Defect-Chemistry of the System Pr1-xCaxMnO3
4. August 2022
The formation of vacant oxygen sites in PCMO determined by thermogravimetry and DC-conductivity as a function of oxygen partial pressure p(O2) relates to the presence of the mixed valence states of tri- or tetravalent Mn-cations. Electrical transport properties relevant for ReRAM-applications depend on the mobility of free charge carrier, which is drastically reduced when the number of oxygen vacancies increases to a deficiency exceeding 1000 ppm.
Detailed crystallographic studies based on refined neutron-diffraction experiments for reduced ceramic material suggest, that the reduction in electron transfer rates between tri- and tetravalent cations of manganese originates from an anisotropy effect. For the case of comparatively large oxygen deficiency, vacancies preferentially form on lattice sites in the equatorial plane of MnO6-octahedra rather than on their apices.
"Oxygen Non-Stoichiometry and Electrical Transport Properties of Pr1-xCaxMnO3 Ceramics." C. Pithan, Y. Iida, J. Dornseiffer, A. Tsubouchi, R. Waser; J. Eur. Ceram. Soc. (2022) https://doi.org/10.1016/j.jeurceramsoc.2022.08.006
Last Modified: 20.02.2025