Low-temperature impedance spectroscopic analyses of ceramic electrodes based on Mo and Co co-doped SnO2

FERREIRA, DIEGO; VAZ, ISABELA; RUBINGER, RERO; BUONO, CAMILA; ROCHA, LEANDRO; PONCE, MIGUEL; LONGO, ELSON; SIMOES, ALEXANDRE; MOURA, FRANCISCO

Processing and Application of Ceramics

University of Novi Sad

Año: 2019 vol. 13 p. 360 - 367

1820-6131

Low resistive electrodes based on Co and Mo co-doped SnO2were prepared by the conventional solid-statereaction and sintered at 1250 °C for 2 h. Concentration of Co2O3precursor was unchanged (1 mol%), whileMoO3was varied (0.25, 0.50 to 0.75 mol%) to promote conductivity. The structural and microstructural char-acterization revealed that the samples have a rutile-type structure without secondary phases and large rutilegrains with low porosity. Electrical measurements on DC mode have shown a semiconductor behaviour of theSnO2samples doped with 0.25 and 0.75 at.% of Mo at temperatures below 50 K, indicating their suitability forlow-temperature electronic applications. Impedance measurements indicate reduced energy barriers of lessthan 1 meV formed between highly conductive crystallites for the SnO2samples doped with 0.25 and 0.75 at.%of Mo. The sample with Mo content of 0.50 at.% presented a higher energy barrier at a few hundredths of eV,with space charges at the crystallite boundaries.