Publications Repository - Gdańsk University of Technology

The single phase lanthanum orthoniobate with tetragonal structure has been synthesized by the means of mechanosynthesis method. The studies have shown the crystal structure of La0.98Ca0.02NbO4 depends on the synthesis stage. The samples were predominantly in the tetragonal phase with a trace amount of the monoclinic phase. The SEM studies of morphology and microstructure have shown nanocrystallinity of the materials. The Raman studies showed the significant difference between the Raman spectra of nano- and microcrystalline La0.98Ca0.02NbO4. A decrease of Debye temperature, shown a change of thermal properties due to the presence of nano-sized particles in La0.98Ca0.02NbO4. Electrical characterization results suggest the protons are predominant charge carries in the material for the whole measured range of temperature and shows the total conductivity value of 4.0 × 10−5 S cm−1 at 600 °C in wet air. The calculated activation energies were equal to (0.81 ± 0.04) eV under dry and (0.73 ± 0.06) eV under humidified conditions. That indicates that nanostructuring was successfully stabilized the high-temperature tetragonal phase.

Authors

• dr inż. Tadeusz Miruszewski link open in new tab ,
• dr inż. Piotr Winiarz link open in new tab ,
• dr inż. Kacper Dzierzgowski link open in new tab ,
• mgr inż. Katarzyna Wiciak link open in new tab ,
• mgr inż. Krzysztof Zagórski link open in new tab ,
• Andrzej Morawski,
• dr hab. inż. Aleksandra Dorota Mielewczyk-Gryń link open in new tab ,
• dr inż. Sebastian Lech Wachowski link open in new tab ,
• Judyta Strychalska-Nowak link open in new tab ,
• Miroslaw Sawczak,
• prof. dr hab. inż. Maria Gazda link open in new tab