  The emerging Ni-based superconducting oxide thin films are rather intriguing
to the entire condensed matter physics. Here we report some brief experimental
results on transport measurements for a 14-nm-thick superconducting
Nd0.8Sr0.2NiO2/SrTiO3 thin-film heterostructure with an onset transition
temperature of ~9.5 K. Photoluminescence measurements reveal that there is
negligible oxygen vacancy creation in the SrTiO3 substrate during thin-film
deposition and post chemical reduction for the Nd0.8Sr0.2NiO2/SrTiO3
heterostructure. It was found that the critical current density of the
Nd0.8Sr0.2NiO2/SrTiO3 thin-film heterostructure is relatively small, ~4x10^3
A/cm2. Although the surface steps of SrTiO3 substrates lead to an anisotropy
for in-plane resistivity, the superconducting transition temperatures are
almost the same. The out-of-plane magnetotransport measurements yield an upper
critical field of ~11.4 T and an estimated in-plane Ginzburg-Landau coherence
length of ~5.4 nm. High-field magnetotransport measurements up to 50 T reveal
anisotropic critical fields at 1.8 K for three different measurement geometries
and a complicated Hall effect. An electric field applied via the SrTiO3
substrate slightly varies the superconducting transition temperature. These
experimental results could be useful for this rapidly developing field.
