リン酸ランタン系セラミックスのプロトン導電性 Protonic Conduction in LaPO_4-based Ceramics
Significant protonic conduction has been found at high temperature in LaPO<SUB>4</SUB>-based ceramics, in which protons are considered to dissolve as defects in the presence of hydrogen-containing gases. This report describes electrolyte properties of 5mol% Sr-substituted LaPO<SUB>4</SUB>. In air, this material can be regarded as a pure protonic conductor at 600°C when P<SUB>H2O</SUB>>1kPa, and at 700°C when P<SUB>H2O</SUB>> 3kPa. At high temperature, low P<SUB>H2O</SUB>, and high P<SUB>O2</SUB>, the material shows mixed conduction by protons and electron holes. The contribution of electron hole conduction to the total conductivity becomes significant as temperature increases, P<SUB>O2</SUB> increases, and P<SUB>H2O</SUB> decreases, although protonic conduction is still dominant even at 900°C in wet air.
粉体および粉末冶金 46(3), 207-211, 1999-03-15
Japan Society of Powder and Powder Metallurgy