phase needs to be used carefully as it is conceivable that the
two types of order can coexist on shorter length scales than
would be required to provide two XRD (or neutron diffraction)
distinguishable phases.
Both protonic and carbonate defects are present in BCT18,
although their crystallographic sites could not be determined
by diffraction methods. Both defects could be very relevant in
electrochemical or catalytic applications, such as intermediate
temperature fuel cells and CO2 separation membranes.
Thermal analysis and 1H NMR confirm that this material
contains structural protons with some structural mobility
at room temperature. Conductivity tests show that grain
conductivity is similar to BCN18; however, the data are
dominated by intergrain resistances due to poor sinterability
and so the relationship between bulk conductivity and relative
proportion of the ordered phases has not been probed.