Anomalous step at xequals, falling dots0.7 in potential−composition profiles of LixCryMn2−yO4 spinels at low temperature

In order to investigate the relation between spinel type structure and anomaly in potential–composition profile of stoichiometric LiMn2O4 spinel at low temperature (T≤278 K), several LiCryMn2−yO4 type spinels (y=0.01–0.25) have been synthesized by conventional solid-state reaction and their potential–composition (φ–x; LixCryMn2−yO4) profiles at 273 K have been recorded. The φ–x profiles of the specimens (y=0.01–0.03) show an anomalous stepwise feature as one that stoichiometric LiMn2O4 shows at low temperature. However, the step at xequals, falling dots0.7 becomes weak with increase of the value y, and finally disappears. In the specimens, Mn and Cr are considered to occupy only 16d sites of spinel type structure. As compared with the φ–x profiles of lithium-excess type spinels Li1+δMn2−δO4 and lithium-deficient type spinels Li1−δMn2O4, the gradual result suggests that state of Mn lattice strongly affects the appearance of anomalous step at xequals, falling dots0.7.