Growth and Electric Properties of Al-Substituted Langasite-Type La3Ta0.5Ga5.5O14 Crystals at High Temperature

2006 ◽  
Vol 320 ◽  
pp. 239-242 ◽  
Author(s):  
Hiroaki Takeda ◽  
Satoshi Tanaka ◽  
Hiroyuki Shimizu ◽  
Takashi Nishida ◽  
Tadashi Shiosaki
Keyword(s):  
High Temperature ◽  
Single Crystals ◽  
Electromechanical Coupling ◽  
Solubility Limit ◽  
Electric Resistivity ◽  
Electric Properties ◽  
Czochralski Technique ◽  
Al Substitution ◽  
Coupling Factors ◽  
Lower Temperature

We report an effective substitution of aluminum for gallium in langasite-type La3Ta0.5Ga5.5O14 (LTG) crystals for use in a pressure sensor at high temperature. Al-substituted LTG (La3Ta0.5Ga5.5-xAlxO14; LTGAx) single crystals up to the solubility limit of x=0.5 have been grown by the conventional Czochralski technique. The electric properties of the LTGAx crystals were investigated and compared with those of LTG. By Al substitution, the piezoelectric constant d11 and the electromechanical coupling factors (k12) became slightly larger. The LTGAx crystals showed a lower temperature dependence of d11 and a higher electric resistivity ρ than those of the LTG crystals.

Crystal structures and high-temperature vibrational spectra for synthetic boron and aluminum doped hydrous coesite

2020 ◽  
Author(s):  
Yu Ye ◽  
Yunfan Miao ◽  
Joseph R. Smyth ◽  
Junfeng Zhang
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystals ◽  
Vibrational Spectra ◽  
Fourier Transformation ◽  
Ambient Pressure ◽  
Al Content ◽  
Al Substitution ◽  
Long Time

<p>Coesite, a high-pressure SiO2 polymorph, has drawn extensive interest from the mineralogical community for a long time. In this study, we synthesized hydrous coesite samples with different B and Al concentrations at 5 and 7.5 GPa (1273 K). The B concentration could be more than 400 B/10<sup>6</sup>Si with about 300 ppmw. H2O, while the Al content can be as much as 1200 ~ 1300 Al/10<sup>6</sup>Si with CH2O restrained to be less than 10 ppmw. Hence, B-substitution may prefer the mechanism of Si<sup>4+</sup> = B<sup>3+</sup> + H<sup>+</sup>, whereas Al-substitution could be dominated by 2Si<sup>4+</sup> = 2Al<sup>3+</sup> + O<sub>V</sub>. The doped B<sup>3+</sup> and Al<sup>3+</sup> cations may be concentrated in the Si1 and Si2 tetrahedra, respectively, and make noticeable changes in the Si-O4 and Si-O5 bond lengths. In-situ high-temperature Raman and Fourier Transformation Infrared (FTIR) spectra were collected at ambient pressure. The single crystals of coesite were observed to be stable up to 1500 K. The isobaric Grüneisen parameters (ϒ<sub>i<em>P</em></sub>) of the external modes (< 350 cm<sup>-1</sup>) are systematically smaller in the Al-doped samples, as compared with those for the Al-free ones, while most of the OH-stretching bands shift to higher frequencies in the high temperature range up to ~ 1100 K</p>

High-Performance Piezoelectric Single Crystals of Complex Perovskite Solid Solutions

MRS Bulletin ◽  
2009 ◽  
Vol 34 (4) ◽  
pp. 277-283 ◽  
Author(s):  
Zuo-Guang Ye
Keyword(s):  
Single Crystals ◽  
Solid Solutions ◽  
High Performance ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
High Strain ◽  
Complex Perovskite ◽  
Device Applications ◽  
Coupling Factors ◽  
Piezoelectric Performance

AbstractRelaxor-based single crystals of complex perovskite solid solutions, Pb(Mg1/3Nb2/3)O3–PbTiO3 [PMN–PT] and Pb(Zn1/3Nb2/3)O3–PbTiO3 [PZN–PT], exhibit extraordinary piezoelectric performance, with extremely high piezoelectric coefficients, very large electromechanical coupling factors, and exceptionally high strain levels. These materials outperform the currently used Pb(Zr1–xTix)O3 [PZT] ceramics, making them the materials of choice for the next generation of electromechanical transducers for a broad range of advanced applications. In this article, recent major advances in the development of piezocrystals are reviewed in terms of crystal growth, piezoelectric properties, crystal chemistry, domain structure, and device applications.

scholarly journals Crystal Structures and High-Temperature Vibrational Spectra for Synthetic Boron and Aluminum Doped Hydrous Coesite

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 642 ◽  
Author(s):  
Yunfan Miao ◽  
Youwei Pang ◽  
Yu Ye ◽  
Joseph R. Smyth ◽  
Junfeng Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystals ◽  
Vibrational Spectra ◽  
Fourier Transformation ◽  
Ambient Pressure ◽  
Al Content ◽  
Al Substitution ◽  
Long Time

Coesite, a high-pressure SiO2 polymorph, has drawn extensive interest from the mineralogical community for a long time. In this study, we synthesized hydrous coesite samples with different B and Al concentrations at 5 and 7.5 GPa (1273 K). The B concentration could be more than 400 B/106Si with about 300 ppmw H2O, while the Al content can be as much as 1200 to 1300 Al/106Si with CH2O restrained to be less than 10 ppmw. Hence, B-substitution may prefer the mechanism of Si4+ = B3+ + H+, whereas Al-substitution could be dominated by 2Si4+ = 2Al3+ + OV. The doped B3+ and Al3+ cations may be concentrated in the Si1 and Si2 tetrahedra, respectively, and make noticeable changes in the Si–O4 and Si–O5 bond lengths. In-situ high-temperature Raman and Fourier Transformation Infrared (FTIR) spectra were collected at ambient pressure. The single crystals of coesite were observed to be stable up to 1500 K. The isobaric Grüneisen parameters (γiP) of the external modes (<350 cm−1) are systematically smaller in the Al-doped samples, as compared with those for the Al-free ones, while most of the OH-stretching bands shift to higher frequencies in the high temperature range up to ~1100 K

scholarly journals Investigation of Electro-Elastic Properties for LN Single Crystals at Low Temperature

2021 ◽  
Vol 11 (16) ◽  
pp. 7374
Author(s):  
Feifei Chen ◽  
Chao Jiang ◽  
Fapeng Yu ◽  
Xiufeng Cheng ◽  
Xian Zhao
Keyword(s):  
Single Crystals ◽  
Elastic Properties ◽  
Electromechanical Coupling ◽  
Temperature Stability ◽  
Piezoelectric Response ◽  
Impedance Method ◽  
Shear Vibration ◽  
Temperature Dependences ◽  
Coupling Factors ◽  
Thickness Shear

Lithium niobate crystals (LiNbO3, LN) are multifunctional crystal materials with many outstanding properties. In this work, the electro-elastic properties of LN single crystals were explored at temperatures from −150 °C to 150 °C. The temperature dependences of dielectric permittivities, elastic compliances, electromechanical coupling factors and piezoelectric coefficients were determined using the impedance method. The LN crystals possessed large dielectric permittivities, the ε11T/ε0 and ε33T/ε0 were 83.2 and 29.4 at room temperature, respectively. The elastic compliances s11, s13, s33 and s44 presented a positive increase as the temperature increased, and the variations were 5.0%, 8.2%, 4.6% and 5.4%, respectively, showing a good temperature stability. Moreover, the temperature dependence of the electromechanical coupling factors and piezoelectric coefficients for different vibration modes were studied with a temperature range from −150 °C to 150 °C, where the thickness shear vibration mode d15 presented a large piezoelectric response and minimal temperature variation.

Electrical Properties of Grain-Oriented SrBi2Nb2-xVxO9 Ceramics

2006 ◽  
Vol 320 ◽  
pp. 31-34 ◽  
Author(s):  
Shinya Inai ◽  
Yuji Hiruma ◽  
Rintaro Aoyagi ◽  
Hajime Nagata ◽  
Tadashi Takenaka
Keyword(s):  
Electrical Properties ◽  
Low Temperature ◽  
Grain Orientation ◽  
Electromechanical Coupling ◽  
Hot Forging ◽  
Electric Properties ◽  
Orientation Effects ◽  
Temperature Dependences ◽  
Coupling Factors ◽  
Piezoelectric Constants

Vanadium-substituted strontium bismuth niobate, SrBi2Nb2-xVxO9 (SBNVx), ceramics were synthesized by a low-temperature ceramic fabrication process; their electric properties were characterized, and grain orientation effects on their electric properties were also investigated using a hot-forging (HF) method. Resonance characteristics of the (33) and (15) modes of grain-oriented SBNV0.1 (HF) showed relatively high electromechanical coupling factors of k33=0.272 and k15=0.151 as well as piezoelectric constants of d33=31.7 pC/N and d15=24.8 pC/N. The temperature dependences of the resonance frequency (TC-f) of the (33) and (15) modes of the SBNV0.1(HF) ceramics were -16.5 ppm/°C and –25.5 ppm/°C, respectively.

scholarly journals Textured ferroelectric ceramics with high electromechanical coupling factors over a broad temperature range

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shuai Yang ◽  
Jinglei Li ◽  
Yao Liu ◽  
Mingwen Wang ◽  
Liao Qiao ◽  
...  
Keyword(s):  
Single Crystals ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Ferroelectric Ceramics ◽  
Refractory Component ◽  
Temperature Range ◽  
Phase Transition Temperatures ◽  
Coupling Factors ◽  
Growth Approach

AbstractThe figure-of-merits of ferroelectrics for transducer applications are their electromechanical coupling factor and the operable temperature range. Relaxor-PbTiO3 ferroelectric crystals show a much improved electromechanical coupling factor k33 (88~93%) compared to their ceramic counterparts (65~78%) by taking advantage of the strong anisotropy of crystals. However, only a few relaxor-PbTiO3 systems, for example Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3, can be grown into single crystals, whose operable temperature range is limited by their rhombohedral-tetragonal phase transition temperatures (Trt: 60~120 °C). Here, we develop a templated grain-growth approach to fabricate <001>-textured Pb(In1/2Nb1/2)O3-Pb(Sc1/2Nb1/2)O3-PbTiO3 (PIN-PSN-PT) ceramics that contain a large amount of the refractory component Sc2O3, which has the ability to increase the Trt of the system. The high k33 of 85~89% and the greatly increased Trt of 160~200 °C are simultaneously achieved in the textured PIN-PSN-PT ceramics. The above merits will make textured PIN-PSN-PT ceramics an alternative to single crystals, benefiting the development of numerous advanced piezoelectric devices.

Precipitation of NiHfsi phase in NiAl single crystals containing Hf

1995 ◽  
Vol 53 ◽  
pp. 532-533
Author(s):  
A. Garg ◽  
R. D. Noebe ◽  
R. Darolia
Keyword(s):  
High Temperature ◽  
Single Crystals ◽  
High Temperature Strength ◽  
Bridgman Technique ◽  
Shell Mold ◽  
Third Phase ◽  
Unknown Phase ◽  
Transmission Electron ◽  
Two Phases ◽  
Nial Matrix

Small additions of Hf to NiAl produce a significant increase in the high-temperature strength of single crystals. Hf has a very limited solubility in NiAl and in the presence of Si, results in a high density of G-phase (Ni16Hf6Si7) cuboidal precipitates and some G-platelets in a NiAl matrix. These precipitates have a F.C.C structure and nucleate on {100}NiAl planes with almost perfect coherency and a cube-on-cube orientation-relationship (O.R.). However, G-phase is metastable and after prolonged aging at high temperature dissolves at the expense of a more stable Heusler (β'-Ni2AlHf) phase. In addition to these two phases, a third phase was shown to be present in a NiAl-0.3at. % Hf alloy, but was not previously identified (Fig. 4 of ref. 2 ). In this work, we report the morphology, crystal-structure, O.R., and stability of this unknown phase, which were determined using conventional and analytical transmission electron microscopy (TEM).Single crystals of NiAl containing 0.5at. % Hf were grown by a Bridgman technique. Chemical analysis indicated that these crystals also contained Si, which was not an intentional alloying addition but was picked up from the shell mold during directional solidification.

The effect of high-temperature and high-stress martensite aging on martensitic transformation and microstructure of Ti–51.5 at % Ni single crystals

2020 ◽  
Author(s):  
E. E. Timofeeva ◽  
E. Yu. Panchenko ◽  
A. S. Eftifeeva ◽  
E. I. Yanushonite ◽  
M. V. Zherdeva ◽  
...  
Keyword(s):  
High Temperature ◽  
Martensitic Transformation ◽  
Single Crystals ◽  
High Stress
Sign in / Sign up

Export Citation Format

Share Document