Switching of majority charge carriers by Zn-doping in NdNiOthin films.

We have studied the effects of Zn-doping on the structural and electronic properties of epitaxial NdNiO3 thin films grown on single-crystal LaAlO3 (001) (LAO) substrates by pulsed laser deposition. The films are deposited in two sets, one with variation in Zn-doping, and another with variation in thickness for undoped and 2% Zn doping. The experimental investigations show that Zn occupies Ni-site and that the films are grown with an in-plane compressive strain on LAO. All the films show metal to insulator transitions with a thermal hysteresis in the temperature-dependent resistivity curves except 5% Zn doped film, which remains metallic. The theoretical fits show non-Fermi liquid (NFL) behaviour, which gets influenced by Zn-doping. The Hall resistance measurements clearly show that Zn doping causes injection of holes in the system which affects the electronic properties as follows: i) the metallic conduction increases by two factors just by 0.5% Zn doping whereas, 5% doping completely suppresses the insulating state, ii) a reversal of sign of Hall coefficient of resistance is observed at low temperature.