Method of Distinguishing SrBi₂Ta₂O₉ Phase from Fluorite Phase Using X-Ray Diffraction Reciprocal Space Mapping

Abstract

In the Sr–Bi–Ta–Nb–O system, three crystallographic phases are known to exist: the SrBi2(Ta1-x Nb x )O9 (SBTN) perovskite, fluorite and pyrochlore phases. It is considered that the fluorite phase is a low-temperature phase of SBT, which tends to grow in excess bismuth compositions, and the pyrochlore phase tends to grow in bismuth-deficient compositions. In conventional X-ray diffraction (XRD) characterization, the SBTN phase shows strong (115) diffraction around 29 [2θ deg]. Unfortunately, however, the other two phases also show their (111) and (222) diffractions near the same angle when the film is prepared on a platinum-coated silicon substrate. Therefore, the phase identification of the SBTN phase from the other two phases is almost impossible by the conventional technique. We employed XRD reciprocal space mapping to distinguish these phases in the present study. The three crystallographic phases were identified and distinguished from each other. It is ascertained that this technique is effective to identify crystallographic phases especially in the case in which more than two phases show similar diffraction angles.

MOCVD of Single‐Axis c‐Oriented Strontium Bismuth Titanate Thin Films and Their Electrical Properties

“…[11] To identify the more detailed constituent phase and the orientation of the deposited films, a X-ray reciprocal space mapping method was used. [12] This mapping method is recognized as being useful for the present purpose, [13,14] and can analyze the orientation not only along the surface normal, but also along other directions, such as the in-plane orientation. Figure 3a correspond to a purely (001)-oriented SBTi phase, and this was also ascertained in Figure 3d by the method outlined below.…”

“…The constituent phase and the orientation of the films were identified by a XRD h-2h scan and the reciprocal space mapping (PANalytical X'pert-MRD) using Cu Ka radiation. The details of the mapping are reported elsewhere [12]. The surface morphology and the microstructure were observed by AFM operated in contact mode, and TEM.…”

Depth Profiling of Hydrogen and Oxygen in Ferroelectric Films Using High-Energy Ion Beam

“…perovskite phase. On the other hand, the diffraction pattern for the MOCVDgrown sample shows only several diffuse peaks that are difficult to identify unambiguously [11]. The strong peak around 29 • may represent the fluorite (111) [12], the Bi-deficient pyrochlore (222) [13], or perovskite-type [14] (008) and (115).…”

Ba(Zr Ti1−)O3 thin films for tunable microwave applications

“…For the XRD 2θ-Ψ area mappings of the BZT thin films, the angular ranges of measurement were 2θ¼ 20.0-50.0 for the 2θ-θ scan and 0 to 70.0 degree for the Ψ angle. It is possible to identify the crystal orientation and crystallographic phase of the films from these spots [39]. We can observe the diffraction spots of (100), (110), (111) and (200) for the (001)/(100)-oriented BZT films from the figures.…”