Faculty Profiles - SAKIDA Shinichi

MISC - SAKIDA Shinichi

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Thermal properties and structures of chlorocadmate, bromocadmate, and bromochlorocadmate glasses

S Sakida, H Nakata, Y Kawamoto

SOLID STATE COMMUNICATIONS 127 ( 6 ) 447 - 452 2003.8

Language：English Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Glass transition temperatures (T-g), crystallization temperatures (T-x), and Cd-113 magic-angle spinning (MAS) NNIR spectra of the chlorocadmate, bromocadmate, and bromochlorocadmate glasses and the CdCl2, CdBrCl, and CdBr2 crystals have been measured. The T-g and T-x, and thermal stabilities (T-x - T-g) decreased with increasing Br-content. No enhancement of (T-x - T-g) of bromochlorocadmate glasses by anion-mixing was observed. The CdCl2 and CdBr2 crystals gave the isotropic chemical shifts of 183 and - 24 ppm, which are assigned to the CdCl6 and CdBr6 octahedra, respectively. The isotropic chemical shifts of CdBrCl crystal (186, 166, 135, 101, 63, 25 and -21 ppm) were assigned to CdBrnCl(6-n) (n = 0-6) octahedra, respectively. It was found that the Br and Cl atoms in CdBrCl randomly occupy chlorine sites in the CdCl2 structure. The Cd-113 MAS NMR spectra revealed that the chlorocadmate, bromocadmate, and bromochlorocadmate glasses are composed of the CdCl6, CdBr6 and CdBrnCl(6-n) octahedra (n = 0-6), respectively, and that the Cd2+ in all the bromochlorocadmate glasses was more preferentially bonded to Br- than Cl-. The relationship between the thermal properties and the anion coordination environments around Cd2+ in these glasses is discussed. (C) 2003 Elsevier Ltd. All rights reserved.

DOI： 10.1016/S0038-1098(03)00447-2

カドミウム系塩化物、カドミウム系臭化物、カドミウム系臭化塩化物ガラスの熱的性質および構造

崎田真一

岡山大学大学院ベンチャー・ビジネス・ラボラトリー研究年報 2003

Cu-63 magic angle spinning (MAS) nuclear magnetic resonance (NMR) study of CuX crystals (X = Cl, Br, and I) and CuX-based glasses (X = Cl, Br, and I)

S Sakida, N Kato, Y Kawamoto

MATERIALS RESEARCH BULLETIN 37 ( 14 ) 2263 - 2274 2002.11

Language：English Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Cu-63 MAS NMR spectra of CuX crystals (X = Cl, Br, and I) and CuX-based glasses (X = Cl, Br, and I) have been measured. The CuCl and CuI crystals gave the isotropic chemical shift values around 0 ppm, and the CuBr crystal, around -55 ppm. The peak positions of the chlorocuprate(I), bromocuprate(I), and iodocuprate(I) glasses were very close to those of the CuX crystals, respectively. This result indicates that these glasses mainly consist of CuX4 tetrahedra (X = Cl, Br, and I). The halogen coordination environments around Cu+ in bromochlorocuprate(I) glasses were dependent on the kind of modifying cation and the Br-/(Cl- + Br-) ratio. The bromochlorocuprate(I) glasses were mainly composed of CuClmBr4-m or CuClnBr4-n tetrahedra (m = 0, 1, 2, and 4; n = 0, 1, and 4). (C) 2002 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0025-5408(02)00977-7

Cd-113 MAS and static NMR study of halogenocadmate crystals

S Sakida, Y Kawamoto

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS 63 ( 1 ) 151 - 161 2002.1

Language：English Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Cd-113 magic-angle spinning (MAS) and static NMR spectra are measured using 23 kinds of halogenocadmate crystals with known structures to determine the isotropic chemical shifts (delta (iso)), chemical shift anisotropies (Delta delta), and asymmetry parameters eta and then to discuss the relationship among these NMR parameters and the halide-anion co-ordination environments around Cd2+. The delta (iso(MAS)) values of halide-anion co-ordination polyhedra of Cd2+ largely change with the kind of halide-anion and the halide-anion co-ordination number, The \ Delta delta \ and eta in halogenocadmate crystals is largely dependent on the structure type of crystal, but is independent of the halide-anion co-ordination number of Cd2+. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0022-3697(01)00091-9

113Cd MAS NMR分光法によるカドミウム系臭化物ガラスおよびヨウ化物ガラスの構造研究

崎田真一, 河本洋二

神戸大学ベンチャー・ビジネス・ラボラトリー年報 2002

113Cd MAS NMR study on halogen coordination around Cd2+ in bromocadmate and iodocadmate glasses

S. Sakida, M. Shojiya, Y. Kawamoto

Phys. Chem. Glasses 2002

Structure study of bromocadmate and iodocadmate glasses by Cd-113 MAS NMR spectroscopy

S Sakida, Y Kawamoto

JOURNAL OF NON-CRYSTALLINE SOLIDS 290 ( 1 ) 15 - 19 2001.9

Language：English Publisher：ELSEVIER SCIENCE BV

(LCd)-Cd-113 magic-angle spinning (MAS) NMR spectra have been measured for glasses of 50.0CdBr(2) . xKBr . xCsBr . (50.0-2x)BaBr2 (x = 17.5 and 20.0), 40CdI(2) . 40KI . 20CsI, 50CdI(2) . gamma KI . (50-gamma )CsI (gamma = 10, 20, and 30), 60CdI(2) . 10KI . 30CsI, and (60-z)CdI2 . 40CsI . zBaI(2) (z = 0, 5 and 10) in mol% to reveal the anion co-ordination environments around Cd2+ in the glasses. The bromocadmate and iodocadmate glasses gave isotropic chemical shift values of -27 ppm and 78 similar to 121 ppm, respectively, indicating that the former and the latter glasses consist of CdBr6 octahedra and CdI4 tetrahedra, respectively. Moreover, the octahedral anion co-ordination around Cd2+ in the bromocadmate glasses has higher symmetry than that in the chlorocadmate glasses, and the iodine co-ordination environment around Cd2+ in the iodocadmate glasses is dependent on the CdI2 content, but is independent of the kind of glass-modifying cation. (C) 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-3093(01)00729-3

High-pressure densification of fluoride, GeS2 and silicate glasses

Y Kawamoto, K Miyauchi, M Shojiya, S Sakida, N Kitamura

JOURNAL OF NON-CRYSTALLINE SOLIDS 284 ( 1-3 ) 128 - 133 2001.5

Language：English Publisher：ELSEVIER SCIENCE BV

Densification of glasses having different chemical-bond properties and also different structures have been examined by treating ionic ZrF4-based Buoride glasses, mixed ionic and covalent SiO2-based oxide glasses, and a covalent GeS2 sulfide glass at temperatures of about three-quarters of their respective glass-transition temperatures under pressures up to 9 GPa. The densities of GeS2 glass and silicate glasses of SiO2 contents > 50 mol% increased with increasing applied pressure. In ZrF4-based glasses and silicate glasses with SiO2 contents < 50 mol%. on the other hand, the densities increased until an applied pressure around 3 GPa. the maximum densities were measured at pressures around 3 GPa, and then decreased with increasing pressure. The pressure dependences of permanent densification observed in the latter glasses are a permanent densification that has not been reported to our knowledge. (C) 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-3093(01)00391-X

Cd-113 MAS NMR study of several crystalline fluorides and chlorides containing Cd2+ and 50CdF(2) center dot 30NaCl center dot (20-x) BaF2 center dot xBaCl(2) glasses

S Sakida, M Shojiya, Y Kawamoto

JOURNAL OF NON-CRYSTALLINE SOLIDS 284 ( 1-3 ) 22 - 26 2001.5

Language：English Publisher：ELSEVIER SCIENCE BV

Cd-113 magic-angle spinning nuclear magnetic resonance spectra of crystalline CdF2, KCdF3 and CdCl2 with known crystal structures and vitreous 50CdF(2). 30NaCl . (20 - x)BaF2. xBaCl(2) in mol% (x : 0, 5, 10, 15 and 20) were measured to reveal the anion-coordination environments around Cd2+ in the glasses. The isotropic chemical shifts, delta (iso) of the CdF2, KCdF3 and CdCl2 crystals locate around -226, -105 and 183 ppm, being assigned to the CdF8,CdF6, and CdCl6 polyhedra, respectively. From an analysis of the Cd-113 magic-angle spinning nuclear magnetic resonance spectra of the glasses we deduced that CdFmCln polyhedra (m not equal 0 and n not equal 0) which have not been found in crystalline compounds are present in the glasses. The peak positions and the full widths at half maxima (FWHM) in the glasses increased as BaF2 was replaced by BaCl2. This increase implies that the number of Cl- bonded to Cd2+ increases with increasing BaCl2 content and also that a variety of anion-coordination environments around Cd2+ are more distributed with increasing BaCl2-content. (C) 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-3093(01)00374-X

125Te, 27Al, and 71Ga NMR Study of M2O3-TeO2 (M = Al and Ga) Glasses

Shinichi Sakida, Satoshi Hayakawa, Toshinobu Yoko

Journal of the American Ceramic Society 84 ( 4 ) 836 - 842 2001

Language：English Publisher：American Ceramic Society

The structures of M2O3-TeO2 (M = Al and Ga) glasses have been investigated by means of 125Te, 27Al, and 71Ga NMR spectroscopies. The structural units of respective cations in M2O3-TeO2 glasses were quantitatively analyzed. The fractions of TeO4 trigonal hipyramid. AlO6 and GaO6 octahedra decreased and those of TeO3 trigonal pyramid, AlO4, AlO5, and GaO4 polyhedra increased with increasing M2O3 content. Based on the local structures around Te, Al, and Ga atoms, the structure models of M2O3-TeO2 glasses were proposed.

DOI： 10.1111/j.1151-2916.2001.tb00749.x

AlF3-BaF2-BaCl2-CaF2-YF3-EuF3系ガラス中のAl3+周辺のアニオン配位に関する27Al MAS NMR研究

崎田, 真一, 河本, 洋二

神戸大学ベンチャー・ビジネス・ラボラトリー年報 2001

Al-27 MAS NMR study on anion coordination around Al3+ in AlF3-BaF2-BaCl2-CaF2-YF3-EuF3 glasses

S Sakida, M Shojiya, Y Kawamoto

JOURNAL OF FLUORINE CHEMISTRY 106 ( 2 ) 127 - 131 2000.12

Language：English Publisher：ELSEVIER SCIENCE SA

Al-27 MAS NMR spectra of 12 fluoroaluminate crystals with known crystal structures and 40AlF(3). (20-x)BaF2. xBaCl(2). 20CaF(2). 17YF(3). 3EuF(3). glasses (x = 0, 3, 6, 9 and 12) in mol% were measured to examine the anion coordination environments around Al3+ in the glasses. All the glasses gave NMR spectra with very similar line profiles, indicating that the anion coordination environments around Al3+ are almost the same, and that only F- bonds to Al3+ regardless of the substitution of Cl for F. A comparison of the isotropic chemical shift values and the line profiles between glasses and fluoroaluminate crystals concludes that only AlF6 octahedra are present in the glasses and that these AlF6 octahedra mainly build up chains and/or rings by sharing the two corners in cis-configuration. Moreover, fairly sharp and symmetric line-profiles in the glasses suggest considerably high symmetry in the F--coordination around Al3+. (C) 2000 Elsevier Science S.A. All rights reserved.

Cd-113 MAS NMR study of cadmium halides and their salts

S Sakida, Y Kawamoto

CHEMISTRY LETTERS ( 9 ) 1046 - 1047 2000.9

Language：English Publisher：CHEMICAL SOC JAPAN

Cd-113 magic-angle spinning (MAS) NMR spectra have been measured of twenty-three kinds of Cd2+-containing halide crystals with known structures to determine the isotropic chemical shifts delta(iso). The delta(iso) values of halogen coordination polyhedra largely changed with the kind and the coordination number of halogen. The relationship between the delta(iso) values and the halogen coordination environments around Cd2+ was revealed.

DOI： 10.1246/cl.2000.1046

Permanent densification behavior and Si-29 MAS NMR of SiO2-K2O-CaO-SrO glasses

S Sakida, K Miyauchi, Y Kawamoto, N Kitamura

JOURNAL OF NON-CRYSTALLINE SOLIDS 271 ( 1-2 ) 64 - 72 2000.6

Language：English Publisher：ELSEVIER SCIENCE BV

In permanent densification of xSiO(2). 0.4(100 - x)K2O . 0.4(100 - x)CaO . 0.2(100 - x)SrO glasses (x = 41.2-66.7) in mol% by the 3 and 6 GPa high-pressure treatments a peculiar behavior was found in the glasses of x below 50 mol%. The skeleton structures composed of SiO4 units in the glasses were investigated on the undensified and densified glasses by means of Si-29 magic angle spinning (MAS) NMR spectroscopy. From the peak deconvolution of MAS NMR spectra the Q(n) fractions of SiO4 structural-units, where n (n = 0-4) means the number of bridging oxygen, were examined. At first, the skeleton structures in the undensified glasses are clarified. Then the skeleton structures of the densified glasses are discussed in comparison with those of the undensified glasses, Irrespective of the x value, the fractions of Q(n) of small n-values increased with an increase in the applied pressure, indicating that some of the Si-O-Si bonds are broken under the applied pressure and the skeleton structures were kept even after a release of the applied pressure. It is concluded that other causes should be considered as the origin of the present peculiar behavior, (C) 2000 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-3093(00)00090-9

X-ray diffraction study of MO-TeO2 (M=Zn and Ba) glasses

S Sakida, J Jin, T Yoko

PHYSICS AND CHEMISTRY OF GLASSES 41 ( 2 ) 65 - 70 2000.4

Language：English Publisher：SOC GLASS TECHNOLOGY

Structures of MO-TeO2 (M=Zn and Ba) glasses have been investigated by x-ray diffraction analysis. Local environments around Zn and Ba atoms weve examined in terms of the difference RDF curve, Delta RDF, which was obtained by subtracting the RDF curie of ZnO-Teo(2) glass from that of BaO-TeO2 glass at the same composition. Coordination numbers of Zn and Ba were estimated by the pair function curve fitting with the Delta RDF curves The coordination number of Zn atoms (NZn-O) decreased from 5.3 to 3.9 as ZnO content increased from 10 to 40 mol% Coordination numbers of Ba atoms (NBa-O) up to 35 mol% BaO were 6.1-6.4 independent of BaO content. N-BA (O) decreased over 35 mol% BaO and was 5.6 at 40 mol % BaO On the basis of the local structures around Zn and Ba atoms revealed in this work and the one around Te atoms derived from the previous (125) Te static NMR study: the detailed structure models of MO TeO2 (M=Zn and Ba) glasses were proposed.

Te-125 and V-51 static NMR study of V2O5-TeO2 glasses

S Sakida, S Hayakawa, T Yoko

JOURNAL OF PHYSICS-CONDENSED MATTER 12 ( 12 ) 2579 - 2595 2000.3

Language：English Publisher：IOP PUBLISHING LTD

The structures of V2O5-TeO2 glasses are investigated by means of Te-125 and V-51 static NMR spectroscopies and the local structures around the Te and V atoms are discussed in detail from the respective NMR spectra. The fraction of TeO3 trigonal pyramids increases and that of TeO4 trigonal bipyramids decreases with increasing V2O5 content. The structures of V2O5-TeO2 glasses are quite different from those of tellurite glasses containing network-modifying oxides. The fraction of VO4 tetrahedra increases and that of VO5 trigonal bipyramids decreases with increasing V2O5 content. Both chains consisting of tellurite structural units and those consisting of vanadate structural units contribute to the formation of the glass network in V2O5-TeO2 glasses.

DOI： 10.1088/0953-8984/12/12/302

The local structure of Sm-doped aluminosilicate glasses prepared by sol-gel method

JS Jin, S Sakida, T Yoko, M Nogami

JOURNAL OF NON-CRYSTALLINE SOLIDS 262 ( 1-3 ) 183 - 190 2000.2

Language：English Publisher：ELSEVIER SCIENCE BV

The local structures of Sm and Al in Sm-doped aluminosilicate glasses prepared by the sol-gel method were investigated by using Al-27 MAS NMR spectroscopy and X-ray radial distribution function (RDF) analysis. It is found that at low alumina content (1 mol%). the glass network consists of SiO4 and AlO6 structural units. At higher alumina content, AlO4 and AlO6 structural units coexist in the glasses. It is considered that the formation of AlO4 results in enhancement of the dispersion of Sm ions in these glasses. The average coordination number of Sm in a 10Al(2)O(3). 90SiO(2). 1Sm(2)O(3) glass slightly increased from 7.1 to 8.5 after heat-treatment in reducing atmosphere. The role of Al ions in dispersing Sm ions in a glass matrix is discussed. (C) 2000 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-3093(99)00696-1

Cd-113 magic angle spinning NMR study of crystalline CdF2, KCdF3 and CdCl2 and vitreous CdX2-NaX-BaX2 (X = F and/or Cl)

S Sakida, M Shojiya, Y Kawamoto

SOLID STATE COMMUNICATIONS 115 ( 10 ) 553 - 558 2000

Language：English Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Cd-113 magic-angle spinning (MAS) NMR spectra of crystalline CdF2, KCdF3 and CdCl2 and vitreous 50CdF(2). 30NaF . 20BaF(2), 50CdF(2). 30NaCl .(20 - x)BaF2. xBaCl(2) (x = 0, 5, 10, 15 and 20) and 50CdCl(2). 15NaCl . 35BaCl(2) in mol% were measured so as to reveal the anion coordination environments around Cd2+ in the glasses. The CdF2, KCdF3 and CdCl2 crystals gave the isotropic chemical shifts of about -226, -105 and 183 ppm, which are assigned to the CdF8, CdF6 and CdCl6 polyhedra, respectively. The Cd-113 MAS NMR spectrum of 50CdF(2). 30NaF . 20BaF(2) glass enabled us to estimate quantitatively the fractions of CdF6, CdF7 and CdF8 polyhedra. The Cd-113 MAS NMR spectra revealed that the 50CdCl(2). 15NaCl . 35BaCl(2) glass consists of CdCl6 octahedra and that the 50CdF(2). 30NaCl .(20 - x)BaF2. xBaCl(2) glasses consist of CdF6-pClp, CdF7-qClq and CdF8 polyhedra (p = 0-6 and q = 0-5). The peak position and full-width-at-half-maximum values in the 50CdF(2). 30NaCl .(20 - x)BaF2. xBaCl(2) glasses increased as BaF2 was substituted for BaCl2. This implies that the substitution of BaCl2 for BaF2 results in an increase in the number of Cl- bonded to Cd2+ and the occurrence of various anion-coordination environments around Cd2+. (C) 2000 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0038-1098(00)00223-4

CdF2, KCdF3, CdCl2結晶、CdX2-NaX-BaX2 (X = F and/or Cl)ガラスの113Cd MAS NMR研究

崎田, 真一, 河本, 洋二

神戸大学ベンチャー・ビジネス・ラボラトリー年報 2000

Part 2. Te-125 NMR study of M2O-TeO2 (M = Li, Na, K, Rb and Cs) glasses

S Sakida, S Hayakawa, T Yoko

JOURNAL OF NON-CRYSTALLINE SOLIDS 243 ( 1 ) 13 - 25 1999.1

Language：English Publisher：ELSEVIER SCIENCE BV

The structure of TeO2 and M2O-TeO2 (M = Li, Na, K, Rb and Cs) glasses has been investigated by means of Te-125 static and magic-angle spinning (MAS) NMR spectroscopies. On the basis of the relationship between the local structures around Te atoms and the NMR parameters obtained by Te-125 NMR spectra of various tellurite crystals, the local structures around Te atoms in TeO2 and M2O-TeO2 glasses were examined. The spectral simulation of static NMR spectra enabled us to discriminate between TeO3 trigonal pyramid (tp) and TeO4 trigonal bipyramid (tbp) and to estimate the fractions of TeO3 tp (N-3) and TeO4 tbp (N-4) It was concluded that in TeO2 glass TeO4 tbps are connected by sharing their corners as in alpha-TeO2 crystal. N-3 increased and NS decreased with increasing M2O content. On the basis of a previous structural model, the fractions of TeO4 tbp without a non-bridging oxygen (NBO) atom, TeO4 tbp with an NBO atom, and TeO3 tp with two NBO atoms were calculated. A new model which presents the structural change for M2O-TeO2 glasses has been proposed. (C) 1999 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-3093(98)00812-6

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