کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1290991 | 973346 | 2007 | 7 صفحه PDF | دانلود رایگان |
Ferroelastic domains, Raman scattering, XRD and DSC studies of [(NH4)0.14Rb0.86]3H(SO4)2 and [(NH4)0.1Rb0.9]3H(SO4)2 mixed crystals are presented. Two endothermic peaks were found for both crystals in DSC heating runs at TS and T′ST′S. A difference T′S−TST′S−TS decreases with increasing Rb content. It was confirmed from X-ray diffraction studies that at TS the crystal structure changes from C2/c to R3¯m. At T′ST′S the crystals undergo a successive structural transition to the phase which could be characterized by three dimensional system of virtual hydrogen bonds and a new type of virtual dimers. Our provisional XRD studies showed that the crystal structure at T>T′ST>T′S may belongs to orthorhombic system. In Raman studies it was found that at T′ST′S the Raman spectra of [(NH4)0.1Rb0.9]3H(SO4)2 undergo conspicuous changes. All our studies revealed that the crystals become polycrystalline at T′ST′S, and temperature lowering results in a huge thermal hysteresis. It is presumed that structural relaxation exists in the crystals.
Journal: Journal of Power Sources - Volume 173, Issue 2, 15 November 2007, Pages 688–694