Ferroelectric properties of ruthenium-doped lead zinc niobate-lead titanate single crystal

Abstract

Using atomic force microscopy and piezoresponse force microscopy (PFM), as well as complementary dielectric measurements, the ferroelectric domain structure of single crystals of pure and ruthenium (Ru)-doped 0.9Pb(Zn1/3Nb2/3)O3 (PZN)-0.1PbTiO3 (PT), and Ru/(Zn+Nb+Ti)∼0.002 was analyzed. The coexistence of tetragonal and nontetragonal ferroelectric domains in PZN-PT near the morphotropic phase boundary (MPB) was directly observed via PFM imaging. The incorporation of Ru in the perovskite structure substantially decreases the ferroelectric domain size, thus reducing the polar fraction distributed in the pseudocubic matrix. The polarization and strain hysteresis loops show that Ru doping leads to significant ferroelectric hardening, which is attractive for high-power applications. The local structure and valent state of the incorporated Ru cations were additionally analyzed by electron paramagnetic resonance spectroscopy. Our results demonstrate that doping of tetragonal PZN-PT near MPB is a promising route to design advanced multifunctional single-crystal materials.

X-ray absorption spectroscopy of Ru-doped relaxor ferroelectrics with a perovskite-type structure

“…The XANES results on PZN-01.PT-Ru indicate that the majority of Ru has an oxidation state of 4, with a minor content of Ru that has an average oxidation state lower than 4. This is in good accordance with a previous electron paramagnetic resonance analysis of PZN-0.1PT-Ru [15] revealing the existence of paramagnetic Ru 3+ and Ru 5+ centers, with the fraction of Ru 3+ being larger than the fraction of Ru 5+ at room temperature.…”

“…In addition, Ru-containing perovskites exhibit nontrivial magnetic properties [12][13][14], which might be related to the multivalent state of Ru. Recently, piezoresponse force microscopy and hysteresis loop measurements of 0.9PbZn 1/3 Nb 2/3 O 3 -0.1PbTiO 3 (PZN-0.1PT), which is a relaxor-ferroelectric solid solution with a giant piezoelectric effect [8], revealed that the addition of Ru decreases the ferroelectric domain size, reduces the polar fraction distributed in the pseudocubic matrix, and leads to significant ferroelectric hardening due to the immobilization of domain walls [15]. Hence, the incorporation of Ru into relaxor-ferroelectric host matrices has the potential to induce new properties and thus to improve the multifunctionality of the material, which in turn is a strong motivation for fundamental structural studies of Ru-doped relaxor ferroelectrics.…”

Pressure-induced structural transformations in pure and Ru-doped 0.9PbZn1/3Nb2/3OWaeselmann1, Maier2, Mihailova3 et al. 2012Phys. Rev. BSelf Cite

“…At ambient pressure, the addition even of a small amount of Ru (Ru/(Zn+Nb+Ti) ~ 0.002) leads to a substantial hardening of the polarization-field and strain-field hysteresis loops of PZN-0.1PT 7 and favors the tetragonal state in a wider temperature range compared to the undoped compound. 12 These effects are attributed to the fact that Ru substitutes for Ti and at room temperature the average valence of the ruthenium cations is between 4+ and 3+.…”

Atomic-scale evolution of modulated phases at the ferroelectric–antiferroelectric morphotropic phase boundary controlled by flexoelectric interaction

“…Each one of these theories explains a subset of macroscopic and microscopic observations of these systems, but the ultimate validity test should be that they reproduce the order-parameter field behaviour as observed on the local (atomic) level. Until recently, spatially resolved studies were limited to direct mesoscopic imaging of the nanophase domains [13][14][15][16] , or nanodiffraction experiments in transmission electron microscopes 17 . Such methods provide information on symmetry and misorientation of the nanodomains with respect to each other.…”