PROCESSING OF (La,Sr)(Ga,Mg)O-3 SOLID ELECTROLYTE USING AN ENHANCED SOLID STATE TECHNIQUE

Sr and Mg doped lanthanum gallate perovskites (La1-xSrxGa1-yMgyO3-delta) shortened as LSGM are promising electrolyte materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). The evolution of secondary phases, such as LaSrGa3O7 has been identified to be a problem in the preparation of LSGM. Actually, no mater what technical preparation route was adopted (wet-based or solid state-based method) the presence of the secondary phases, accompanying the main phase LSMG was reported. The results regarding an attempt to obtain pure Sr and Mg doped LaGaO3 ceramics using a specific annealing treatment was reported in this work. The obtained ceramics were characterized using different techniques. Thermal analyses (DTA/TG) on the stoichiometric raw mixture and dilatometric measurements on sintered bodies were performed. Morphological and structural aspects were investigated by means of X-ray diffractometry, FT-IR spectroscopy and scanning electron microscopy. The electrical behavior of the obtained ceramic was characterized by complex impedance spectroscopy. Choosing an appropriate annealing program, almost pure Sr and Mg doped LaGaO3 can be obtained.