Influence of SiO
2 addition on formation process of Pb(Ti⋅Zr)O
3 solid solution was studied. Powdered PbO, TiO
2, ZrO
2 and SiO
2 were used as raw materials. The process was determined from the variation of X-ray diffraction patterns and that of dilatometric dimensional change with heating temperatures.
If the materials excluding SiO
2 were mixed, Pb(Ti⋅Zr)O
3 was synthesized, passing through formations both of PbTiO
3 and PbZrO
3. However, when the materials including SiO
2 were mixed, the PbZrO
3 formation was suppressed, accompanying by a decrease of Pb(Ti⋅Zr)O
3 formation temperature.
The difference seems to be caused by the appearance of a liquid phase formed by the co-existence of SiO
2 and PbO, which occurs during the Pb(Ti⋅Zr)O
3 formation process. Reaction observed at the contact surface of two green compacts, consisting of SiO
2-PbO as well as of Pb(Ti⋅Zr)O
3, was in line with the assumption.
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