Raman Spectroscopic Determination of Pyrochlore-Type Compound on the Synthesis and Decomposition of Sol-Gel-Derived Pb(Mg1/3Nb2/3)O3(PMN)

Phase evolution of lead titanate from its amorphous precursor synthesized by the OPM wet-chemical route

“…However, the general shape of the spectrum of Fig. 2b is similar to that observed for the pyrochlore lead pyroniobate (Pb 2 Nb 2 O 7 ), with main peaks at 145, 231, 285, 334, and 741 cm À1 , [20][21][22] indicating that some correspondence between these two structures (Pb 2 Nb 2 O 7 and the stoichiometric Pb 2 Ti 2 O 6 ) can be considered. [20] The spectrum of Fig.…”

Combined wet-chemical process to synthesize 65PMN-35PT nanosized powders

“…Spectra of the powders calcined at 700 and 800 • C shows only one peak, centered at approx. 785 cm −1 , typical of the perovskite phase [13]. On the other hand, it is evident the presence of more than one peak in the spectra of the powders calcined at 900 and 950 • C, what can be interpreted as the presence of the cubic Pb 1,86 Mg 0.24 Nb 1.76 O 6.5 pyrochlore phase.…”

“…5b) shows a more complex structure, with bands at 711 and 785 cm −1 , which can be assigned as the A 1g modes of the PMN-PT as discussed previously, and two additional bands at 742 and 799 cm −1 . It is rather difficult to distinguish precisely by XRD the Pb 1,86 Mg 0.24 Nb 1.76 O 6.5 pyrochlore from another pyrochlore-type structure without magnesium in their composition, however Wakiya et al [13] assigned two bands at 745 and 815 cm −1 undoubtedly to the Pb 1,86 Mg 0.24 Nb 1.76 O 6.5 pyrochlore phase. The analysis of the spectrum of the powder calcined at 900 • C shows similar result, therefore, it is possible to assign these additional bands in the Fig.…”

Study of microstructure and dielectric properties of PMN–PZT ceramics via a mixed powder method including sol–gel precursor

“…activation [7,8] or sol-gel [9][10][11] methods. Synthesis of single phase PMN requires more specified processing routes, such as columbite route [12][13][14][15], mechanical activation process [16][17][18], reaction sintering process [19][20][21] and sol-gel method [22,23]. There are also more routes proposed by other authors for PMN-PZT production such as mixed oxide method [24], columbite or corundum routes [25] and wet chemical routes [26,27].…”