Growth and SAW properties of rare-earth calcium oxoborate crystals

Nishikawa, Hiroshi; Nishida, Masahiro; Shikida, Takashi; Shimizu, Hiroyuki; Takeda, Hiroaki; Shiosaki, Tadashi

doi:10.1016/j.jallcom.2004.12.153

Cited by 44 publications

(37 citation statements)

References 6 publications

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“…The melting temperature of RECOB crystals decreases with an increase in the ionic radii of the rare earth ion present in it [12]. YCOB crystal has the melting temperature of 1510°C.…”

Section: Introductionmentioning

confidence: 99%

Growth of YCOB single crystals by flux technique and their characterization

Kumar¹,

Senthilkumar²,

Dhanasekaran³

2008

Cryst. Res. Technol.

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Nonlinear optical single crystals of YCOB with good optical quality were grown by the flux technique for the first time. Polycrystalline YCOB samples were synthesized by solid state reaction method. The thermal analysis of the sample was performed with lithium carbonate flux in different weight proportions and the growth temperature was optimised. Single crystals of YCOB with dimensions 3 x 3 x 5 mm 3 were obtained by the method of 'slow-cooling'. The grown crystals were characterized by XRD, UV-VIS-NIR, EDAX, FTIR and etching studies. The powder XRD pattern revealed the formation of YCOB compound. The lattice parameters were identified through single crystal XRD studies. The UV-VIS-NIR results showed that the crystal has a sharp cutoff at 220 nm and is nearly 55% transparent over a wide wavelength range enabling applications in the UV region. The EDAX measurement revealed the 'flux-free' crystal formation. The presence of the functional groups belonging to the YCOB crystals was identified by the FTIR results. 'Hillock-like' patterns are observed in the etching studies. The primary emphasis in this study is laid to describe 'flux technique' as an alternative method to grow YCOB crystals. The results are presented and discussed.

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“…The melting temperature of RECOB crystals decreases with an increase in the ionic radii of the rare earth ion present in it [12]. YCOB crystal has the melting temperature of 1510°C.…”

Section: Introductionmentioning

confidence: 99%

Growth of YCOB single crystals by flux technique and their characterization

Kumar¹,

Senthilkumar²,

Dhanasekaran³

2008

Cryst. Res. Technol.

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“…These crystals show the merits of high melting points (1400-1700 °C) and high effective piezoelectric coefficients d eff (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) pC/N) [20][21][22][23][24][25][26]; the evaluations of the temperature dependence of dielectric, piezoelectric and electromechanical properties, however, are limited. Of particular significance is that the monoclinic rare-earth calcium oxyborate crystals (ReCa 4 O(BO 3 ) 3 , ReCOB, Re: rare earth), which have been extensively investigated for nonlinear optical applications in the last two decades [27][28][29][30][31][32][33], were reported to exhibit good piezoelectric properties and high electrical resistivity at an elevated temperature of 1000 °C, with no phase transition prior to their melting points (~1400-1520 °C) [1][2][3][34][35][36][37][38]. Table 1 summarizes the basic characteristics of various high temperature piezoelectric crystals in monoclinic, trigonal and tetragonal systems, where the monoclinic ReCOB crystals were found to exhibit relatively high melting points, as well as relatively large piezoelectric coefficients, promising high temperature piezoelectric sensor applications.…”

Section: Open Accessmentioning

confidence: 99%

Rare-Earth Calcium Oxyborate Piezoelectric Crystals ReCa4O(BO3)3: Growth and Piezoelectric Characterizations

Duan

Zhang

et al. 2014

Crystals

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Rare-earth calcium oxyborate crystals, ReCa 4 O(BO 3 ) 3 (ReCOB, Re = Er, Y, Gd, Sm, Nd, Pr, and La ), are potential piezoelectric materials for ultrahigh temperature sensor applications, due to their high electrical resistivity at elevated temperature, high piezoelectric sensitivity and temperature stability. In this paper, different techniques for ReCOB single-crystal growth are introduced, including the Bridgman and Czochralski pulling methods. Crystal orientations and the relationships between the crystallographic and physical axes of the monoclinic ReCOB crystals are discussed. The procedures for dielectric, elastic, electromechanical and piezoelectric property characterization, taking advantage of the impedance method, are presented. In addition, the maximum piezoelectric coefficients for different piezoelectric vibration modes are explored, and the optimized crystal cuts free of piezoelectric cross-talk are obtained by rotation calculations.

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“…Recently, electro-elastic properties of ReCOB type crystals, including YCOB, GdCOB, NdCOB and LaCOB, have been extensively investigated. [8][9][10][11][12][13][14][15] Among these crystals, NdCOB crystals were reported to possess a relatively high surface acoustic wave (SAW) coupling factor (k 2 = 0.8%) and low linear temperature coefficient of delay (TCD) (close to zero), 16 while YCOB crystals were observed to show high stability of electromechanical properties at elevated temperatures, 14,15 and explored for high temperature accelerometer applications. [17][18][19] In previous reports, it has been revealed that the piezoelectric coefficient d 26 and electromechanical coupling factor k 26 increase with increasing rare-earth ionic radius, the relationship between crystal structure and piezoelectric properties was established, where the distortions of Re-O and Ca-O octahedra in ReCOB crystals were believed to account for the enhancement of piezoelectric coefficient d 26.…”

Section: Motivationmentioning

confidence: 99%

Crystal growth, structure and thermal properties of noncentrosymmetric single crystals PrCa4O(BO3)3

Zhang

Cheng

et al. 2013

CrystEngComm

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X. (2013). Crystal growth, structure and thermal properties of noncentrosymmetric single crystals PrCa4O(BO3)3+. CrystEngComm, 15 (26), 5226-5231.Crystal growth, structure and thermal properties of noncentrosymmetric single crystals PrCa4O(BO3)3+ AbstractNoncentrosymmetric praseodymium calcium oxyborate single crystals, PrCa4O(BO3)3 (PrCOB), were grown by the Czochralski technique. The monoclinic unit cell parameters were found to be a = 8.177 Å, b = 16.157 Å, c = 3.629 Å and Z = 2 with space group Cm. Crystal density was measured using the Archimedes method, being on the order of 3.47 g cm-3. Thermal properties of PrCOB were investigated, where the specific heat was found to be 0.63 J g-1 °C-1 at room temperature, increasing to 0.85 J g-1°C-1 at 700°C. The thermal expansion coefficients were measured to be α11 = 7.99, α22 = 4.90 and α33 = 9.46 (10-6/°C), respectively. In addition, thermal diffusivity λ22 and thermal conductivity κ22 as a function of temperature were studied, where λ22 was observed to decrease from 0.89 to 0.58 mm2 s-1, while κ22 was found to maintain the same value, being ∼1.90 W m-1°C-1 over the temperature range of 20-700°C.

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Growth and SAW properties of rare-earth calcium oxoborate crystals

Cited by 44 publications

References 6 publications

Growth of YCOB single crystals by flux technique and their characterization

Growth of YCOB single crystals by flux technique and their characterization

Rare-Earth Calcium Oxyborate Piezoelectric Crystals ReCa4O(BO3)3: Growth and Piezoelectric Characterizations

Crystal growth, structure and thermal properties of noncentrosymmetric single crystals PrCa4O(BO3)3

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