Irreversibility line of an Ag-doped Hg-based superconductor

Abstract

The effect of doping with Ag of the bulk superconducting Hg 0.3 La 0.7 Ba 2 Ca 3 (Cu 1−x Ag x ) 4 O 10+δ , 0.1 x 0.3 phase (Hg-1234) is presented. The lattice parameter a = 3.824 Å remains constant, while parameter c was found to increase from c = 19.0225 Å (x = 0.0) to 19.08 Å (x = 0.3) with the addition of Ag. The variation of T c versus the c-parameter exhibits a cupola-shaped behavior. The irreversibility line is thermally activated. The logarithmic plot of H irr versus (1 − T irr /T c (0)) shows a crossover temperature reflecting a transition from two-to three-dimensional behavior with increasing temperature. Fitting of the results to different models is discussed. Thermally activated de-pinning according to Matsushita's formula gives the best fit.

Superconductivity in Crystallographically Disordered LaHg6.4

“…Mercury-based compounds (amalgams) have received a considerable amount of attention in the chemical community—these materials often host complex crystallographic arrangements 16 − 27 and display peculiar bonding features. 22 , 28 − 34 As a result, some of these materials show peculiar superconducting characteristics, 21 , 32 , 35 − 47 including high critical temperatures, which can be enhanced even further by the application of pressure. Some mercury-containing materials were even suggested to exhibit topologically nontrivial states.…”

“…Mercury-based compounds (amalgams) have received a considerable amount of attention in the chemical communitythese materials often host complex crystallographic arrangements − and display peculiar bonding features. ,− As a result, some of these materials show peculiar superconducting characteristics, ,,− including high critical temperatures, which can be enhanced even further by the application of pressure. Some mercury-containing materials were even suggested to exhibit topologically nontrivial states. − Moreover, peculiar magnetic correlations, brought on by the mixing of d and f orbitals, have been observed in several solid-state compounds. ,− Additionally, the application potential of some mercury-based materials has been discussed. , However, it is well-known that much care must be taken during the synthesis, handling, and characterization of mercury-based compounds, in particular rare earth metals’ mercuridesfrom toxicity concerns to their high chemical reactivityas these systems pose several experimental challenges. ,− The complexity of work on mercury-based materials is reflected in a low number of systems that have been discovered so far.…”