Author(s)

Diouma Kobor, Modou Tine, Abdelowahed Hajjaji, Laurent Lebrun, Daniel Guyomar

Ecole Nationale des Sciences Appliquées d’El Jadida.
Laboratoire de Chimie et de Physique des Matériaux (LCPM), Département de Physique, Université de Ziguinchor.
Laboratoire Génie Electrique et Ferroélectricité, Institut National des Sciences Appliquées de Lyon.

Ferroelectric single crystals Pb(Zn_1/3Nb_2/3)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 <001> oriented PZN-4.5PT single crystals were carried out but it is very difficult to find research findings on <110> oriented Mn doped PZN-PT. Thus, investigations were made using XRD, Raman and EPR characterization for <110> 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 <110> 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 <110> 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 Q_m 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.

XRD; Dielectric; Piezoelectric; EPR; Raman; Spectroscopy

D. Kobor, M. Tine, A. Hajjaji, L. Lebrun and D. Guyomar, "Mn Effect on Nonlinear and Structural Properties of <110> Oriented PZN-4.5PT Single Crystals," Journal of Modern Physics, Vol. 3 No. 5, 2012, pp. 404-411. doi: 10.4236/jmp.2012.35056.