Improvement in the sintering and electrical properties of strontium- and magnesium-doped lanthanum gallate by MoO3 dopant

- MoO3 was added to LSGM sample and plays the role as sintering aid.
- The phase purity and ionic conductivity of the sample was improved by adding MoO3.
- The 2 at.% MoO3-doped LSGM specimen exhibited the best property.

The LSGM powders by doping 0-2.5 at.% of MoO3 were synthesized and investigated. The microstructure and electrical properties of the samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and electrochemical impedance spectroscopy (EIS) respectively. The results showed that the phase purity, densification and conductivity of the LSGM samples could be improved by a proper addition of MoO3. The LSGM specimen by doping 2 at.% MoO3 exhibited the best phase purity, the best density, the largest grain size and the lowest activation energy. Moreover, it was found that the conductivity of the LSGM by doping 2 at.% MoO3 was 3.91 × 10−4 S cm−1 at 450 °C, which was 2.82 times as high as LSGM without MoO3 doping. Moreover, the thermal expansion coefficient of the LSGM-2Mo sample changed little by MoO3 doping. Therefore, the MoO3 doped LSGM may be a potential electrolyte material for anode-supported solid oxide fuel cells (SOFCs) without requiring buffer layer between anode and electrolyte.