Layered Perovskite-Like Oxides 0112 Type: Structure, Properties, and Possible Apllications

Abstract

Data available in the literature on layered LnAMe2O5+δ (Ln – rare-earth element (REE); A – alkaline element (AE) or alkali-earth element (AEE); Me – 3d–metal) oxides related to the 0112 (YBaCuFeO5) structural type are summarized and discussed. The methods of preparation, crystal structure and thermal stability of the LnAMe2O5+δ are described and their thermal expansion, magnetic and electrical properties are characterized. The influence of the REE and 3d–metal nature as well as the oxygen nonstoichiometry value on the structure and properties of these phases are analyzed. The influence of the oxygen sub-lattice state of LnAMe2O5+δ phases on their properties as well as the phase transitions taking place in these oxides in a wide temperature range are discussed. It is shown that large values of electrical conductivity and thermo–e.m.f. values of some LnAMe2O5+δ phases as well as presence in their structure of the weakly–bound (labile) oxygen causes possibility of their usage as materials for semiconducting chemical sensors of gases, oxidation catalysts of hydrocarbons, electrode materials for high-temperature electrochemical devices (chemical electrical supplies) as well as materials for high-temperature conversion of heat into electrical energy in thermoelectric generators (thermal electrical supplies).