Electric field induced splitting of the preferred orientation in PMN‐PT textured ceramics

Abstract

We have performed studies of the orientation distribution in <001>C textured, 0.03(Na1/2Bi1/2)TiO3 ‐ 0.97[0.715Pb(Mg1/3Nb2/3)TiO3 ‐ 0.285PbTiO3] (0.03NBT‐0.97[PMN‐28.5PT]) ceramics by a pole figure method, comparing the results to those for PMN‐PT single crystal and polycrystal samples. The pole figures about the (001) zone are found to have monoclinic, Ma, phase for textured ceramics in the annealed condition and were similar to those for electrically poled single crystals. However, electrical poling of the textured ceramics resulted in a doublet splitting of the orientation distribution about the direction that defined the original grain texturing. Studies of pole figures about other high‐symmetry zones also revealed the development of some degree of preferred orientation along the in‐plane directions after poling. Our findings demonstrate that E‐field induced phase transformation and domain textures superimpose with that of preferred grain orientations, giving rise to a unique texture symmetry for PMN‐PT. The texture symmetry changes are driven by minimization of the elastic strain energy, and have an important effect upon the piezoelectric properties.

Grain-Oriented Ferroelectric Ceramics with Single-Crystal-like Piezoelectric Properties and Low Texture Temperature

“…Therefore, the texture temperature of PYN-PMN-PT ceramics was reduced by at least 225 °C. Besides, the texture temperature to achieve high F 001 here is much lower than those reported previously on textured ceramics including both lead-based and lead-free ones, − ,− ,− ,, which can accelerate the application of relaxor-PT textured ceramics to multilayer electronic devices to cofire with inexpensive low-melting-point electrodes such as Ag-alloys and Cu.…”

“…The black lines I, II, and III in (c) indicate the plots of d 33 × g 33 = 20.0 × 10 –12 , 40.0 × 10 –12 , and 60.0 × 10 –12 m 2 N –1 , respectively. Note that the data for recently reported piezoelectric ceramics are obtained from the refs , , − , − , , .…”

“…The TGG process allows for very effective compositional control because such growth retains the chemical homogeneity of the greenbody . A series of relaxor-PbTiO 3 textured ceramics have been developed by TGG in recent years, such as Pb­(Mg 1/3 Nb 2/3 )­O 3 -PbTiO 3 (PMN-PT), Pb­(In 1/2 Nb 1/2 )­O 3 -Pb­(Mg 1/3 Nb 2/3 )­O 3 -PbTiO 3 (PIN-PMN-PT), and Pb­(Ni 1/3 Nb 2/3 )­O 3 -PbZrO 3 -PbTiO 3 (PNN-PZT). − Several approaches have been conducted to improve F 001 of these textured ceramics to be above 90%, such as controlling template type and concentration, doping texture aids, and optimizing thermal parameters. Consequently, remarkably enhanced piezoelectric properties (e.g., ∼20–120% higher electrostrain S max / E max , ∼20–170% higher piezoelectric charge coefficient d 33 , and ∼40–120% higher piezoelectric voltage coefficient g 33 ) have been achieved as compared to the nontextured ceramic counterparts, benefiting from the strong piezoelectric property of anisotropy and facilitating polarization rotation owing to the favorable engineered domain status in these textured ceramics. − …”

“…The first challenge is that a substantial performance gap still exists between high- F 001 relaxor-PbTiO 3 textured ceramics and single crystals in terms of piezoelectric properties, − which seriously hinders applications of textured ceramics in high-performance electronic devices. For example, electrostrain S max / E max and piezoelectric figure of merit d 33 × g 33 values of the extensively studied PMN-PT textured ceramics generally reach ∼40–70% and ∼35–60%, respectively, of the corresponding single-crystal responses, and their k 33 values only fall about halfway between nontextured ceramics and single crystals. − ,,− The second challenge is that high texture temperatures are generally needed for relaxor-PbTiO 3 ceramics to achieve high F 001 and thus enhanced piezoelectric properties relative to nontextured ceramics, − which makes them impossible to be cofired with cheap low-melting-point (<1000 °C) inner electrodes, inhibiting their applications in multilayer electronic devices for miniaturization and integration. For example, 1250 °C-textured 0.155Pb­(Yb 1/2 Nb 1/2 )­O 3 -0.465Pb­(Mg 1/3 Nb 2/3 )­O 3 -0.38PbTiO 3 ceramics possessed F 001 ∼ 91% and 45% higher S max / E max value (∼725 pm V –1 at 40 kV cm –1 ), while the 1000 °C-textured samples showed F 001 ∼ 53% and very low S max / E max ∼ 400 pm V –1 .…”

“…We chose 0.16Pb­(Yb 1/2 Nb 1/2 )­O 3 -0.52Pb­(Mg 1/3 Nb 2/3 )­O 3 -0.32PbTiO 3 as an example because it has a rhombohedral structure near the MPB and possesses a relatively high Curie temperature T c ∼ 200 °C, which enables the formation of a “4R” engineered multidomain configuration to further enhance piezoelectric response in textured ceramics and also provides a wide temperature usage range for device applications. [001] c -textured ceramics with F 001 as high as ∼99% were successfully synthesized at only 975 °C through a liquid-phase-assisted TGG process, from which single-crystal piezoelectric properties, i.e., very large S max / E max ∼ 1830 pm V –1 (at 20 kV cm –1 ), giant d 33 × g 33 ∼ 61.3 × 10 –12 m 2 N –1 , and high k 33 ∼ 0.90, were achieved, representing the highest values ever reported in piezoelectric ceramics. ,,− Grain orientation features were quantitatively compared between the regularly 1200 °C-textured and low-temperature textured ceramics, and phase-field simulations were conducted to provide fundamental insights into how orientation features affect the piezoelectric response. To understand microscopic origin(s) for the single-crystal performance achieved, relationships among texture evolution, phase structure, microstructure, grain orientation features, domain characteristics, and piezoelectric properties were systematically investigated.…”