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21Author    L. A. Zemnukhova, S. I. Kuznetsov, G. A. Fedorishcheva, R. L. DavidovichRequires cookie*
 Title    The Temperature Dependence of 12U23 Sb, 35 C1, 79,81 Br and 127 I NQR Spectra in Complexes Cs 3 Sb 2 X 9 (X = CI, Br, I)  
 Abstract    The 12U23 Sb, 35 C1, 79 81 Br and 127 I NQR Spectra of the complexes Cs 3 Sb 2 X 9 (X = C1, Br, I), prepared from CsX and SbX 3 aqueous solutions, were studied at 77-400 K. Analysis of the^ temperature coeffi-cients of the quadrupole transition frequency (v), quadrupole coupling constant (e 2 Qq zz) and asymme-try parameter of the electric field gradient (q) was carried out. 
  Reference    Z. Naturforsch. 55a, 134—138 (2000); received October 13 1999 
  Published    2000 
  Keywords    Antimony (III), Haloid Complex Compounds, 121J23 Sb, 35 C1, 79 -81 Br, 127 I, NQR Spectra 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0134.pdf 
 Identifier    ZNA-2000-55a-0134 
 Volume    55 
22Author    T. A. Babushkina, K. G. Konopleva, A. L. Tupoleva, N. U. Venskovskii, L. Guibé, M. Gourdji Tb, A. PéneauRequires cookie*
 Title    NQR Investigation of Intercalates and Complexes of Cadmium and Lead Iodides with Pyridine, Aniline, and Piperidine  
 Abstract    I27 I and 14 N NQR have been investigated in two cadmium idodide -pyridine compounds, the inter-calate CdI 2 +5.9 pyridine and the CdI 2 Py 2 complex. In the intercalate, iodine is mainly ionic and nitro-gen like in pure pyridine; in the complex, iodine exhibits 30% covalency while nitrogen, coordinated to the central cadmium atom of the complex, and presents coupling constants e 2 Qq and r\ smaller than in pure pyridine. The difference between the two compounds is also revealed by the thermal coefficient of the quadrupole coupling constants and the relaxation. Results on the other title compounds are also given. 
  Reference    Z. Naturforsch. 55a, 139—144 (2000); received August 25 1999 
  Published    2000 
  Keywords    Cadmium Iodide, Layered Structure, Intercalation, Pyridine, Nitrogen-14 NQR 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0139.pdf 
 Identifier    ZNA-2000-55a-0139 
 Volume    55 
23Author    Gary Wulfsberg, Joyce Robertson, T. A. Babushkina, S. I. Gushchin, Hiromitsu Terao, John PowellRequires cookie*
 Title    Weakly Coordinating Ligands: Nuclear Quadrupole Coupling Constants and Asymmetry Parameters of Iodocarbons Coordinated to Metal Ions  
  Reference    Z. Naturforsch. 55a, 145 (2000) 
  Published    2000 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0145.pdf 
 Identifier    ZNA-2000-55a-0145 
 Volume    55 
24Author    Z. Z. Akselrod, D. V. Filossofov, J. Buša, T. Bušova, O. I. Kochetov, N. A. Lebedev, A. F. Novgorodov, V. N. Pavlov, A. V. Salamatin, E. N. Shirani, V. V. TimkinRequires cookie*
 Title    Cd Time Differential Perturbed Angular Correlation Studies of High Specific Activity m In-Aqueous Solutions  
 Abstract    Time-differential PAC measurements have been made using the high specific activity of 111 In, both in aqueous solutions of the C10~ 4 , NO~ 3 and CP at pH values between 1.0 and 9 and temperatures between 186 and 293 K. 
  Reference    Z. Naturforsch. 55a, 151—154 (2000); received August 23 1999 
  Published    2000 
  Keywords    "'in, m Cd, High Specific Activity, Nuclear Quadrupole Interaction (NQI), Time Differential Perturbed Angular Correlation (TDPAC) 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0151.pdf 
 Identifier    ZNA-2000-55a-0151 
 Volume    55 
25Author    M. Rentería, L. A. Errico, A. G. Bibiloni, K. Freitag, F. G. RequejoRequires cookie*
 Title    PAC Identification of Electric-Nuclear-Quadrupole Interactions in Sm-Sesquioxides  
 Abstract    We present Perturbed Angular Correlation (PAC) results of the electric-nuclear quadrupole interaction at lxl Ta located at the nonequivalent cation sites of cubic C-Sm 2 0 3 and monoclinic B-Sm 2 0 3 free of defects. The application of the empirical Cd/Ta correlation found in binary oxides allowed us to correlate the interactions with each site and to identify the single Sm site populated in 111 In-implanted B-Sm 2 0 3 experiments. The preferential site occupation of Cd and Ta in B-Samaria is discussed in terms of the "chemistry" of the probe-atoms. 
  Reference    Z. Naturforsch. 55a, 155—159 (2000); received August 26 1999 
  Published    2000 
  Keywords    Perturbed-Angular Correlations, Electric-Field Gradients, Sm 2 0 3, Rare-earth Semiconductor and Insulator Oxides, lxl Hf-Impurity Implantation 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0155.pdf 
 Identifier    ZNA-2000-55a-0155 
 Volume    55 
26Author    Z. A. FokinaRequires cookie*
 Title    C1 and 79 Br NQR Spectra and the Secondary Bonding of Chalcogen Halide Complexes  
 Abstract    The 35 C1 and 7y Br NQR spectra of chalcogen halide complexes of aluminium, gallium, titanium, zir-conium, hafnium, niobium, tantalum, molybdenum, tungsten, rhenium, iron, ruthenium, osmium, irid-ium, rhodium, platinum, palladium and gold are discussed. Three structure types of these complexes have been distinguished by X-ray structure analysis: type I with AX 2 ligand and [MX"A m ] coordination polyhedron; type II with AX 3 ligand and [MX" +m ] coor-dination polyhedron; type III, dimeric complexes with M-X-M bridge (where X = C1, Br and A = S, Se, Te). The formation of secondary M-X-A or M-X-M bonds is characteristic of most structures. The spec-tra were interpreted by a Townes-Dailey approximation with allowance for the electronic configuration of the metal, mutual influence of ligands and structure features of complexes. Systematic investigation of a big series of chalcogen halide complexes-analogues allowed the following changes in -CI and ™Br NQR frequencies on secondary bonding to be established for intraligand halogen atoms: A decrease in frequency for type I complexes and an increase in frequency for type II complexes; for halogen atoms in the coordination polyhedron: a decrease in frequency for p metals and transition metals with d>6, and an increase in frequency for metals with d< 6. 
  Reference    Z. Naturforsch. 55a, 160—166 (2000); received November 5 1999 
  Published    2000 
  Keywords    Electronic Configuration, Mutual Influence of Ligands, Coordination Polyhedron, Peripheral Polyhedron 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0160.pdf 
 Identifier    ZNA-2000-55a-0160 
 Volume    55 
27Author    Masao Hashimoto, Shinichi Hashimoto, Hiromitsu Terao, Masayuki Kuma, Haruo Niki, Hiroyuki InoRequires cookie*
 Title    Crystal Structure and Phase Transition of 4-Aminopyridinium Tetrabromoantimonate(III) as Studied by Bromine and Antimony NQR, Proton NMR, and Single Crystal X-Ray Diffraction  
 Abstract    The crystal structure of the room temperature phase (RTP) of the title compound was determined at 297 K (monoclinic, space group C2/c, a = 1384.2(2), b = 1377.8(3), c = 755.5(2) pm, ß = 121.58(1)°). A complicated disorder was found for the cation. A phase transition from the low-temperature phase (LTP) to the RTP was found at (224 ±1) K (T c). The 'H NMR spectra showed a sharp motional narrowing at ca. T=T C , indicating the occurrence of a reorientational motion of the cation in the RTP in accord with the disorder. It was found that another reorientational motion is excited in the LTP. Four 81 Br NQR lines (132.71, 115.38, 61.54 and 59.31 MHz at 77 K) and two Sb NQR lines (53.78 and 33.76 MHz at 77 K) were found in the LTP, while a single 81 Br NQR line was observed at T> 276 K (ca. 121.80 MHz at 300 K). Crystal dynamics are discussed on the basis of the temperature dependence of the NQR, *H NMR line width, and 'H NMR Tj. 
  Reference    Z. Naturforsch. 55a, 167—172 (2000); received August 24 1999 
  Published    2000 
  Keywords    4-NH 2 PyHSbBr 4, Crystal Structure, Phase Transition, NQR, 'H NMR 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0167.pdf 
 Identifier    ZNA-2000-55a-0167 
 Volume    55 
28Author    Takahiro Iijima, Motohiro Mizuno, Masahiko SuharaRequires cookie*
 Title    H NMR Study of Molecular and Electron Spin Dynamics in Paramagnetic [Co(H 2 0) 6 ][SiF 6 ]  
 Abstract    The temperature dependences of 2 H NMR spectra and the spin-lattice relaxation time T\ were measured for [Co(H20)f,][SiF6]. The variation of the spectrum above room temperature can be explained by the reorientation of [Co(H20)fi] 2+ about the C3 axis. The activation energy E a and the jumping rate at infinite temperature fco for the three site jump of [Co(H20)6] 2+ were obtained as 82 kJmol -1 and 2x 10 17 s~ 1 from the spectral simulation. Below room temperature, the spectral line shape was dominated by the 180° flip of the water molecule. The minimum of T\ caused by the 180° flip of the water molecule was observed at ca. 260 K. The jumping rate of the 180° flip of the water molecule was estimated from the 2 H NMR T\ and the spectral simulation. E* = 38 kJmol -1 and fco = 6x 10 l5 s -1 for the 180° flip of the water molecule were obtained from T\. 
  Reference    Z. Naturforsch. 55a, 173—177 (2000); received August 23 1999 
  Published    2000 
  Keywords    Phase Transition, 2 H NMR, Nuclear Quadrupole Interaction, Paramagnetic Shift, Molecular Dynamics 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0173.pdf 
 Identifier    ZNA-2000-55a-0173 
 Volume    55 
29Author    Motohiro Mizuno, Takahiro Iijima, Kengo Orii, Masahiko SuharaRequires cookie*
 Title    Water Molecular Motion and Hydrogen Bond in Paramagnetic [Cu(H 2 0) 6 ][PtCl 6 ] as Studied by Single Crystal 2 H NMR  
 Abstract    The temperature and angular dependences of the 2 H NMR spectrum were measured for single crystal [Cu(H 2 0) 6 ] [PtCl 6 ]. (e 2 Qq/h, r?) = (132 kHz, 0.72) were obtained for the D nucleus averaged by the fast 180° flip of the water molecule at 297 K. D,(236 kHz, 0.10) and D 2 (246 kHz, 0.09) were obtained for two unequal D nuclei of the water molecule at 133 K. Below T c , at least three nonequivalent waters were found to exist. The jumping rate for the 180° flip of the water molecule (k) was obtained from the simulation of 2 H NMR spectra at //o||[l 11] direction. The activation energy E d and the jumping rate at infinite temperature were estimated from the temperature dependence of k to be 24kJmol _1 and 1 x 10 13 s -1 . 
  Reference    Z. Naturforsch. 55a, 178—182 (2000); received August 23 1999 
  Published    2000 
  Keywords    Phase Transition, 2 H NMR, Nuclear Quadrupole Interaction, Paramagnetic Shift, Molecular Dynamics 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0178.pdf 
 Identifier    ZNA-2000-55a-0178 
 Volume    55 
30Author    Hiroki Fujimori, Tetsuo AsajiRequires cookie*
 Title    CI NQR in Glassy Crystal of 2-chlorothiophene  
 Abstract    Stable crystalline 2-chlorothiophene has two glass transitions at 164 and 186 K. 35 CI NQR measurements were carried out between 77 and 200 K. Two NQR signals with full widths of about 100 kHz at half maximum were observed in this temperature range. The spin-lattice relaxation times Ti were measured at the two peak frequencies. The activation energy obtained from the results of the T\ measurements showed a fairly good agreement with those estimated from calorimetric measurements. 
  Reference    Z. Naturforsch. 55a, 183—185 (2000); received October 13 1999 
  Published    2000 
  Keywords    NQR, 2-chlorothiophene, Glassy Crystal, Glass Transition 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0183.pdf 
 Identifier    ZNA-2000-55a-0183 
 Volume    55 
31Author    M. I. Oshtrakh, V. A. Semionkin, O. B. Milder, A. B. Livshits, A. A. KozlovRequires cookie*
 Title    Quadrupole Splitting and Paramagnetic Iron Core Structure in Iron-Dextran Complexes: A Mössbauer Effect Study  
 Abstract    The pharmaceutical^ important iron-dextran complexes (ferritin models) were studied by Mössbauer spectroscopy in frozen solution at 87 K and in lyophilized form at 297 and 87 K. The quadrupole splittings of the lyophilized forms of iron-dextran complexes measured at 297 and 87 K were slightly different. The quadrupole splittings of several complexes in lyophilized form and frozen solutions measured at 87 K were also different. Slight differences in the quadrupole split-ting were found for various iron-dextran complexes. Mössbauer spectra of iron-dextran complexes were better fitted using two quadrupole split doublets. Slight differences in the corresponding quadrupole splittings and doublet ratios were observed for various complexes. 
  Reference    Z. Naturforsch. 55a, 186—192 (2000); received September 11 1999 
  Published    2000 
  Keywords    Iron-dextran Complexes, Mössbauer Spectroscopy, Paramagnetic Iron Core, Quadrupole Splitting 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0186.pdf 
 Identifier    ZNA-2000-55a-0186 
 Volume    55 
32Author    M. I. Oshtrakh, O. B. Milder, V. A. Semionkin, A. L. Berkovsky, M. A. Azhigirova, E. P. VyazovaRequires cookie*
 Title    Variation of Quadrupole Splitting in Modified Oxyhemoglobin: A Mössbauer Effect Study  
 Abstract    Human adult hemoglobin modified by both pyridoxal-5'-phosphate and glutaraldehyde in the oxy-form was studied by Mössbauer spectroscopy. Mössbauer spectra were measured at 87 and 295 K (hemoglobin in lyophilized form) and at 87 K (hemoglobin in frozen solution). The values of the quadrupole splitting for modified oxyhemoglobin were found to be lower then those of oxyhemoglobin without modifications in lyophilized form and frozen solution, respectively. The Mössbauer spectra of modified oxyhemoglobin were also analyzed in terms of the heme iron inequivalence in a-and /3-subunits of the tetramer. Differences of the tendencies of temperature dependencies of quadrupole splitting for modified and non-modified oxyhemoglobin in lyophilized form were shown. 
  Reference    Z. Naturforsch. 55a, 193—198 (2000); received September 11 1999 
  Published    2000 
  Keywords    Hemoglobin, Mössbauer Spectroscopy, Quadrupole Spitting 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0193.pdf 
 Identifier    ZNA-2000-55a-0193 
 Volume    55 
33Author    A. M. Petrosyan, V. M. Burbelo, R. A. Tamazyan, H. A. Karapetyan, R. P. SukiasyanRequires cookie*
 Title    NQR in Alanine and Lysine Iodates Presented at the XVth International Symposium on Nuclear Quadrupole Interactions  
 Abstract    The structure of iodates of a-and /3-alanine (Ala) (2(jß-Ala • HI03) • H20, ß-Ala-2HI03, DL-Ala • HI03 • 2H,0, L-Ala • HI03) and L-lysine (L-Lys) (L-Lys • HI03, L-Lys • 2HIO-,, L-Lys • 3HIO-,, L-Lys • 6HIO-?) have been investigated by means of iodine-127 NQR, IR spectroscopy and X-ray dif-fraction. 
  Reference    Z. Naturforsch. 55a, 199—206 (2000); received October 13 1999 
  Published    2000 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0199.pdf 
 Identifier    ZNA-2000-55a-0199 
 Volume    55 
34Author    Y. M. Seo, S. K. Song, J. PelzpRequires cookie*
 Title    Impurity Effects on the Local Structure in the Mixed Hexachlorometallate (A 2 BC1 6 : A = K, Rb, B = Sn, Re, and Pb) Studied by the Chlorine NQR  
 Abstract    Chlorine NQR was studied for the isostructural hexachlorometallate mixed system. The study shows that Isomorphic hexachlorometallate solid solutions exhibit often impurity induced local structural order because of their relatively clear local site symmetry. This is manifested in the formation of a few satellite lines near the original resonance line and results from the random distribution of impurities on the lattice sites of the corresponding counterpart ions. Using the point charge model and a simple binomial function for the occupation probability of the guest ions on the host lattice sites, the position and the line intensity could be determined, the results of which are in good agreement with the NQR-observation. The temperature region of lattice dynamics in the crystal seems to shift in proportion to the impurity content. This fact explains the gradual change of the transition temperature in the mixed crystal between two starting materials. 
  Reference    Z. Naturforsch. 55a, 207—211 (2000); received August 23 1999 
  Published    2000 
  Keywords    NQR, Hexahalmetallates, Phase Transition, Mixed Crystals 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0207.pdf 
 Identifier    ZNA-2000-55a-0207 
 Volume    55 
35Author    J. Pirnat, Z. Trontelj, Z. Jagličić, K. Lutar, H. BorrmannRequires cookie*
 Title    Arsenic NQR in the Paramagnetic Complex Co(AsF 6 ) 2 -2AsF 3  
 Abstract    Arsenic NQR in Co(AsF 6) 2 .2AsF 3 reveals three lines: one near 122 MHz and two near 50 MHz. Relations of the spectral lines to the structure and to thermal vibrations are discussed. Possible influence of paramagnetic Co is examined. 
  Reference    Z. Naturforsch. 55a, 212—214 (2000); received October 13 1999 
  Published    2000 
  Keywords    Co(AsF 6 ) 2, Complex, NQR, Paramagnet, Crystal Structure 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0212.pdf 
 Identifier    ZNA-2000-55a-0212 
 Volume    55 
36Author    J. Pirnat, Z. Trontelj, J. Lužnik, D. KirinRequires cookie*
 Title    Halogen NQR and the Phase Transition in CH 3 Hg-Halide Family  
 Abstract    The temperature dependence of the 35 C1 NQR line and its relaxation has been measured from 77 K to room temperature. The known displacive phase transition near 162 K is reflected in the change of the slope of the temperature dependence of the quadrupole line, but not so in the chlorine or proton relaxation. The results are discussed in view of the proposed structural changes and thermal vibrations. 
  Reference    Z. Naturforsch. 55a, 215—218 (2000); received October 13 1999 
  Published    2000 
  Keywords    Methylmercury Chloride, NQR, Crystal Structure, Phase Transition, Thermal Vibrations 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0215.pdf 
 Identifier    ZNA-2000-55a-0215 
 Volume    55 
37Author    S. K. Song, Y. M. Park, J. K. Jung, Y. M. Seo, S. H. ChohRequires cookie*
 Title    N NQR Studies of Impurity Effects on the Local Structure of NaN0 2 -based Mixed Systems  
 Abstract    The influence of impurities on the 14 N NQR lineshape of Na 1 _^Ag c N0 2 and [NaN0 2 ],_,-[BN0 3 ]^ (B = Na, K) at room temperature has been investigated. Carrying out spectral analysis in conjunction with classification of the local field inhomogeneities according to the structurally isomorphic, Na]_ x Ag x N0 2 , and anisomorphic [NaNO^.JBNC^b systems, enabled an under-standing of the microscopic nature of impurity-induced local disorder. The iso-and anisomorphic systems reveal their own unique features of the impurity induced local disorder. They are charac-terized by a static, random distribution of impurities in the isomorphic system and a fast motion of the impurity-induced mobile point defects in the anisomorphic system. However, for both systems, neither a change of the 14 N NQR frequency nor a multisplitting of the lines is observed because of the relatively low symmetry. 
  Reference    Z. Naturforsch. 55a, 219—224 (2000); received August 23 1999 
  Published    2000 
  Keywords    NQR, Lineshape, Iso-and Anisomorphic Systems, Local Disorder 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0219.pdf 
 Identifier    ZNA-2000-55a-0219 
 Volume    55 
38Author    Hideta Ishihara, Keizo Horiuchi, ThorstenM. Gesing, Shi-Qi Dou, J.-Christian Buhl, Hiromitsu TeraoRequires cookie*
 Title    I NQR and Crystal Structure Studies of [N(CH 3 ) 4 ] 2 CdI 4  
 Abstract    The temperature dependence of 127 1 NQR and DSC as well as the crystal structure at room temperature of the title compound were determined. This compound shows a first-order phase transition of an order-disorder type at 245 K. Eight 127 I(i^i: m = ±5 <-+ ±|) NQR lines of 79. corresponding eight 127 I(^ 2 : m = ±| <-» • ±|) NQR lines were observed at liquid nitrogen temperature. Three 127 I(^i) NQR lines wfth an intensity ratio of 1:1:2 in the order of decreasing frequency were observed just above the transition point and two NQR lines except for the middle-frequency line disappeared around room temperature. This temperature behavior of NQR lines is very similar to that observed in [N(CH 3)4] 2 Hgl4. Another first-order phase transition takes place at 527 K. The structure of the room-temperature phase was redetermined: orthorhombic, Pnma, Z = 4, a = 1342.8(3), b = 975.7(2), c = 1696.5(3) pm. The NQR result of three lines with an intensity ratio of 1:1:2 is in agreement with this structure. The thermal displacement parameters of atoms in both cations and anions are large. 
  Reference    Z. Naturforsch. 55a, 225—229 (2000); received October 13 1999 
  Published    2000 
  Keywords    NQR, DSC, Crystal Structure, Phase Transition 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0225.pdf 
 Identifier    ZNA-2000-55a-0225 
 Volume    55 
39Author    Hiromitsu Terao, Masao Hashimoto, Shinichi Hashimoto, Yoshihiro FurukawaRequires cookie*
 Title    Studies of Structure and Phase Transition in [C(NH 2 ) 3 ]HgBr 3 and [C(NH 2 ) 3 ]HgI 3 by Means of Halogen NQR, NMR, and Single Crystal X-Ray Diffraction  
 Abstract    The crystal structure of [C(NH 2) 3 ]HgBr 3 was determined at room temperature: monoclinic, space group C2/c, Z = 4, a = 775.0(2), b = 1564.6(2), c = 772.7(2) pm, ß = 109.12(2)°. In the crystal, almost planar HgBr 3 ~ ions are connected via Hg -Br bonds, resulting in single chains of trigonal bipyramidal HgBr 5 units which run along the c direction. [C(NH 2) 3 ]HgI 3 was found to be isomorphous with the bromide at room temperature. The temperature dependence of the halogen NQR frequencies (77 < 77K < ca. 380) and the DTA measurements evidenced no phase transition for the bromide, but a second-order phase transition at (251 ± 1) K (7 tl) and a first-order one at (210 ± 1) K (T C2) for the iodide. The transitions at T C2 are accompanied with strong supercooling and significant superheating. The room temperature phase (RTP) and the intermediate temperature phase (ITP) of the iodide are characterized by two I(m =i/2~3/2) NQR lines which are assigned to the terminal and the bridging I atoms, respectively. There exist three lines in the lowest temperature phase (LTP), indicating that the resonance line of the bridging atom splits into two. The signal intensities of the 127 I (m =i/2—3/2) NQR lines in the LTP decrease with decreasing temperature resulting in no detection below ca. 100 K. The 127 I(m =i/ 2 ~3/2) NQR frequency vs. temperature curves are continuous at T CL , but they are unusual in the LTP. The T X vs. Tcurves of 'H NMR for the bromide and iodide are explainable by the reorientational motions of the cations about their pseudo three-fold axes. The estimated activation energies of the motions are 35.0 kJ/mol for the bromide, and 24.1, 30.1, and 23.0 kJ/mol for the RTP, FTP, and LTP of the iodide, respectively. 
  Reference    Z. Naturforsch. 55a, 230—236 (2000); received August 23 1999 
  Published    2000 
  Keywords    [C(NH 2 ) 3 ]HgX 3, Crystal Structure, Phase Transition, NQR, 'H NMR 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0230.pdf 
 Identifier    ZNA-2000-55a-0230 
 Volume    55 
40Author    P. De, La Presa, K. P. Lieb, M. Uhrmacher, L. ZiegelerRequires cookie*
 Title    Perturbed Angular Correlation Studies in SrTi0 3 Single Crystals  
 Abstract    The quadrupole hyperfine interactions of 11 'Cd/ 111 In probe nuclei in single-crystalline SrTi0 3 perovskite samples were investigated using Perturbed Angular Correlation spectroscopy. Three electric field gradients were detected and their fractions and hyperfine parameters were measured in the temperature range from 26 to 700 K. The fraction / 0 having a vanishing quadrupole frequency, as expected for 111 Cd on substitutional sites in a cubic lattice, starts to develop around 300 K and reaches 100% at 700 K. Two well-defined EFG's having closely lying quadrupole frequencies and asymmetry parameters of cj qi = 49.1(3) Mrad/s, 77, = 0.10(2) and u Q2 = 51.8(3) Mrad/s, r] 2 = 0.12(2), at room temperature, were identified in the temperature range from 250 to 530 K, and their (100) orientation in the lattice was determined. They are associated with electronic defects at the probe atoms. 
  Reference    Z. Naturforsch. 55a, 237—241 (2000); received August 24 1999 
  Published    2000 
  Keywords    Perturbed Angular Correlations, SrTi0 3, Single Crystal, Electronic Defects, Perovskite 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0237.pdf 
 Identifier    ZNA-2000-55a-0237 
 Volume    55 
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