8,12].…”