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Journal ArticleDOI

Plasma Enhanced Chemical Vapour Deposition of Hydrogenated Amorphous Silicon from Dichlorosilane and Silane Gas Mixtures.

01 May 1995-Japanese Journal of Applied Physics (IOP Publishing)-Vol. 34, Iss: 5, pp 536-538
TL;DR: In this paper, hydrogenated amorphous silicon films have been deposited from mixtures of dichlorosilane (SiH2Cl2) and silane by plasma enhanced chemical vapour deposition.
Abstract: Hydrogenated amorphous silicon films have been deposited from mixtures of dichlorosilane ( SiH2Cl2) and silane by plasma enhanced chemical vapour deposition. The deposition rate is found to increase with the addition of SiH2Cl2. At a given rf power, the deposition rate decreases with increasing total flow rate, opposite to that found for deposition with only silane. These results are compared to optical emission data measured under identical deposition conditions, and are discussed in terms of electron attachment to the chlorinated species which modifies the electron energy distribution within the plasma.
Citations
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Journal ArticleDOI
TL;DR: In this article, the piezoelectric properties of relaxor based ferroelectric single crystals, such as Pb(Zn1/3Nb2/3)O3 and PbTiO3, were investigated for electromechanical actuators.
Abstract: The piezoelectric properties of relaxor based ferroelectric single crystals, such as Pb(Zn1/3Nb2/3)O3–PbTiO3 and Pb(Mg1/3Nb2/3)O3–PbTiO3 were investigated for electromechanical actuators. In contrast to polycrystalline materials such as Pb(Zr,Ti)O3, morphotropic phase boundary compositions were not essential for high piezoelectric strain. Piezoelectric coefficients (d33’s)>2500 pC/N and subsequent strain levels up to >0.6% with minimal hysteresis were observed. Crystallographically, high strains are achieved for 〈001〉 oriented rhombohedral crystals, although 〈111〉 is the polar direction. Ultrahigh strain levels up to 1.7%, an order of magnitude larger than those available from conventional piezoelectric and electrostrictive ceramics, could be achieved being related to an E-field induced phase transformation. High electromechanical coupling (k33)>90% and low dielectric loss <1%, along with large strain make these crystals promising candidates for high performance solid state actuators.

3,766 citations

Journal ArticleDOI
TL;DR: In this paper, material development of the piezoelectric ceramic and new opportunities for higher temperature materials are discussed, and an important consideration in developing low fire ceramics is the flux selection for a given system, and these must be selected to limit electrode-ceramic interface reactions in both Ag/Pd and copper-metallized electrode actuators.
Abstract: Piezoelectric actuators are at an important stage of their development into a large component market. This market pull is for dynamically driven actuators for Diesel injector valves in automobiles. Cost, yield, and reliability are important concerns for the automobile industry. A number of these concerns relate back to basic material science issues in the manufacture of the piezoelectric actuators. This paper discusses material development of the piezoelectric ceramic and new opportunities for higher temperature materials. An important consideration in developing low-fire ceramics is the flux selection for a given system, and these must be selected to limit electrode-ceramic interface reactions in both Ag/Pd and copper-metallized electrode actuators.

215 citations

Journal ArticleDOI
TL;DR: The history of piezoelectric perovskites is reviewed and forecasts future development trends, including Uchino’s discoveries such as the Pb(Mg1/3Nb2/3)O3–PbTiO3 electrostrictor, and five key trends in the development of Piezomaterials: performance to reliability, hard to soft, macro to nano, homo to hetero, and single to multi-functional.

91 citations

Book ChapterDOI
01 Jan 2010
TL;DR: In this paper, the authors review the historical episodes of piezoelectric materials in the sequence of quartz, Rochelle salt, barium titanate, PZT, lithium niobate/tantalate, relaxor ferroelectrics, PVDF, Pb-free, and composites.
Abstract: Certain materials produce electric charges on their surfaces as a consequence of applying mechanical stress. The induced charges are proportional to the mechanical stress. This is called the direct piezoelectric effect and was discovered in quartz by Pierre and Jacques Curie in 1880. Materials showing have a geometric strain proportional to an applied electric field. This is the converse piezoelectric effect, discovered by Gabriel Lippmann in 1881. This article first reviews the historical episodes of piezoelectric materials in the sequence of quartz, Rochelle salt, barium titanate, PZT, lithium niobate/tantalate, relaxor ferroelectrics, PVDF, Pb-free piezoelectrics, and composites. Then, the detailed performances are described in the following section, which serves as the introduction to each chapter in this book. Third, since piezoelectricity is utilized extensively in the fabrication of various devices such as transducers, sensors, actuators, surface acoustic wave devices, frequency control, etc., applications of piezoelectric materials are introduced briefly in conjunction with materials. The author hopes that the reader can ‘learn the history aiming at creating a new perspective for the future of piezoelectric materials’.

73 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of fabrication condition on the growth of Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) single crystals was studied.
Abstract: Piezoelectric single crystals of Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) show superior properties to piezoelectric ceramics and piezoelectric films in device applications. However, the applications of PMN–PT single crystals are limited by the lack of a simple and reproducible fabrication technique. By studying the effect of fabrication condition on the growth of PMN–PT single crystals in the flux method, we successfully obtained PMN-PT single crystals. The size of the obtained crystals varied from 1 to 4 mm, mostly showing regular cubic shape. X-ray diffraction technique identified the crystal phase was PMN–PT. Electron diffraction spectroscope analysis indicated that the composition of the single crystals was closed to the designed solid solution. The (0 0 1) single crystals showed a dielectric constant peak of 15,200 at 42°C. The crystals had a remnant polarization 16 μc/cm2, a spontaneous polarization 22.1 μc/cm2, and a coercive field 2.55 kV/cm. Our measurement indicated the temperature dependence and frequency dependence of the dielectric constant and dielectric loss of PMN–PT single crystals. The results will be a great help for the applications of PMN–PT single crystals.

37 citations

References
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Journal ArticleDOI
TL;DR: In this paper, negative ions were only observed over a limited range of power modulation frequency which corresponds to particle-free plasma conditions, and the importance of negative ions regarding particulate formation was demonstrated and commented upon.
Abstract: Negative ions have been clearly identified in silane rf plasmas used for the deposition of amorphous silicon. Mass spectra were measured for monosilicon up to pentasilicon negative ion radical groups in power‐modulated plasmas by means of a mass spectrometer mounted just outside the glow region. Negative ions were only observed over a limited range of power modulation frequency which corresponds to particle‐free plasma conditions. The importance of negative ions regarding particulate formation is demonstrated and commented upon.

109 citations