In a recent Nature Physics publication scientists from J. F. Mitchell's group at Argonne NL and their colleagues present the growth procedure and analysis results of the closest analogues to high-Tc cuprates yet reported: the nickelate Pr₄Ni₃O₈. Single crystals of this “promisig candidate for unconventional superconductivity” could be obtained after the high-pressure optical floating zone growth and subsequent reduction in a H2/Ar atmosphere. The authors “have shown, that bulk R438 crystals possess a combination of traits that are widely considered as important ingredients for high-Tc superconductivity in cuprates. “ This metallic square-planar nickelate is “a singularly promising candidate for high-Tc superconductivity if electron doping could be achieved.” We are very excited to hear the results of the doping attempts!

https://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys4149.html