Fabrication and properties of c-axis Hg-1223 superconducting thin films

Unprecedented high irreversibility line in the nontoxic cuprate superconductor (Cu,C)Ba 2 Ca 3 Cu 4 O 11+δ

“…For films and crystals, the data when H || c axis are used for comparison, since it is believed that the critical current density with magnetic field parallel to c axis or the weak links limit the irreversibility lines in the polycrystalline samples. From the literature, one can find that the irreversibility fields at 77 K are ~4 T (Hg-1212) ( 23 ), ~6 T (Hg-1223) ( 24 ), ~2 T (Hg-1234) ( 25 ), and ~3 T (Tl-1223) ( 26 ), which are below the values of our present sample. We also checked the infinite layer system (Sr 1− x Ca x ) 1− y CuO 2 with T c ≈ 110 K ( 27 ), and there is quite little data about the irreversibility lines of this system perhaps because most of the samples have not been made to a perfect state.…”

“…This may be induced by the difference of the material morphologies inside the sample. We have gone through the literature that we could collect for the Hg- or Tl-based systems, including that for Hg-1212 ( 23 ), Hg-1223 ( 24 ), Hg-1234 ( 25 ), and Tl-1223 ( 26 ), and found that none of these materials has the irreversibility line beyond the present system (Cu,C)-1234. For films and crystals, the data when H || c axis are used for comparison, since it is believed that the critical current density with magnetic field parallel to c axis or the weak links limit the irreversibility lines in the polycrystalline samples.…”

Transport properties of (Hg,M)-12(n-1)n (M=Re,Mo; n=2,3) superconducting thin films

“…The details of the procedure, in particular for (Hg, Re)-1223 thin films, have been described elsewhere [9]. Amorphous HgO/Mo.lBaaCaCu?OY (M == Re, MO) multilayer precursor films were prepared by PLI) using a KrF excimer laser (A = 248 nm).…”

“…We have recently succeeded in fabricating highly c-axis oriented (Hg, Re)-1223 thin films using HgO/Re-Ba-Ca-Cu-0 multilayer precursor films prepared by PLD and reported that the Re substitution improves the film morphology as well as the superconducting properties [8], [9]. Furthermore, highperformance bicrystal grain boundary junctions and dc SQUIDs have been successfully fabricated using (Hg, Re)-1212 thin films prepared similarly [lo].…”

Role of the mercury pressure during reaction synthesis of Hg(Re)-based superconducting films

“…In this case the superconducting phase was formed by a vapour-solid reaction. Some groups reported the use of the two pellets (unreacted Hg-free (Re)-Ba-CaCu-O and unreacted Hg, Re-Ba-Ca-Cu-O) for the mercuration to obtain a stable mercury vapour flow [11][12][13]. To the best of our knowledge, no publication reports on preparing higher superconducting phases (Hg-1212, Hg-1223) via a vapor-solid reaction or using the mercuration with no contact between the precursor film and the mercury source.…”