Crystal Structure and Piezoelectric Properties of Four Component Langasite A₃B Ga₃Si₂O₁₄ (A = Ca or Sr, B = Ta or Nb)

Ohsato, Hitoshi,Iwataki, Tsuyoshi,Morikoshi, Hiroki The Korean Institute of Electrical and Electronic 2012 Transactions on Electrical and Electronic Material Vol.13 No.4

As langasite $A_3BC_3D_2O_{14}$ compounds with piezoelectric properties exhibit no phase transition up to the melting point of 1,400-$1,500^{\circ}C$, many high temperature applications are expected for the SAW filter, temperature sensor, pressure sensor, and so on, based on the digital transformation of wider bandwidth and higher-bit rates. It has a larger electromechanical coupling factor compared to quartz and also nearly the same temperature stability as quartz. The $La_3Ga_5SiO_{14}$ (LGS) crystal with the $Ca_3Ga_2Ge_4O_{14}$-type crystal structure was synthesized and the crystal structure was analyzed by Mill et al. It is also an important feature that the growth of the single crystal is easy. In the case of three-element compounds such as $[R_3]_A[Ga]_B[Ga_3]_C[GaSi]_DO_{14}$ (R=La, Pr and Nd), the piezoelectric constant increases with the ionic radius of R. In this study, crystal structures of four-element compounds such as $[A_3]_A[B]_B[Ga_3]_C[Si_2]_DO_{14}$ (A = Ca or Sr, B = Ta or Nb) are analyzed by a single crystal X-ray diffraction, and the mechanism and properties of the piezoelectricity depending on the species of cation was clarified based on the crystal structure.

Crystal growth, optical and luminescence properties of Na₆Mo₁₁O₃₆ single crystal

Pandey, Indra Raj,Karki, Sujita,Kim, H.J.,Lee, M.H.,Kim, Y.D. Elsevier 2019 Journal of crystal growth Vol.512 No.-

<P><B>Abstract</B></P> <P>The inorganic material Na<SUB>6</SUB>Mo<SUB>11</SUB>O<SUB>36</SUB> was synthesized by solid-state reaction, and a single crystal of the compound was grown using the Czochralski technique. The crystal structure of the compound was confirmed by X-ray diffraction (XRD) analysis. The luminescence light yield and fluorescence decay time of the crystal were studied in a temperature range from room temperature to 10 K using a 280 nm light emitting diode (LED) source. The Na<SUB>6</SUB>Mo<SUB>11</SUB>O<SUB>36</SUB> crystal has no luminescence at room temperature, however, the luminescence intensity is enhanced at low temperatures. Transmittance spectrum measurement was performed to study the optical quality of the crystal. The luminescence light yield of the Na<SUB>6</SUB>Mo<SUB>11</SUB>O<SUB>36</SUB> was compared with that of a Li<SUB>2</SUB>MoO<SUB>4</SUB> crystal at different low temperatures. Because of the possibility of growing a single crystal of Na<SUB>6</SUB>Mo<SUB>11</SUB>O<SUB>36</SUB>, which has a significant luminescence light yield at 10 K and no heavy elements, this crystal can be a good candidate for a rare event search experiment searching for neutrinoless double beta (0νββ) decay at cryogenic temperatures.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Single crystals of Na<SUB>6</SUB>Mo<SUB>11</SUB>O<SUB>36</SUB> is grown for first time. </LI> <LI> Powder XRD result of Na<SUB>2</SUB>Mo<SUB>4</SUB>O<SUB>13</SUB> and Na<SUB>6</SUB>Mo<SUB>11</SUB>O<SUB>36</SUB> compound shows that, both compound has almost the same phase. </LI> <LI> Luminescence properties of new Na<SUB>6</SUB>Mo<SUB>11</SUB>O<SUB>36</SUB> crystal is reported. </LI> <LI> The luminescence result of Na<SUB>6</SUB>Mo<SUB>11</SUB>O<SUB>36</SUB> at 10 K is compared with Li<SUB>2</SUB>MoO<SUB>4</SUB> crystal. </LI> <LI> At 10 K, luminescence light yield of Na<SUB>6</SUB>Mo<SUB>11</SUB>O<SUB>36</SUB> is almost double than Li<SUB>2</SUB>MoO<SUB>4</SUB> crystal. </LI> </UL> </P>

Crystal Structure and Piezoelectric Properties of Four Component Langasite A3B Ga3Si2O14 (A = Ca or Sr, B = Ta or Nb)

HitoshiOhsato,Tsuyoshi Iwataki,Hiroki Morikoshi 한국전기전자재료학회 2012 Transactions on Electrical and Electronic Material Vol.13 No.4

As langasite A3BC3D2O14 compounds with piezoelectric properties exhibit no phase transition up to the melting point of 1,400-1,500℃, many high temperature applications are expected for the SAW filter, temperature sensor, pressure sensor, and so on, based on the digital transformation of wider bandwidth and higher-bit rates. It has a larger electromechanical coupling factor compared to quartz and also nearly the same temperature stability as quartz. The La3Ga5SiO14 (LGS) crystal with the Ca3Ga2Ge4O14-type crystal structure was synthesized and the crystal structure was analyzed by Mill et al. It is also an important feature that the growth of the single crystal is easy. In the case of threeelement compounds such as [R3]A[Ga]B[Ga3]C[GaSi]DO14 (R=La, Pr and Nd), the piezoelectric constant increases with the ionic radius of R. In this study, crystal structures of four-element compounds such as [A3]A[B]B[Ga3]C [Si2]DO14 (A = Ca or Sr, B = Ta or Nb) are analyzed by a single crystal X-ray diffraction, and the mechanism and properties of the piezoelectricity depending on the species of cation was clarified based on the crystal structure.

Synthesis and Crystal Structure of Zinc Iodide in the Sodalite Cavities of Zeolite A (LTA)

Kim, Seok-Han,Park, Man,Son, Young-Ja,Lee, Hyung-Joo,Jeong, Gyo-Cheol,Bae, Myung-Nam,Lim, Woo-Taik Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.4

The crystal structure of ZnI2 molecule synthesized in zeolite A (LTA) has been studied by single-crystal X-ray diffraction techniques. A single crystal of |Zn6|[Si12Al12O48]-LTA, synthesized by the dynamic ion-exchange of |Na12|[Si12Al12O48]-LTA with aqueous 0.05 M Zn(NO3)2 and washed with deionized water, was placed in a stream of flowing 0.05 M KI in CH3OH at 294 K for four days. The resulting crystal structure of the product (|K6Zn3(KI)3(ZnI2)0.5|[Si12Al12O48]-LTA, a = 12.1690(10) A) was determined at 294 K by single-crystal X-ray diffraction in the space group Pm3m. It was refined with all measured reflections to the final error index R1 = 0.078 for 431 reflections which Fo > 4σ (Fo). At four crystallographically distinct positions, 3.5 Zn2+ and nine K+ ions per unit cell are found: three Zn2+ and five K+ ions lie on the 3-fold axes opposite 6-rings in the large cavity, two K+ ions are off the plane of the 8-rings, two K+ ions are recessed deeply off the plane of the 8-rings, and the remaining a half Zn2+ ion lie on the 3-fold axes opposite 6-rings in the sodalite cavity. A half Zn2+ ion and an I- ion per unit cell are found in the sodalite units, indicating the formation of a ZnI2 molecule in 50% of the sodalite cavities. Each ZnI2 (Zn-I = 3.35(5) A) is held in place by the coordination of its one Zn2+ ion to the zeolite framework oxygens and by the coordination of its two I- ions to K+ ions through 6-rings (I-K = 3.33(8) A). Three additional I- ions per unit cell are found opposite a 4-ring in the large cavity and form a K3I2+ and two K2ZnI3+ ionic clusters, respectively.

Single-crystal Structure of Fully Dehydrated and Largely NH4 +-exchanged Zeolite Y (FAU, Si/Al = 1.70), |(NH4)60Na11|[Si121Al71O384]-FAU

Sung Man Seo,김경화,Young Hun Kim,Gao Qing Lu,임우택 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.3

The single-crystal structure of largely ammonium-exchanged zeolite Y dehydrated at room temperature (293 K) and 1 × 10-6 Torr. has been determined using synchrotron X-radiation in the cubic space group Fd 3m (a = 24.9639(2) Å) at 294 K. The structure was refined to the final error index R1 = 0.0429 with 926 reflections where Fo > 4σ(Fo); the composition (best integers) was identified as |(NH4)60Na11|[Si121Al71O384]-FAU. The 11 Na+ ions per unit cell were found at three different crystallographic sites and 60 NH4 + ions were distributed over three sites. The 3 Na+ ions were located at site I, the center of the hexagonal prism (Na-O = 2.842(5) Å and O-Na-O = 85.98(12)o). The 4 Na+ and 22 NH4 + ions were found at site I' in the sodalite cavity opposite the double 6-rings, respectively (Na-O = 2.53(13) Å, O-Na-O = 99.9(7)o, N-O = 2.762(11) Å, and O-N-O = 89.1(5)o). About 4 Na+ ions occupied site II (Na-O = 2.40(4) Å and O-Na-O = 108.9(3)o) and 29 NH4 + ions occupy site II (N-O = 2.824(9) Å and O-N-O = 87.3(3)o) opposite to the single 6-rings in the supercage. The remaining 9 NH4 + ions were distributed over site III' (N-O = 2.55(3), 2.725(13) Å and O-N-O = 94.1(13), 62.16(15), 155.7(14)o).

Crystal Structure, 7Li NMR, and Structural Relationship of Two Rare-Earth Metal Richer Polar Intermetallics: La15Ge9Li1.50(16) and La7Ge3

Gnu Nam,조홍일,옥강민,김종식,유태수 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.8

Two novel polar intermetallic compounds have been synthesized by a high-temperature reaction method, and their crystal structures have been characterized by both single-crystal and powder X-ray diffractions. La15Ge9Li1 .50(16) crystallizes in the hexagonal space group P63 mc (Z = 2, Pearson code hP52) with nine crystallographically independent sites in the unit cell, and the lattice parameters are a = 15.516(2) and c = 6.895(2) Å. The overall crystal structure can be described as a √3 × √3 × 1 superstructure of the parent compound La5Ge3 adopting the Mn5Si3-type, and such a superstructure transformation should be attributed to the particular ordering patterns of interstitial Li atoms at the Wyckoff 2a and 2b sites with different occupation factors. La7Ge3 also crystallizes in the hexagonal P63 mc space group (Z = 2, Pearson code hP20) with three La and one Ge non-equivalent sites in the unit cell. The lattice parameters are a = 10.666(1) and c = 6.357(1) Å. The crystal structure of La7Ge3 shares some similarities with La15Ge9Li1.50(16) and its parent compound La5Ge3, such as the one-dimensional (1D) zigzag confacial La6 octahedra chains and the 1D zigzag La atomic chains. Theoretical investigations using tight-binding linear muffin-tin orbital (LMTO) method provide a comprehensive understanding about electronic structures and chemical bonding of two title compounds based upon density of states (DOS) and crystal orbital Hamilton population (COHP) analyses. The solid-state 7Li NMR spectrum measurement proves the existence of two independent interstitial Li positions at two distinctive octahedral sites in La15Ge9Li1.50(16).

Single-crystal Structure of Fully Dehydrated and Largely NH₄⁺-exchanged Zeolite Y (FAU, Si/Al = 1.70), │(NH₄)₆₀Na₁₁│[Si₁₂₁Al₇₁O₃₈₄]-FAU

Seo, Sung-Man,Kim, Ghyung-Hwa,Kim, Young-Hun,Wang, Lian-Zhou,Lu, Gao-Qing,Lim, Woo-Taik Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.3

The single-crystal structure of largely ammonium-exchanged zeolite Y dehydrated at room temperature (293 K) and 1 ${\times}\;10^{-6}$ Torr. has been determined using synchrotron X-radiation in the cubic space group $Fd\overline{3}m\;(a=24.9639(2)\AA)$ at 294 K. The structure was refined to the final error index $R_1$ = 0.0429 with 926 reflections where $F_o>4\sigma(F_o)$; the composition (best integers) was identified as |$(NH_4)_{60}Na_{11}$|[$Si_{121}Al_{71}O_{384}$]-FAU. The 11 $Na^{+}$ ions per unit cell were found at three different crystallographic sites and 60 ${NH_4}^{+}$ ions were distributed over three sites. The 3 $Na^{+}$ ions were located at site I, the center of the hexagonal prism ($Na-O\;=\;2.842(5)\;\AA\;and\;O-Na-O\;=\;85.98(12)^{\circ}$). The 4 $Na^{+}$ and 22 ${NH_4}^{+}$ ions were found at site I' in the sodalite cavity opposite the double 6-rings, respectively ($Na-O\;=\;2.53(13)\;\AA,\;O-Na-O\;=\;99.9(7)^{\circ},\;N-O\;=\;2.762(11)\;\AA,\;and\;O-N-O =\;89.1(5)^{\circ}$). About 4 $Na^{+}$ ions occupied site II ($(Na-O\;=\;2.40(4)\;\AA\;and\;O-Na-O\;=\;108.9(3)^{\circ}$) and 29 ${NH_4}^{+}$ ions occupy site II ($N-O\;=\;2.824(9)\;\AA\;and\;O-N-O\;=\;87.3(3)^{\circ}$) opposite to the single 6-rings in the supercage. The remaining 9 ${NH_4}^{+}$ ions were distributed over site III' ($N-O\;=\;2.55(3),\;2.725(13)\;\AA\;and\;O-N-O\;=\;94.1(13),\;62.16(15),\;155.7(14)^{\circ}$).

Crystal Structure and Morphology of Poly(16-hexadecalactone) Chain-folded Lamellar Crystals

Kim, Eunju,Uyama, Hiroshi,Doi, Yoshiharu,Ha, Chang-Sik,Iwata, Tadahisa WILEY-VCH Verlag 2005 Macromolecular bioscience Vol.5 No.8

<P>Summary: Solution-grown, chain-folded lamellar crystals of poly(16-hexadecalactone) (PHDL) were crystallized isothermally from 1-hexanol at 70 °C. The morphology of lozenge-shaped crystals was studied by TEM and AFM. The lamellae are ca. 10 nm thick and the chains run orthogonal to the lamellar surface with folding along (110) and (<TEX>$1\bar 10$</TEX>) planes. The crystal structure of PHDL was determined by XRD and election diffraction of single crystals. The chains are in the 2<SUB>1</SUB> helix conformation close to all-trans and the structure consists of an orthorhombic unit cell with a P2<SUB>1</SUB>2<SUB>1</SUB>2<SUB>1</SUB> space group with the lattice constants a = 0.746 ± 0.001 nm, b = 0.504 ± 0.001 nm, and c (chain axis) = 4.116 ± 0.003 nm. There are two chains per unit cell, which exist in an antiparallel arrangement. Molecular packing structure has been studied in detail, taking into account both diffraction data and energy calculations. The setting angles, with respect to a axis, were ±40° for the corner and center chains, respectively. By using the electron and XRD data, the best molecular packing model was refined to R-factors of 0.168 and 0.196, respectively. A brief comparison of chain-packing structure is also made with related polymer structures.</P><P> <img src='wiley_img/16165187-2005-5-8-MABI200500038-gra001.gif' alt='wiley_img/16165187-2005-5-8-MABI200500038-gra001'> Graphic </P>

Synthesis and Crystal Structure of Zinc Iodide in the Sodalite Cavities of Zeolite A (LTA)

김석한,박만,Young Ja Son,이형주,정교철,Myung Nam Bae,임우택 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.4

The crystal structure of ZnI2 molecule synthesized in zeolite A (LTA) has been studied by single-crystal X-ray diffraction techniques. A single crystal of |Zn6|[Si12Al12O48]-LTA, synthesized by the dynamic ion-exchange of |Na12|[Si12Al12O48]-LTA with aqueous 0.05 M Zn(NO3)2 and washed with deionized water, was placed in a stream of flowing 0.05 M KI in CH3OH at 294 K for four days. The resulting crystal structure of the product (|K6Zn3(KI)3(ZnI2)0.5|[Si12Al12O48]-LTA, a = 12.1690(10) ) was determined at 294 K by single-crystal X-ray diffraction in the space group Pmm. It was refined with all measured reflections to the final error index R1 = 0.078 for 431 reflections which Fo > 4s (Fo). At four crystallographically distinct positions, 3.5 Zn2+ and nine K+ ions per unit cell are found: three Zn2+ and five K+ ions lie on the 3-fold axes opposite 6-rings in the large cavity, two K+ ions are off the plane of the 8-rings, two K+ ions are recessed deeply off the plane of the 8-rings, and the remaining a half Zn2+ ion lie on the 3-fold axes opposite 6-rings in the sodalite cavity. A half Zn2+ ion and an I?- ion per unit cell are found in the sodalite units, indicating the formation of a ZnI2 molecule in 50% of the sodalite cavities. Each ZnI2 (Zn-I = 3.35(5) ) is held in place by the coordination of its one Zn2+ ion to the zeolite framework oxygens and by the coordination of its two I?- ions to K+ ions through 6-rings (I-K = 3.33(8) ). Three additional I?- ions per unit cell are found opposite a 4-ring in the large cavity and form a K3I2+ and two K2ZnI3+ ionic clusters, respectively.

Synthesis of Fully Dehydrated Partially Cs+-exchanged Zeolite Y (FAU, Si/Al = 1.56), |Cs45Na30|[Si117Al75O384]-FAU and Its Single-crystal Structure

Sung Man Seo,Ghyung Hwa Kim,Seok Hee Lee,Jun-seok Bae,임우택 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.6

Large single crystals of zeolite, |Na75|[Si117Al75O384]-FAU (Na-Y, Si/Al = 1.56), were synthesized from gels with composition of 3.58SiO2 : 2.08NaAlO2 : 7.59NaOH : 455H2O : 5.06TEA : 2.23TCl. One of these, a colorless single-crystal was ion exchanged by allowing aqueous 0.02 M CsOH to flow past the crystal at 293 K for 3 days, followed by dehydration at 673 K and 1 × 10-6 Torr for 2 days. The crystal structure of fully dehydrated partially Cs+-exchanged zeolite Y, |Cs45Na30|[Si117Al75O384]-FAU per unit cell (a = 24.9080(10) Å) was determined by single-crystal X-ray diffraction technique in the cubic space group Fd 3 m at 294(1) K. The structure was refined using all intensities to the final error indices (using only the 877 reflections with Fo > 4σ(Fo)) R1 = 0.0966 (Based on F) and R2 = 0.2641 (Based on F2). About forty-five Cs+ ions per unit cell are found at six different crystallographic sites. The 2 Cs+ ions occupied at site I, at the centers of double 6-ring (D6Rs, Cs-O = 2.774(10) Å and O-Cs-O = 88.9(3) and 91.1(3)o). Two Cs+ ions are found at site I’ in the sodalite cavity; the Cs+ ions were recessed 2.05 Å into the sodalite cavity from their 3-oxygen plane (Cs-O = 3.05(3) Å and O-Cs-O = 77.4(13)o). Site-II’ positions (opposite single 6-rings in the sodalite cage) are occupied by 7 Cs+ ions, each of which extends 2.04 Å into the sodalite cage from its 3-oxygen plane (Cs-O = 3.067(11) Å and O-Cs-O = 80.1(3)o). The 26 Cs+ ions are nearly three-quarters filled at site II in the supercage, being recessed 2.34 Å into the supercage (Cs-O = 3.273(8) Å and O-Cs-O = 74.3(3)o). The 4 Cs+ ions are found at site III deep in the supercage (Cs-O = 3.321(19) and 3.08(3) Å), and 4 Cs+ ions at another site III’ (Cs-O = 2.87(4) and 3.38(4) Å). About 30 Na+ ions per unit cell are found at one crystallographic site; The Na+ ions are located at site I’ in the sodalite cavity opposite double 6-rings (Na-O =2.578(11) Å and O-Na-O = 97.8(4)o).