Anti-ferrodistortive Nanodomains in PMN Relaxor
نویسندگان
چکیده
Temperature dependent studies of the 1/2(hk0) superlattice reflections (α spots) by synchrotron x-ray scattering measurements were performed in Pb(Mg1/3Nb2/3)O3 (PMN) and [PbMg1/3Nb2/3O3]1−x− [PbTiO3]x (PMN-xPT) with Ti doping x≤ 0.32 single crystals. Separation of the α spots from the underlying diffuse scattering background allowed studying them as separate entities for the first time. Structure factor calculations have shown that α spots constitute the presence of a new kind of anti-ferrodistortive nanoregions (AFR) in the form of fluctuations produced by anti-parallel short-range correlated 〈110〉 Pb2+ displacements. AFR appear to be different and unrelated to the chemical nanodomains (CND) and ferroelectric polar nanoregions (PNR). Simultaneous presence of AFR and PNR can explain relaxor behavior as a result of competition between randomly occurring ferroelectric and anti-ferroelectric fluctuations. Temperature dependence of the α spots in PMN showed a direct correlation with the freezing phase transition near T f≈220 K.
منابع مشابه
Synchrotron X-ray Studies of Superlattice Ordering in Pb(Mgi/3Nb2/3)O3 Single Crystals Doped with PbTiO3
The temperature dependence of the superlattice reflections: a) F spots and b) a spots in a lead magnesium niobate (PMN) single crystals containing 0% and 6% of PbTiO3 (PT) has been studied using synchrotron x-ray scattering techniques. (No superlattice reflections were found in PMN doped with 32% PT). Analysis of the temperature dependence of the a spots suggests the existence of the correlated...
متن کاملDomain Growth in Pb(Mg1/3Ta2/3)O3 Perovskite Relaxor Ferroelectric Oxides
Extensive studies that have been conducted on the Pb(Mg1/3Nb2/3)O3 (PMN) family of relaxor ferroelectrics have led to the establishment and acceptance of the ‘‘spacecharge’’ model as a basis for explaining their structures and dielectric properties. In this model, the arrangement of the metal cations on the octahedral sites of the perovskite structure is interpreted in terms of the formation of...
متن کاملEvolution of nanodomains during the electric-field-induced relaxor to normal ferroelectric phase transition in a Sc-doped Pb(Mg1/3Nb2/3)O3 ceramic
Sc doping in Pb(Mg1/3Nb2/3)O3 enhances the B-site 1:1 cation order significantly but promotes the ferroelectric polar order moderately. At low doping levels, the electrical polar domains remain at the nanometer scale and the relaxor ferroelectric behavior is preserved. A normal ferroelectric state can be triggered with electric fields from the relaxor state at lower temperatures. This electric-...
متن کاملBZT: A Soft Pseudospin Glass.
In an attempt to understand the origin of relaxor ferroelectricity, it is shown that interesting behavior of the onset of nonergodicity and of precursor nanodomains, found in first-principles simulations of the relaxor alloy Ba(Zr(1-x)Ti(x))O(3), can easily be understood within a simple mapping to a soft pseudospin glass.
متن کاملHigh Performance Relaxor-Based Ferroelectric Single Crystals for Ultrasonic Transducer Applications
Relaxor-based ferroelectric single crystals Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) have drawn much attention in the ferroelectric field because of their excellent piezoelectric properties and high electromechanical coupling coefficients (d33~2000 pC/N, kt~60%) near the morphotropic phase boundary (MPB). Ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystals also possess outstan...
متن کامل