Wydział Chemii

Jolanta Jóźków

Ryszard Jakubas

Grażyna Bator

Adam Pietraszko

2001

Journal of Chemical Physics

114

7239-7246

10.1063/1.1349897

Naukowa

Angielski

Artykuł

A new pyridinium compound, ( C5H5NH!5Bi2Br11, has been synthesized. The x-ray diffractionstudies indicate that its structure is built up of four independent pyridinium cations and isolatedBi2Br1152groups. At room temperature it crystallizes in the monoclinic space groupP21/n. Twophase transitions of second- and first-order type are detected by the differential scanning calorimetrymeasurements at 118 and 405/403 K~on heating–cooling!, respectively. The correspondinganomalies in the linear thermal expansion at 118 and 405 K are observed along threecrystallographic directions. The dielectric investigations reveal dielectric absorption and dispersionin the radio-frequency region. The experimental results were analyzed on the basis of dielectricformula which represents the sum of two independent relaxators. The pyroelectric measurementsreveal that ( C5H5NH!5Bi2Br11becomes ferroelectric below 118 K and is characterized by theappearance of spontaneous polarization of the order of 3ï1023C/m2along thebaxis.

https://doi.org/10.1063/1.1349897

https://www.aip.org/