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)

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.

로버트 스밋슨의 광물학 탐구와 결정 구조의 반향

정은영 서양미술사학회 2024 서양미술사학회논문집 Vol.60 No.-

어린 시절 광물 수집을 시작한 로버트 스밋슨(Robert Smithson, 1938-1973)은 원자들의 규칙적인 결합으로 이루어진 광물의 결정 구조를 지속적으로 탐구했다. 특히 규칙성과 반복성을 특징으로 하는 광물의 결정 격자는 그가 당대의 미술과 사회를 바라보고 분석하는 정신적, 시각적 프레임을 제공하였다. 본 연구는 스밋슨의 광물학적 탐구와 결정 구조에 대한 천착이 그의 사유와 작품에 어떤 양상으로 나타나는지를 분석하는 데에 그 목적이 있다. 이를 위해 본고는 1960년대 중후반의 작업에 집중하여 스밋슨의 비평적 저술과 시각예술 작품에 나타나는 결정 구조의 복합적인 반향을 분석한다. 스밋슨은 광물의 결정 격자 구조로부터 논리적 언어의 붕괴, 원근법적 시각의 소멸, 시간과 공간의 비활성화를 발견하고 이를 비평과 조각으로 가시화하였다. 광물의 결정 구조에서 발견한 논리와 시각의 와해 및 시공간의 쇠락은 스밋슨이 1960년대의 미국 사회와 인류의 문명을 진보나 발전이 부재하는 엔트로피의 세계로 바라보는 데 큰 영향을 미쳤다. 동시에 그는 광물의 지도라 할 수 있는 결정 격자로부터 물리적 공간을 탐사하고 측정하는 측량자의 시각을 복권하고 새로운 지도 제작을 수행함으로써 결정체의 소우주에서 대지와 지구의 넓은 세계로 나아갈 수 있었다. 본 연구는 광물 결정의 엔트로픽한 평형 상태가 스밋슨의 사유와 작업에 미친 복합적인 영향을 분석하고, 이를 기반으로 결정에 대한 탐구가 이후 스밋슨이 진행한 대지미술 작업의 중요한 기반이 되었음을 제시한다. Robert Smithson (1938-1973), who started collecting minerals as a child, continued to explore the crystal structure of minerals consisting of highly ordered bonds of atoms. The crystal structure of minerals provided him with a mental and visual frame in which he envisioned the art and society of his time. The purpose of this study is to analyze how Smithson's mineralogical exploration and inquiry into crystal structure affected his thoughts and works. To this end, the author focuses on Smithson's critical writings and artworks from the mid-to-late 1960s and examines the complex repercussions of the crystal structure he has long explored. For Smithson the lattice structure of crystals was both a metaphor and a material evidence for the collapse of logical language, the disappearance of perspectival vision, and the inertness of time and space. At the same time, however, he was able to move towards the open field of land and earth by considering the crystal lattice as a structuralist map and creating his own maps with the surveyor’s vision that he recovered from the cartography of crystal structure. Based on the analysis of the ramifications of the entropic equilibrium of crystal structure in Smithson’s thought and work, the author suggests that Smithson’s mineralogical explorations continued to inform his later land art.

Crystal Structure of XoLAP, a Leucine Aminopeptidase, from Xanthomonas oryzae pv. oryzae

김진광,Sampath Natarajan,박한슬,Kim-Hung Huynh,이상희,김정구,안예진,강린우 한국미생물학회 2013 The journal of microbiology Vol.51 No.5

Aminopeptidases are metalloproteinases that degrade N-terminal residues from protein and play important roles in cell growth and development by controlling cell homeostasis and protein maturation. We determined the crystal structure of XoLAP, a leucyl aminopeptidase, at 2.6 Å resolution from Xanthomonas oryzae pv. oryzae, causing the destructive rice disease of bacterial blight. It is the first crystal structure of aminopeptidase from phytopathogens as a drug target. XoLAP existed as a hexamer and the monomer structure consisted of an N-terminal cap domain and a C-terminal peptidase domain with two divalent zinc ions. XoLAP structure was compared with BlLAP and EcLAP (EcPepA) structures. Based on the structural comparison, the molecular model of XoLAP in complex with the natural aminopeptidase inhibitor of microginin FR1 was proposed. The model structure will be useful to develop a novel antibacterial drug against Xoo.

Crystal structure of a Fanconi anemia-associated nuclease homolog bound to 5′ flap DNA: basis of interstrand cross-link repair by FAN1

Gwon, Gwang Hyeon,Kim, Youngran,Liu, Yaqi,Watson, Adam T.,Jo, Aera,Etheridge, Thomas J.,Yuan, Fenghua,Zhang, Yanbin,Kim, YoungChang,Carr, Anthony M.,Cho, Yunje Cold Spring Harbor Laboratory Press 2014 Genes & development Vol.28 No.20

<P>Fanconi anemia (FA) is an autosomal recessive genetic disorder caused by defects in FA genes responsible for processing DNA interstrand cross-links (ICLs). FA-associated nuclease (FAN1) is recruited to lesions by a monoubiquitinated FANCI–FANCD2 (ID) complex and participates in ICL repair. Here, Gwon et al. determined the crystal structure of <I>Pseudomonas aeruginosa</I> FAN1 (<I>Pa</I>FAN1) lacking the UBZ (ubiquitin-binding zinc) domain in complex with 5′ flap DNA. The <I>Pa</I>FAN1 structure provides insights into how FAN1 integrates with the FA complex to participate in ICL repair.</P><P>Fanconi anemia (FA) is an autosomal recessive genetic disorder caused by defects in any of 15 FA genes responsible for processing DNA interstrand cross-links (ICLs). The ultimate outcome of the FA pathway is resolution of cross-links, which requires structure-selective nucleases. FA-associated nuclease 1 (FAN1) is believed to be recruited to lesions by a monoubiquitinated FANCI–FANCD2 (ID) complex and participates in ICL repair. Here, we determined the crystal structure of <I>Pseudomonas aeruginosa</I> FAN1 (<I>Pa</I>FAN1) lacking the UBZ (ubiquitin-binding zinc) domain in complex with 5′ flap DNA. All four domains of the right-hand-shaped <I>Pa</I>FAN1 are involved in DNA recognition, with each domain playing a specific role in bending DNA at the nick. The six-helix bundle that binds the junction connects to the catalytic viral replication and repair (VRR) nuclease (VRR nuc) domain, enabling FAN1 to incise the scissile phosphate a few bases distant from the junction. The six-helix bundle also inhibits the cleavage of intact Holliday junctions. <I>Pa</I>FAN1 shares several conserved features with other flap structure-selective nucleases despite structural differences. A clamping motion of the domains around the wedge helix, which acts as a pivot, facilitates nucleolytic cleavage. The <I>Pa</I>FAN1 structure provides insights into how archaeal Holliday junction resolvases evolved to incise 5′ flap substrates and how FAN1 integrates with the FA complex to participate in ICL repair.</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.

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>

B20 결정구조와 MnGe와 MnSi의 전자구조 및 자기적 특성

정태성,Jeong, Tae Seong 한국재료학회 2019 한국재료학회지 Vol.29 No.8

The magnetic properties and electronic structures of the B20 crystal structure MnGe and MnSi were investigated using the density functional theory with local density approximation. The low symmetry of the B20 crystal structure plays a very important role to make electromagnetic characteristics of these materials. The important result of the calculations is that it can be observed the appearance of a pair of gaps in the density of states near the Fermi level in both compounds. These features are results from d-band splitting by the low symmetry of the crystal field from B20 crystal structure. It can be seen that there is half-metallic characteristics from the density of states in both compounds. The calculation shows that the value of magnetic moment of MnGe is 5 times bigger than that of MnSi even though they have same crystal structure. The electronic structures of paramagnetic case have a very narrow indirect gap just above the Fermi level in both compounds. These gaps acquire some significance in establishing the stability of the ferromagnetic states within the local density approximation. Calculation shows that the Mn 3d character dominates the density of states near the Fermi level in both materials.

탄소 결정의 에너지 준위를 결정하는 고처리량 절차

안재석 한국물리학회 2018 새물리 Vol.68 No.3

To predict a new material with exotic physical properties, we introduce a new theoretical procedure for synthesizing an arbitrary crystal structure by filling the Wyckoff positions of a spacegroup. All the potential crystal structures of a given spacegroup are synthesized with the following three steps: First of all, independent sets of Wyckoff positions are generated. Secondly, the degrees of freedom in the generated sets are pre-optimized using the classical molecular dynamics method. Finally, the crystal structures are further refined using an ab-initio quantum mechanical calculation. We synthesized and compared the crystal structures and the energy levels of carbon crystals composed of less than 16 carbon atoms by using the procedure to generate and refine more than six thousands crystal structures. The utility of our method in predicting an extensive variety of carbon structures, including most of known ones, is demonstrated. 특이한 물성을 갖는 신물질을 예측하기 위하여 주어진 공간군 내의 위코프 (Wyckoff) 자리를 채움을 통해 임의의 결정 구조를 생성하는 이론적 절차를 소개한다. 각각의 공간군마다 다음의 3단계로 모든 가능한 결정 구조를 생성한다. 첫째로, 독립적인 위코프 자리 집합을 생성한다. 둘째, 생성된 집합 내의 자유도를 고전 분자 동역학 방법으로 일차적으로 최적화한다. 마지막으로, 순이론적 양자역학 계산을 통해 결정 구조를 최적화한다. 이를 총 16개 이하의 탄소 원자로 구성된 결정 구조에 적용하여 총 6000개 이상의 결정구조를 정제하였고 그 에너지 준위를 비교하였다. 이 절차의 효용성은 이미 알려진 구조를 포함하여 광범위하게 다양한 탄소의 결정구조가 예측되는 데에서 증명된다.

The Crystal Structure of One Natural Compound Cyclo-(1,10-Docandiamino-11,20-Docanedioic) Amide (1,12-Diazacyclodocosane-2,11-Dione)

Wei, Wan-Xing,Pan, Yuan-Jiang Korean Chemical Society 2002 Bulletin of the Korean Chemical Society Vol.23 No.11

1,12-diazacyclodocosane-2,11-dione was first isolated from a plant Phyllanthus niruri Linn. Its structure has been determined by means of spectroscopy methods and X-ray crystallography. Two peptide groups in the big ring (lactam) are the main factors influencing intermolecular contacts. The hydrogen-bond interaction of these hydrophilic groups is observed in the crystal structure. Meanwhile, C-H···O hydrogen bonds in molecules contribute to the formation of the whole crystal. These two kinds of hydrogen-bond form six- member rings among molecules. This compound crystallizes in the triclinic space group P-1 with a= 9.588(1) $\AA$, b= $9.850(1)\AA$, c = $11.810(1)\AA$, $\alpha=$ 68.18(1)$^{\circ}C$ , $\beta=$ 84.98(1), $\gamma$ = 86.03(1)$^{\circ}C$ , V = $1030.66(17)\AA3$ , Z = 2. A disorder of five-member carbon chain in the whole ring is observed in the title compound. The bond angle 105.8(4) is determined for a extreme configuration C(14)-C(15)-C(16), and 117.7(10) for another extreme configuration C(14')-C(15')-C(16'). In this crystal, two molecules are tied each other by short intermolecular hydrogen bonds, the oxygen atom being tied by hydrogen bond to nitrogen atom of another two molecules. The NMR and IR spectral data coincides to the structure of the compound.