Electrical properties and aging behavior of nickel manganite thin films co-doped with Cu and Zn annealed at low temperature

Abstract

Nickel-manganite-based thin films with a negative temperature coefficient of resistance (NTCR) characteristic were prepared from (Ni 0.2 Mn 2.8– x Cu x )Cl 2 (0.010£ x £0.040) solutions using the liquid flow deposition (LFD) method. The influence of Cu on the electrical properties of the films annealed at 400 °C was investigated. Adding Cu ( x = 0.025) was found to quite effectively lower the electrical resistivity ( ρ ) of the films to 200 W cm, whereas their sensitivity behavior was significantly degraded. Interestingly, the absolute temperature coefficient of resistance ( TCR ) of the films was enhanced by further adding 0.01 mol Zn along with Cu, without a remarkable increase in ρ . TCR = 2.98% K – 1 and ρ = 880 W cm at room temperature were attained for the Zn-containing specimen with 0.020 mol Cu doping. Moreover, the films with (Zn,Cu) co-doped compositions showed a much higher electrical stability than the Zn-free films.