Structural Phase Transitions between 700 and 850.DEG.C. in SrZrO3 Studied by Raman Spectroscopy

Abstract

12) The tilting is described using the symbols a, in which the three letters abc, respectively, refer to the magni tudes of the tilts around the [100], [010], and [001] directions of the aristotype, and the superscript # takes the value 0, {, or | that indicate no tilt around an axis and tilts of successive octahedra in the same and opposite senses, respectively. Þ2 We use irreducible representations pertaining to the cubic phase, even though the phase we consider is not cubic, but pseudocubic. In our previous study of SrZrO 3 , 13) we noted that the sequence of condensation of soft modes from the hightemperature cubic phase is R 25 , M 3 , and finally R 25 again, on the basis of Ref. 7). Recently, however, Howard et al. 11) pointed out that the space group Cmcm previously proposed really corresponds to Imma. Thus we alter softmode condensation from the cubic phase.

Yb2O3‐Gd2O3 codoped strontium zirconate composite ceramics for potential thermal barrier coating applications

“…The second exothermic peak appears at approximately 850°C, corresponding to the phase transition of SZO from the pseudo‐tetragonal phase to the tetragonal. The transition type is first‐order close to second‐order . Taking into account the experimental accuracy and sample differences, our results are consistent with those reported in previous works .…”

Phase stability and shear softening inCaSiO3perovskite at high pressure

“…First, while I4/mcm to Imma transitions are common in perovskites, the higher temperature phase is invariably tetragonal. [45][46][47][48][49][50] Second, the thermal energy available to drive the transition appears to be too small to overcome the I4/mcm-Imma enthalpy difference. Whereas in Ref.…”

Investigation of structural phase transition behavior of SrZrO3 by thermal analyses and high-temperature X-ray diffraction

“…Kennedy et al [6] and Ahtee et al [7] carried out high-temperature neutron powder diffraction measurements of SrZrO 3 and reported its crystal structure and phase transitions. Kennedy [9,10]. They observed the variation in the Raman spectroscopy at 720°C, 830°C and 1200-1220°C.…”