Study of the 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 preliminary 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. This system has been found to have excellent reversible OSC at low-temperatures of 200 - 375\r{ }C and oxygen content of these structures have also been found to be sensitive to changes of partial-pressures of oxygen in this low-temperature range, 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 transition between hexagonal P6$_{3}$cm ($\delta $ = 0) and a previously unreported phase of this system ($\delta $ = 0.25, currently under investigation) and pyrochlore Fd3m ($\delta $ = 0.50, Subramanian et al. J. Solid State Chem. 72 (1988) 24).