<p>In this paper we examine the effects of doping phosphate into yttrium, ytterbium, and thulium doped BaPrO₃. Through phosphate doping it is possible to achieve high levels of Y/Yb/Tm, and we show that it is possible to completely replace all the Pr with this co-doping strategy, albeit such phases contained small impurities. The samples were analysed through a combination of X-ray diffraction, TGA, Raman spectroscopy and conductivity measurements. Conductivity data indicated that these heavily Y/Yb/Tm doped samples, however, showed lower conductivities than reported for previously for low levels (10-20%) of Y/Yb doping. </p>

<p>In this paper we examine the effects of doping phosphate into yttrium, ytterbium, and thulium doped BaPrO₃. Through phosphate doping it is possible to achieve high levels of Y/Yb/Tm, and we show that it is possible to completely replace all the Pr with this co-doping strategy, albeit such phases contained small impurities. The samples were analysed through a combination of X-ray diffraction, TGA, Raman spectroscopy and conductivity measurements. Conductivity data indicated that these heavily Y/Yb/Tm doped samples, however, showed lower conductivities than reported for previously for low levels (10-20%) of Y/Yb doping. </p>