X-ray diffraction, thermal analysis, and Raman scattering study of K2BeF4 and comparation to other member of the (beta)-K2SO4 family with ferroelectric -paraelectric transition

Solans, Xavier, 1949-2007González-Silgo, CristinaCalvet Pallàs, Maria TeresaRuiz-Pérez, C.Martínez Sarrión, María LuisaMestres i Vila, Ma. Lourdes2009-12-292009-12-2919980163-1829https://hdl.handle.net/2445/10637Thermal analysis, powder diffraction, and Raman scattering as a function of the temperature were carried out on K2BeF4. Moreover, the crystal structure was determined at 293 K from powder diffraction. The compound shows a transition from Pna21 to Pnam space group at 921 K with a transition enthalpy of 5 kJ/mol. The transition is assumed to be first order because the compound shows metastability. Structurally and spectroscopically the transition is similar to those observed in (NH4)2SO4, which suggests that the low-temperature phase is ferroelectric. In order to confirm it, the spontaneous polarization has been computed using an ionic model.4 p.application/pdfeng(c) The American Physical Society, 1998DifraccióFerroelectricitatDielèctricsDiffractionFerroelectricityDielectricsX-ray diffraction, thermal analysis, and Raman scattering study of K2BeF4 and comparation to other member of the (beta)-K2SO4 family with ferroelectric -paraelectric transitioninfo:eu-repo/semantics/article118217info:eu-repo/semantics/openAccess