Electrical screening of ternary NiO-Mn ₂ O ₃ -Co ₃ O ₄ composition spreads

The compositional optimization of infrared-transparent conducting oxides was performed using high throughput screening of combinatorial libraries. Complete ternary composition spreads of NiO-Mn ₂ O ₃ -Co ₃ O ₄ alloys were deposited onto conducting Nb-doped SrTiO ₃ substrates using the pulsed laser deposition technique. Resistance-temperature relations of each composition in the spread were determined using a custom-designed scanning probe. The binary NiCo ₂ O ₄ oxide showed the lowest electrical resistivity of about 0.1 Ω cm but unacceptably large resistance-temperature dependence (3.5%/°C). Electrically conducting ternary alloys along the line Mn _0.45 Ni _0.63 Co _1.92 O ₄ -Mn _0.60 Ni _0.72 Co _1.68 O ₄ -Mn _0.69 Ni _0.81 Co _1.50 O ₄ exhibited much lower temperature sensitivity (of about 1.5%/°C) as well as electrical resistance comparable to that of NiCo ₂ O ₄ . From this screening we propose new compounds for the thin-film ITCO sensors.