Dielectric, electric and Raman studies on the RbK(SO4)·Te(OH)6 material

N. Chabchoub (1) , Hamadi Khemakhem (1) , Régnault von Der Mühll (2)

1 LPA - Laboratoire de Physique Appliquée [Université de Sfax]
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Single crystals of RbK(SO4)·Te(OH)6 are obtained by slow evaporation at room temperature. The frequency and temperature dependencies of the real part of the permittivity, r′, show that this material presents three phase transitions at T1 = 490 K, T2 = 535 K and T3 = 580 K. DSC measurements on RbK(SO4)·Te(OH)6 have been carried out in the temperature ranges 350–650 K. It reveal three endothermic peaks at around T1, T2 and T3. Complex impedance measurements are performed on this material at various temperatures. A substantial jump of the conductivity, attributed to the motion of H+, is observed at high temperatures. This behavior indicates the presence of superprotonic phase transition in RbK(SO4)·Te(OH)6. Raman spectra of RbK(SO4)·Te(OH)6, recorded at various temperatures (300–550 K) in the frequency range 200–1200 cm−1, confirm the presence of the phase transitions and especially the ferroelectric and the superprotonic phase transition.

Mots clés: Ferroelectric phase; Paraelectric phase; Superionic conduction; Raman spectra

Domaines: Matériaux

N. Chabchoub, Hamadi Khemakhem, Régnault von Der Mühll. Dielectric, electric and Raman studies on the RbK(SO4)·Te(OH)6 material. Journal of Alloys and Compounds, 2005, 386, n° 1-2, p. 319-325. ⟨10.1016/j.jallcom.2004.06.018⟩. ⟨hal-00022176⟩