We report a metal-organic material of the following formula [dabcoH22+]·CrCl3(H2O)3·2(Cl-) (dabcoH22+ = C6H14N22+, diprotonated 1,4-diazabicyclo[2.2.2]octanium). This compound exhibits a dielectric anomaly, attributed to the rotatory fluctuation of the dabco molecule....

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Methods of introducing two ferroelectric materials, viz. NaNO 2 and (CH 3 NH 3 ) 5 Bi 2 Cl 11 (PMACB), into porous glass matrices and the results of dielectric, pyroelectric, thermal expansion and SEM investigations are presented. The best filling degree was achieved for NaNO 2 introduced from the melt, whereas a significantly worse filling effect was achieved for a water solution as the introducing agent. A splitting was observed in the temperature dependence of dielectric permittivity related to the incommensurate phase of NaNO 2 embedded in porous glass from a water solution, whereas no incommensurate phase was observed in the case of glass filled with NaNO 2 from the melt. The confined materials turned out to possess ferroelectric properties and exhibited phase transitions. The negative size effect was observed for porous glasses filled with NaNO 2 and PMACB. The above conclusions are based on the anomaly of dielectric, pyroelectric and dilatometric properties observed in the phase transition regions.