Structure and oxygen storage/release capacities of Dy$_{1-x}$Y$_{x}$MnO$_{3+\delta }$ (0 $\le $ x $\le $ 1)*

Synthesis, oxygen storage/release capacities (OSC), oxygen absorption/desorption rates, and structural properties of Dy$_{1-x}$Y$_{x}$MnO$_{3+\delta }$ (0 $\le $ x $\le $ 1) have been studied by x-ray and neutron powder diffraction, dilatometry, and thermogravimetric analysis. These materials have been found to have excellent reversible OSC at low-temperatures of 200 - 375\r{ }C and various oxygen partial-pressures, making them potential candidates for oxygen sorbents in novel gas separation methods such as thermal swing absorption and thermal-automatic recovery processes. The OSC of the Dy$_{1-x}$Y$_{x}$MnO$_{3+\delta }$ system relies on the difference in oxygen content of a reversible phase transitions between hexagonal P63cm ($\delta $ = 0) and a previously unreported stable phases of this system (0 $<$ $\delta \quad <\quad 0.5)$ and pyrochlore Fd3m [$\delta $ = 0.50, Subramanian \textit{et al.} J. Solid State Chem. \textbf{72,} 24 (1988)].