Dielectric Properties of Titanates Containg Sn4+Ions I

Abstract

Dielectric and thermal properties and lattice constants of the solid solutions of Pb(Ti·Sn)O 3 and Ba(Ti·Sn)O 3 were investigated, for the purpose of making clear the role of Y ion in the compounds of the perovskite type, XYO 3 . In Pb(Ti·Sn)O 3 , according to the X-ray analysis, two phases seem to co-exist in the samples containing Sn 4+ ions more than 75%, although the whole range solid solution might be expected from the standpoint of the “tolerance factor”. The Curie point moves to the low temperature side with the increase of the content of PbSnO 3 and reaches 200°C in Pb(20%Ti·80%Sn)O 3 . In Ba(Ti·Sn)O 3 , a rather steep decrease of the Curie temperature with the content of Sn 4+ ions occurs and the whole range solid solution seems to be realized, although the X-ray analysis was not thoroughly made in this case. The dielectric constant D ∼ E hysteresis loop, thermal expansion and specific heat were observed. An anomalous hysteresis phenomenon was observed in Pb(25%Ti·75%Sn)O 3 , which suggests that Ti 4+ Ion and Sn 4+ Ion respond differently to the external field in the ferroelectric state. Several speculations were mentioned with respect to this phenomenon.