As potential cathode materials Pr2-xSrxNiO4 +/-delta compositions with x=0.3 and 0.6 were prepared at 1300 degrees C in air and their electrical conductivity and oxygen non-stoichiometry were investigated in the temperature range 20-1000 degrees C and oxygen partial pressure (pO(2)) 1-21,000 Pa. Sr-doping allows partially to stabilize the Pr2NiO4 +/-delta structure, but some phase transitions were observed in spite of that. The electrical conductivity and the oxygen mobility of the Pr- and La-containing ceramic nickelates with K2NiF4- type structure are 10-15% higher for Pr2-xSrxNiO4-delta compounds at the same temperature and oxygen partial pressure. (c) 2006 Elsevier B.V. All rights reserved.