Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9784067 | Materials Science and Engineering: B | 2005 | 4 Pages |
Abstract
Phase transitions and dielectric properties of the (1 â x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 crystals with x = 0.3-0.5 are studied. The solid solutions in this composition range are shown to be relaxor ferroelectrics. The crystals with low x demonstrate a diffused maximum in the temperature dependences of the dielectric permittivity at Tm. Tm varies with frequency according to the Vogel-Fulcher law. The polarizing microscopy investigations reveal a first-order phase transition from the relaxor phase to the low-temperature ferroelectric phase at TC, which is several degrees below Tm. The permittivity peak in the crystals with x = 0.5 is sharp, and Tm is equal to TC and does not depend on frequency, as is typical of the transition from a ferroelectric to an ordinary paraelectric phase. Nevertheless, the relaxor, but not the paraelectric, phase is observed at T > Tm. This conclusion is confirmed by the observation of the temperature behaviour of complex dielectric permittivity at T > Tm, which is typical of relaxors and related to the existence of polar nanodomains.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
A.A. Bokov, H. Luo, Z.-G. Ye,