Table 2 The coordinates of invariant points in the systems HfO2-Lng0g and ZrO2-LngO3 Ln? 03 Systems HfO2-Ln2Oa Systems ZrO2-Ln2O3 onic radius, by Ref(nm) mperature of Ref(nm) Ahrrenius(nm) Tectic HtO? peritectic HfO2 peritectic°C Tectic eutectIc°C) 0.1014 0.10068 ~2200 0.102 0.0428 224012 2130 Tb ~2350 0.089 236014 008702 2350 0.087 0848 .15 0.084162366 Table 2 E.R. Andrievskaya / Journal of the European Ceramic Society 28 (2008) 2363–2388 The coordinates of invariant points in the systems HfO2–Ln2O3 and ZrO2–Ln2O3 Ln2O3 Systems HfO2–Ln2O3 Systems ZrO2–Ln2O3 58 Ionic radius, by Ahrrenius (nm) Ref (nm) Composition eutectic HfO2 (mol%) Temperature of eutectic (◦C) Composition of peritectic HfO2 (mol%) Temperature of peritectic (◦C) Ref (nm) Composition eutectic Temperature of eutectic (◦C) La 0.114 0.1014 35 2070 – – 0.10068 0.37 1980 77 2330 103 Ce 0.107 0.0983 30 – – – – – – Pr 0.106 0.09816 28 2125 45 ∼2200 0.09704 0.32 2100 75 2420 103 Nd 0.104 0.09698 27 2140 103 65 2450 0.0962 0.30 2120 ∼48 ∼2270 Sm 0.102 0.09428 26 2240 122 67 2550 0.0945 0.25 2180 ∼52 ∼2335 Eu 0.098 0.093 25 2150 139 0.0928 0.26 2130 196 Gd 0.097 0.09282 22 2310 122 – – 0.09244 0.24 2260 Tb 0.093 0.09015 19 2300 122 ∼30 ∼2350 0.08955 0.23 2250 Dy 0.092 0.08934 19 2310 122 ∼32 ∼2390 0.08892 0.22 2280 Ho 0.091 0.08905 15 2340 154 ∼31 ∼2380 0.08866 0.18 2300 Y 0.092 0.08976 16 2400 154 ∼30 2430 0.08976 0.16 2360 Er 0.089 0.08735 15 2360 154 ∼30 ∼2400 0.08702 0.18 2350 Tm 0.087 0.08574 14 2380 154 ∼33 ∼2460 – – – Yb 0.086 0.08496 13 2430 154 ∼35 ∼2500 0.0848 0.15 2410 Lu 0.085 0.08416 – – 12 2510 154 –– –