scholarly journals Large Piezoelectric Response and Ferroelectricity in Li and V/Nb/Ta Co-Doped w-AlN

2020 ◽  
Author(s):  
Mohammad Noor-A-Alam ◽  
Oskar Z. Olszewski ◽  
Humberto Campanella ◽  
Michael Nolan
Keyword(s):  
Piezoelectric Response ◽  
Co Doped

scholarly journals Large Piezoelectric Response and Ferroelectricity in Li and V/Nb/Ta co-doped w-AlN

2020 ◽  
Author(s):  
Mohammad Noor-A-Alam ◽  
Oskar Olszewski ◽  
Humberto Campanella ◽  
Michael Nolan
Keyword(s):  
Acoustic Wave ◽  
Density Functional ◽  
Electromechanical Coupling ◽  
Piezoelectric Materials ◽  
Electric Polarization ◽  
Piezoelectric Response ◽  
Co Doping ◽  
Piezoelectric Strain ◽  
Co Doped ◽  
Piezoelectric Strain Constant

<div>Based on density functional theory, we show that Li and</div><div>X (X=V, Nb and Ta) co-doping in 1Li:1X ratio broadens the</div><div>compositional freedom for significant piezoelectric enhancement in w-AlN, promising them to be good alternatives of expensive Sc. Interestingly, these co-doped w-AlN also show quite large spontaneous electric polarization about 0.80 C/m2 with the possibility of ferroelectric polarization switching, opening new possibilities in wurtzite nitrides. Increase in piezoelectric stress constant (e33) with decrease in elastic constant ( C33 ) results enhancement in piezoelectric strain constant ( d33 ), which is desired for improving the performance of resonators for high frequency RF signals. Also, these co-doped w-AlN are potential lead-free piezoelectric materials for energy harvesting and sensors as they improve the longitudinal electromechanical coupling constant (K^2 33), transverse piezoelectric strain constant (d31), and figure of merit for power generation. However, the enhancement in K^2 33 is not as pronounced as that in d33, because co-doping increases the dielectric constant. The longitudinal acoustic wave velocity (7.09 km/s) of Li0.1875Ta0.1875Al0.625N is quite comparable with that of commercially used piezoelectric LiNbO3 or LiTaO3 in special cuts (about 5~7 km/s) despite the fact that the acoustic wave velocities drop with co-doping or Sc concentration.</div>

scholarly journals Local Piezoelectric Properties of Doped Biomolecular Crystals

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4922
Author(s):  
Andrei Kholkin ◽  
Denis Alikin ◽  
Vladimir Shur ◽  
Shiri Dishon ◽  
David Ehre ◽  
...  
Keyword(s):  
Guest Molecule ◽  
Piezoelectric Properties ◽  
Dipole Moments ◽  
Mechanical Strain ◽  
Piezoresponse Force Microscopy ◽  
Piezoelectric Response ◽  
Force Microscopy ◽  
Highly Sensitive ◽  
Molecule Interactions ◽  
Co Doped

Piezoelectricity is the ability of certain crystals to generate mechanical strain proportional to an external electric field. Though many biomolecular crystals contain polar molecules, they are frequently centrosymmetric, signifying that the dipole moments of constituent molecules cancel each other. However, piezoelectricity can be induced by stereospecific doping leading to symmetry reduction. Here, we applied piezoresponse force microscopy (PFM), highly sensitive to local piezoelectricity, to characterize (01¯0) faces of a popular biomolecular material, α-glycine, doped with other amino acids such as L-alanine and L-threonine as well as co-doped with both. We show that, while apparent vertical piezoresponse is prone to parasitic electrostatic effects, shear piezoelectric activity is strongly affected by doping. Undoped α-glycine shows no shear piezoelectric response at all. The shear response of the L-alanine doped crystals is much larger than those of the L-threonine doped crystals and co-doped crystals. These observations are rationalized in terms of host–guest molecule interactions.

scholarly journals Large Piezoelectric Response and Ferroelectricity in Li and V/Nb/Ta co-doped w-AlN

2020 ◽  
Author(s):  
Mohammad Noor-A-Alam ◽  
Oskar Olszewski ◽  
Humberto Campanella ◽  
Michael Nolan
Keyword(s):  
Acoustic Wave ◽  
Density Functional ◽  
Electromechanical Coupling ◽  
Piezoelectric Materials ◽  
Electric Polarization ◽  
Piezoelectric Response ◽  
Co Doping ◽  
Piezoelectric Strain ◽  
Co Doped ◽  
Piezoelectric Strain Constant

<div>Based on density functional theory, we show that Li and</div><div>X (X=V, Nb and Ta) co-doping in 1Li:1X ratio broadens the</div><div>compositional freedom for significant piezoelectric enhancement in w-AlN, promising them to be good alternatives of expensive Sc. Interestingly, these co-doped w-AlN also show quite large spontaneous electric polarization about 0.80 C/m2 with the possibility of ferroelectric polarization switching, opening new possibilities in wurtzite nitrides. Increase in piezoelectric stress constant (e33) with decrease in elastic constant ( C33 ) results enhancement in piezoelectric strain constant ( d33 ), which is desired for improving the performance of resonators for high frequency RF signals. Also, these co-doped w-AlN are potential lead-free piezoelectric materials for energy harvesting and sensors as they improve the longitudinal electromechanical coupling constant (K^2 33), transverse piezoelectric strain constant (d31), and figure of merit for power generation. However, the enhancement in K^2 33 is not as pronounced as that in d33, because co-doping increases the dielectric constant. The longitudinal acoustic wave velocity (7.09 km/s) of Li0.1875Ta0.1875Al0.625N is quite comparable with that of commercially used piezoelectric LiNbO3 or LiTaO3 in special cuts (about 5~7 km/s) despite the fact that the acoustic wave velocities drop with co-doping or Sc concentration.</div>

scholarly journals Temperature-Dependent Ferroelectric and Piezoelectric Response of Yb3+ and Tm3+ co-Doped Ba0.95Ca0.05Ti0.90Zr0.10O3 Lead-Free Ceramic

2020 ◽  
Author(s):  
Yongshang Tian ◽  
Qiqi Wang ◽  
Bingqian Zhang ◽  
Panpan Qin ◽  
Yansheng Gong ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Orthorhombic Phase ◽  
Lead Free ◽  
Piezoelectric Response ◽  
Structural Defects ◽  
Future Research ◽  
Electrical Measurements ◽  
Temperature Dependent ◽  
Lead Free Ceramic ◽  
Co Doped

Abstract The electrical properties of piezoelectric ceramics are temperature-dependent, which affects their potential for applications in environments with temperature variation. In this work, a Yb3+ and Tm3+ co-doped Ba0.95Ca0.05Ti0.90Zr0.10O3 (BCTZ-YT) dense lead-free ceramic was prepared using a modified polymeric precursor route. The structural characteristics were investigated by X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. The temperature-dependence of the ferroelectricity, piezoelectricity, and permittivity was studied in detail. On the basis of structural and electrical measurements at various temperatures, the mechanism of a lack of oxygen vacancies, small structural defects, and small defect dipoles was deduced. This study reveals that the ferroelectricity and piezoelectricity are temperature-dependent, whereas the capacitance is essentially unchanged with increasing temperature owing to the presence of a pure orthorhombic phase. The results of this study are expected to inform future research.

scholarly journals Two-step doping approach releasing the piezoelectric response of BiFeO3 bulk ceramics co-doped with titanium and samarium

2020 ◽  
Vol 59 (2) ◽  
pp. 81-87
Author(s):  
Carlos Gumiel ◽  
Mara S. Bernardo ◽  
Pablo G. Villanueva ◽  
David G. Calatayud ◽  
Marco Peiteado ◽  
...  
Keyword(s):  
Piezoelectric Response ◽  
Co Doped

Phase diagram determination of large piezoelectric response in BHT-BCT ceramics

2019 ◽  
Vol 12 (05) ◽  
pp. 1950070 ◽  
Author(s):  
Zhonghua Dai ◽  
Dingyan Li ◽  
Jinglong Xie ◽  
Weiguo Liu ◽  
Shaobo Ge ◽  
...  
Keyword(s):  
Phase Diagram ◽  
High Performance ◽  
Piezoelectric Properties ◽  
Piezoelectric Materials ◽  
Electronic Devices ◽  
Lead Free ◽  
Piezoelectric Response ◽  
Cubic Phases ◽  
Co Doped

High-performance lead-free piezoelectric materials are environmentally friendly and in great demand for electronic devices. In this study, the phase diagram and properties of Hf, Ca co-doped BaTiO3 (BHT-BCT) were investigated. A triple-point morphotropic phase boundary separating the rhombohedral, tetragonal and cubic phases for the (1-[Formula: see text])Ba(Ti0.85Hf0.15)O3-[Formula: see text](Ba0.7Ca0.3)TiO3 system exited at [Formula: see text] High piezoelectric properties with piezoelectric coefficients [Formula: see text] (572pC/N) and Curie temperature [Formula: see text] (90∘C) of 0.55Ba(Ti0.85Hf0.15)O3-0.45(Ba0.7Ca0.3)TiO3 are achieved in the BaTiO3-based ceramics.

Piezoelectric response of pulsed laser deposited heterostructures PZT/YBCO, PLZT/YBCO

1998 ◽  
Vol 08 (PR9) ◽  
pp. Pr9-183-Pr9-186
Author(s):  
M. Tyunina ◽  
A. Sternberg ◽  
V. Zauls ◽  
M. Kundzinsh ◽  
I. Shorubalko
Keyword(s):  
Pulsed Laser ◽  
Piezoelectric Response

970 nm Infrared to Visible Upconversion in Er3+ and Yb3+ Co-Doped PLZT Glass Ceramic Thin Films

2008 ◽  
Author(s):  
Xiaomei Guo ◽  
Kewen Kevin. Li ◽  
Xuesheng Chen ◽  
Yingyin Kevin. Zou ◽  
Hua Jiang
Keyword(s):  
Thin Films ◽  
Glass Ceramic ◽  
Ceramic Thin Films ◽  
Co Doped
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