The luminescent properties of two families of heteronuclear lanthanide-containing coordination polymers are compared. These families have general chemical formulas [Ln2-2xLn'2x(ip)3(H2O)9·6H2O]∞ and [Ln2-2xLn'2x(aip)2(H2O)10·(aip)·4H2O]∞ where H2ip and H2aip stand for isophthalic acid and 5-amino-isophthalic acid, respectively, and where Ln and Ln' are one of the lanthanide ions between Sm(3+) and Dy(3+). Heteronuclear compounds that belong to each family are isostructural to the already reported homonuclear compounds [Gd2(ip)3(H2O)9·6H2O]∞ and [Eu2(aip)2(H2O)10·(aip)·4H2O]∞, respectively. These two crystal structures are very similar. However, despite similar chemical formulas, similar crystal structures, and similar hydration rates, these two families of compounds present very different luminescent properties that have thus been deeply investigated. This study demonstrates that these different optical behaviors can be attributed to the presence of a PET (photoinduced electron transfer) mechanism that is only present in the amino-isophthalate-containing coordination polymers.

From the liquid state to room temperature, two successive solid-state phase transitions occur in pure zirconia. It is well-known that the last one (tetragonal to monoclinic) is martensitic and induces large volume variations and shear strains. Elastic and inelastic behaviors of zirconia-based materials are strongly influenced by this transition and the associated strain fields that it induces. Knowledge of strain and stress at the crystal scale is thus a crucial point. Using fully dense pure zirconia polycrystals obtained by a fuse casting process, we have determined at a sub-micrometric scale, by X-ray Laue microdiffraction, the strains map at room temperature in as-cast specimens and after a post elaboration high temperature thermal treatment. We observed that the fluctuation of deviatoric elastic strain is huge, the standard deviation of normal component being in the range of 1-2%. The heat treatment tends to even further increase this range of fluctuation, despite the development of a multiscale crack network formed during the cooling. Correspondingly, the associated stress level is also huge. It lies in the 5 GPa range with stress gradient amounting 1 GPa μm − 1 .