Limiting current oxygen sensor based on Y, In co-doped SrTiO₃ as a dense diffusion barrier layer

A novel dense diffusion barrier material (Y_xSr_1−xTi_0.9In_0.1O_3−δ (x = 0.03, 0.05, 0.07)) was prepared by using a sol-gel method. The crystal structure, microstructures, electrical conductivity and ionic conductivity of barrier material were characterized. The results show that the samples exhibit the formation of cubic perovskite structure phase. The increase of Y-doping amount on A-site improved electrical conductivity and sinterability of materials. A limiting current oxygen sensor based on Y_0.07Sr_0.97Ti_0.9In_0.1O_3–δ as a dense diffusion barrier shows excellent sensing performance. The linear relationship between limiting current logI_L and 1000/T can described logI_L = 4.603,8 − 3.847,5·1,000/T. At 750 °C, 0.25% ≤ x(O₂) ≤ 5.0%, the linear relationship between limiting current (I_L) and oxygen amount (x(O₂)) can described as I_L = 7.047,6 + 3.875,1·x(O₂).