Competing effects of Mn-doping and strain on electrical transport of NdNi1−xMnxO3 (0 ⩽ x ⩽ 0.10) thin films.

We have deposited NdNi_1−xMn_xO₃ (0 ⩽ x ⩽ 0.10) thin films on two different substrates, YAlO₃ (1 0 0) and NdGaO₃ (0 0 1), respectively, to explore the effects of Mn-doping with compressive and tensile strain. These films show metal–insulator transitions, except for two films with x = 0.10. The Hall coefficient measurements show that the majority of charge carriers are holes in these films. Increasing Mn-doping linearly decreases the temperature coefficient of resistance in the conducting temperature-region. The resistivity increases systematically with increasing Mn-doping in the films with tensile strain, whereas it non-monotonically decreases with doping in thin films with compressive strain. This study reveals competition and combination of different effects of the Mn-doping and of the strain, where the competition and the combination depend on the temperature-region and the type of strain. In addition to the effects of electronic configuration of Mn ions on the free carrier concentration, we find that the effects of Mn-doping on the resistivity are also mediated by the structure, and moulded under the influence of strain. The effects of Mn-doping and strain are distinguished and explained here. [ABSTRACT FROM AUTHOR]