TITLE:
Mn Effect on Nonlinear and Structural Properties of Oriented PZN-4.5PT Single Crystals
AUTHORS:
Diouma Kobor, Modou Tine, Abdelowahed Hajjaji, Laurent Lebrun, Daniel Guyomar
KEYWORDS:
XRD; Dielectric; Piezoelectric; EPR; Raman; Spectroscopy
JOURNAL NAME:
Journal of Modern Physics,
Vol.3 No.5,
May
23,
2012
ABSTRACT: Ferroelectric single crystals Pb(Zn1/3Nb2/3)O3-PbTiO3 (PZN-PT) are promising full materials for non resonant or large bandwidth transducers due to the large values of their piezoelectric properties (d ij , k ij ) and their low mechanical quality factor (Q ij ). Many studies on oriented PZN-4.5PT single crystals were carried out but it is very difficult to find research findings on oriented Mn doped PZN-PT. Thus, investigations were made using XRD, Raman and EPR characterization for oriented PZN-4.5PT grown through the Flux method. Mn doping effect on structural, dielectric, mechanical and piezoelectric properties with two values of Mn percentage (1 and 2 mol%) are also reported in this paper. Through the XRD study, the lattice parameters of doped PZN-PT crystals are slightly increased compared to the undoped one but the Mn didn’t change its structure. The room temperature dielectric permittivity along direction is about 1572 and 1626 (respectively 1% and 2% Mn doped crystals) which are much lower than that of the undoped PZN-4.5PT (2553). The remnant polarization and coercive field of oriented doped crystal measured at 1 KHz are respectively 30 μC/cm2 and 4.30 kV/cm (PZN-4.5PT), 32 μC/cm2 and 6.10 kV/cm (PZN-4.5PT + 1% Mn) and 28 μC/cm2 and 7.30 kV/cm (for the 2% Mn doped crystal). The mechanical quality factor Qm changed from 139 to 441 respectively for the pure and 1% Mn doped single crystals at room temperature while it decreases slightly to 336 for the 2 mol% Mn doped.