“…[20,25] Although the thermal conductivity dependence on the size of the B-site (i.e., Zr in Ln 2 Zr 2 O 7 ) is stronger, the size of the A-site also has an effect, and simulations predict the lowest thermal conductivities for samarium, europium, and gadolinium on the A-site. [57] [16,18,55,56,[58][59][60][61] and 8, [16,56,[61][62][63][64][65][66][67] [67] are similarly in the lower range of the YSZ materials, as shown in Figure 9. Gd 2 Zr 2 O 7 and Sm 2 Zr 2 O 7 have received the most attention as candidate thermal barrier coating materials due to their good combination of thermal and mechanical properties.…”