Blacklight sintering of BaZrO3-based proton conductors

Acceptor-doped BaZrO₃, a ceramic proton conductor, is well researched for use in solid oxide fuel cells due to its proton conductivity and chemical stability. A major drawback of the material is the difficulty of sintering as it requires high sintering temperatures and long heating times (> 1600 °C, 24 h). An emerging sintering technology to mitigate this challenge is blacklight sintering, which uses a high-powered blue or UV light source to heat ceramics extremely fast leading to short sintering times and reduced energy demand. In this work, BaZr_0.8Y_0.2O_3-δ (BZY20) and BaZr_0.8Y_0.1Sc_0.1O_3-δ (BZY10Sc10) were blacklight-sintered with a high-power blue laser in under four minutes. Even though the resulting samples have a gradient from large to small grains and structurally disordered grain boundaries, the proton conductivity is comparable to conventionally sintered samples. Hence, blacklight sintering is a promising technology with the potential to sinter BaZrO₃ much faster, while saving energy.