Dielectric properties of relaxor-ferroelectric ceramic and single crystal Pb(In${}_{1/2}$Nb${}_{1/2}$)O${}_3$-Pb(Mg${}_{1/3}$Nb${}_{2/3}$)O${}_3$-PbTiO${}_3$ at cryogenic temperatures

Abstract

We investigate the low temperature behaviour of Pb(In${}_{1/2}$Nb${}_{1/2}$)O${}_3$-Pb(Mg${}_{1/3}$Nb${}_{2/3}$)O${}_3$-PbTiO${}_3$ using dielectric permittivity measurements. We compare single crystal plates measured in the [001] and [111] directions with a polycrystalline ceramic of the same composition. Poled crystals behave very differently to unpoled crystals, whereas the dielectric spectrum of the ceramic changes very little on poling. A large, frequency dependent dielectric relaxation seen in the poled [001] crystal around 100 K is much less prominent in the [111] crystal, and doesn't occur in the ceramic. Preparation conditions and the microstructure of the material play a role in the low temperature dynamics of relaxor-ferroelectric crystals.

6 pages, 3 figures