0000000000377076
AUTHOR
Brahim Elouadi
Crystal chemistry and phase transitions in mixed niobates crystallizing with tetragonal tungsten bronze structure
Abstract New compounds crystallizing with tungsten bronze structure are reported. A dielectric study and X-ray analysis at various temperatures have allowed to describe some phase transitions.
Crystal chemical and dielectric properties of Pb0.5(5-x)LaxNb5-xFexO15system with “tetragonal tungsten bronze” structural type
The lanthanum-lead and iron-niobium coupled substitution in PbNb 2 O 6 have allowed to isolate new materials of a general formula Pb 0.5(5-x) La x Nb 5-x Fe x O 15 crystallising with the tetragonal tungsten bronze structural type. The resulting influence on the lattice parameters, the ferroelectric Curie temperature and Cole - Cole plots are presented. A typical ferroelectric - paraelectric behaviour occurs in the composition range 0 ≤ x ≤ 0.33 while, a relaxor behaviour is observed in the composition range 0.33 < x < 1.