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1998[X]
41Author    J.Mestnik Filho, A. W. Carbonari, E. F. Motta, M. Moralles, R. N. Saxena, M. Olzon-Dionysio, S. D. De SouzaRequires cookie*
 Title    Ionic Size Induced Defects in Lead Titanate-Zirconate Perovskite Studied by TDPAC Method  
 Abstract    Time differential perturbed angular correlation (TDPAC) measurements were carried-out on PbZr 0 8 Ti 0 2 0 3 as a function of temperature. A broad distribution of electric field gradient (EFG) was observed in all cases with a second site for 181 Hf-181 Ta probes in the R3c phase. The results were analyzed in terms of a model which simulates an attraction of the ions by the smaller Ti ions. The EFG was calculated within the point charge approximation, by averaging over a large number of configurations generated by random distribution of the Ti ions in an ensemble of lattice cells. It was verified that the model reproduces qualitatively the broadening of the TDPAC frequencies as well as explains the second component EFG observed experimentally. 
  Reference    Z. Naturforsch. 53a, 318—322 (1998); received October 31 1997 
  Published    1998 
  Keywords    PbZr x Ti 1^3, Perovskites, Crystal Defects, TDPAC Measurements 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0318.pdf 
 Identifier    ZNA-1998-53a-0318 
 Volume    53 
42Author    Pit Schmidt, Torsten Soldner, Wolfgang Tröger, Xinbo Ni, Tilman Butz, Peter BlahaRequires cookie*
 Title    Nuclear Quadrupole Interaction at 187 W(/T) 187 Re in längsten Compounds  
 Abstract    The nuclear quadrupole interaction at l87 W(/T) l87 Re was determined by time differential perturbed angular correlation inWC, WS 2 , WSe 2 , WSi 2 , and CaW0 4 to be (at 300 K): v Q = 335.9(2), 1094.9(1), 1031.6(1), 1131,5(1), and 1085.9(1) MHz, respectively. The asymmetry parameter 77 was zero in all cas-es. For WSe 2 and CaW0 4 the temperature dependence of the nculear quadrupole interaction was deter-mined between 300 K and about 900 K. Ab initio calculations of electric field gradients, using the WIEN95-code, were carried out for WC, WS 2 , WSe 2 , and WSi 2 at W-sites and Re-impurities, and for CaW0 4 at W-sites. Good agreement with experimental data was found. 
  Reference    Z. Naturforsch. 53a, 323—339 (1998); received January 26 1998 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0323.pdf 
 Identifier    ZNA-1998-53a-0323 
 Volume    53 
43Author    Zhu ShengyunRequires cookie*
 Title    Applications of Nuclear Quadrupole Interactions in Materials Research  
 Abstract    The principle of the time differential perturbed angular correlation and distribution technique which measures the nuclear quadrupole interaction is briefly described. Some examples are given to show the possibilities of this technique in microscopic studies of materials. 
  Reference    Z. Naturforsch. 53a, 340—348 (1998); received February 25 1998 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0340.pdf 
 Identifier    ZNA-1998-53a-0340 
 Volume    53 
44Author    P. Wodniecki, A. Kulińska, B. Wodniecka, A. Z. HrynkiewiczRequires cookie*
 Title    Electric Field Gradients at the In Site in Au-In Compounds  
 Abstract    The quadrupole interaction in Au-In compounds of different stoichiometrics was studied with the perturbed angular correlation technique. The electric field gradients at 11 : Cd probes were measured and the temperature dependences of the quadrupole frequencies were determined. A new high temperature phase of Auln above 630 K and a new metastable modification of Au 7 In 3 were found. 
  Reference    Z. Naturforsch. 53a, 349—354 (1998); received October 31 1997 
  Published    1998 
  Keywords    Perturbed Angular Correlations, EFG, Intermetallic Compounds, Au-In System 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0349.pdf 
 Identifier    ZNA-1998-53a-0349 
 Volume    53 
45Author    P. Wodniecki, B. Wodniecka, A. Kulińska, A. Z. HrynkiewiczRequires cookie*
 Title    Electric Quadrupole Interaction at 181 Ta in Isostructural Orthorhombic Cu 8 Hf 3 and Cu 8 Zr 3 Compounds  
 Abstract    The quadrupole interaction of 181 Ta probes in isostructural Cu 8 Hf 3 and Cu 8 Zr 3 intermetallic compounds was studied in the temperature range 24 K -1100 K with the time-differential perturbed angular correlation technique. Two nonaxial electric field gradients corresponding to two nonequiv-alent hafnium or zirconium sites in the investigated structure were found. A linear decrease in the quadrupole interaction frequency with increase of temperature for the 8(d) sites was evidenced, while the v Q (T) dependence for the 4(c) sites is weaker and has a T 312 character. 
  Reference    Z. Naturforsch. 53a, 355—357 (1998); received October 31 1997 
  Published    1998 
  Keywords    Hyperfine Interactions, Perturbed Angular Correlations, EFG, Intermetallic Compounds, Cu-Hf and Cu-Zr Systems 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0355.pdf 
 Identifier    ZNA-1998-53a-0355 
 Volume    53 
46Author    F. Hagelberg, T. P. DasRequires cookie*
 Title    Evaluation of the 57m Fe Quadrupole Moment from Hartree-Fock Calculations  
 Abstract    Two theoretical evaluations of 57m Fe quadrupole moment (0, based on different formalisms, namely the Hartree-Fock theory and the Linearized Augmented Plane Wave method have yielded results differing by a factor of two. In both cases, Q was obtained from experimental quadrupole interaction frequencies through investigation of the Electric Field Gradients at the nuclear site of the 57m Fe probe. It is the purpose of the present work to reexamine the earlier Hartree-Fock approach. In particular, the earlier model is extended through a more realistic description of the environment of Fe in the respective experiments, as well as through inclusion of electron correlation effects. 
  Reference    Z. Naturforsch. 53a, 358—361 (1998); received March 24 1998 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0358.pdf 
 Identifier    ZNA-1998-53a-0358 
 Volume    53 
47Author    Michal Jaszuński, Antonio RizzoRequires cookie*
 Title    Ab initio Study of Nitrogen-14 Nuclear Quadrupole Coupling and NMR Signal Linewidths in Some Azoles  
 Abstract    Ab initio values of Nitrogen l4 N Nuclear Quadrupole Coupling Constants (NQCC's) are calcu-lated for a series of methyl-substituted azoles in the Multiconfigurational SCF (MCSCF) approx-imation. The four triazoles and two tetrazoles studied here are all isoelectronic. This enabled us to use the same level of approximation -basis set and active space -for all the molecules. The computed NQCC's are used to estimate the relative widths of the U N NMR signals, assuming an identical effect of molecular tumbling for all the nuclei in a molecule and neglecting solvent effects. The linewidths for the unsubstituted N atoms are, in agreement with experiment, much larger than for the methyl-substituted N atom. For the 1-methyl-tetrazole we present also the NMR shielding and spin-spin coupling constants and discuss in some more detail the dependence of all calculated NMR properties on the basis set and correlation effects. 
  Reference    Z. Naturforsch. 53a, 362—369 (1998); received December 31 1997 
  Published    1998 
  Keywords    14 N NQCC, Azoles, MCSCF, Ab initio, Electron Correlation 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0362.pdf 
 Identifier    ZNA-1998-53a-0362 
 Volume    53 
48Author    MichaelH. Palmer, JohnA. Blair-FishRequires cookie*
 Title    Halogen Nuclear Quadrupole Coupling Constants in Non-axially symmetric Molecules; Ab initio Calculations, which Include Correlation, Compared with Experiment  
 Abstract    Ab initio determination of the electric field gradient (EFG) tensors at halogen and other centres ena-bled determination of the nuclear quadrupole coupling constants (NQCC) for a diverse set of C 2v , C 3v and other symmetry molecules of general formula MH 2 X 2 and MHX 3 , where the halogen atoms (X) are Cl, Br and I, and the heavy central atoms (M) are C and Si. The study presents results at a standardised level of calculation, triple-zeta in the valence space plus polarisation functions (TZVP) for the equilib-rium geometry stage; all-electron MP2 correlation is included in all these studies. For the bromo and iodo compounds, especially the latter, it is essential to allow core polarisation, by decontraction of the p,d-functions. This is conveniently done by initial optimization of the structure with a partly contract-ed basis, followed by reestablishment of the equilibrium structure with the decontracted basis. The NQCCs, derived from the EFGs, using the 'best' values for the atomic quadruple moments Cl, Br and I, lead to good agreement with the inertial axis (IA) data obtained from microwave spectrosco-py. When the data from the present study is plotted against the values derived from the IA data, obtained by whatever approximations chosen by the MW authors, we obtain a linear regression for the data (85 points) with the slope 1.0365 and intercept -0.1737, with standard errors of 0.0042 and 0.2042, re-spectively; these are statistically identical results irrespective of whether the data is restricted to IA or EFG principal axis (PA) data. Since as in the C 3v MH 3 X compounds studied previously, a close correlation of the microwave spec-tral data with the calculations was observed using the 'best' current values for Q z , there seems no need to postulate that the values of Q Br for both 74 Br and M Br are seriously in error. A scaling downwards of Q z by about 5% for Br and I increases the agreement with experiment, but the contributions of relativ-istic effects are unknown, and could lead to further reassessment. Of the two common assumptions used in MW spectroscopy, to convert from IA to EFG-PA data, ei-ther (a) cylindrical symmetry of the NQCC along the bond direction, or (b) coincidence of the tensor principal element with the bond axis, the latter is found to be a much more realistic approximation. 
  Reference    Z. Naturforsch. 53a, 370—382 (1998); received March 24 1998 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0370.pdf 
 Identifier    ZNA-1998-53a-0370 
 Volume    53 
49Author    MichaelH. Palmer, JohnA. Blair-Fish, Paul Sherwood, MartynF. GuestRequires cookie*
 Title    Halogen Nuclear Quadrupole Coupling Constants: Comparison of ab initio Calculations which include Correlation, with Experiment  
 Abstract    Ab initio determination of the electric field gradient (EFG) tensors at halogen and other centres ena-bled determination of the nuclear quadrupole coupling constants (NQCC) for a diverse set of axially symmetric (C 3l " CD^ and other symmetries) inorganic and organic molecules, where the heavy ele-ments are Cl, Br, and I with C, Si, Ge, and Sn hydrides. The latter elements are in an approximately tet-rahedral environment. The study presents results at a standardised level of calculation, triple-zeta in the valence space (TZV) plus polarisation functions (TZVP) for the equilibrium geometry stage; all-elec-tron MP2 correlation is included in all these studies. f-Orbital exponents were optimised for both Br and I centres in the methanes; the atomic populations of the f-orbital components are very small for the Br-and I-atoms, confirming their role as polarisation functions rather than having any bonding character. The EFG are determined at equilibrium with the TZVP basis set, except Sn and I centres where the ba-sis set is TZV + MP2. For the bromo and iodo compounds, especially the latter, it is essential to allow for core polarisation, by decontraction of the p,d-functions. This is conveniently done by initial optimi-zation of the structure with a partly contracted basis, followed by reestablishment of the equilibrium structure with the decontracted basis. A close correlation of the observed (microwave spectral) data with the calculations was observed, using the 'best' values for the atomic quadrupole moments for Cl, Br, and I; thus there seems no need to postulate that the value of ß Br for 79 Br and Br are in error. The SCF and MP2 wave-functions were converted into localised molecular orbitals by the Boys Method. This al-lowed a study of the differing s/p/d-hybridisation ratios, and the centroid positions, to be compared with the quadrupole coupling constants. The charge distributions for the atoms were converted into local bond dipoles, which in turn are correlated with the electronegativity differences of the bonded atoms. 
  Reference    Z. Naturforsch. 53a, 383—395 (1998); received January 26 1998 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0383.pdf 
 Identifier    ZNA-1998-53a-0383 
 Volume    53 
50Author    K. Sato, H. Akai, T. MinamisonoRequires cookie*
 Title    Ab initio Calculations of Electric Field Gradients for Transition Metal Impurities in TiO z  
 Abstract    We present ab initio calculations of EFGs at impurities in a Ti0 2 crystal. They are directly calculated from the self consistent charge distribution which is determined by the KKR method within the muffin-tin approximation and based on the local density approximation. Impurities in the crystal are simulated by the super-cell method. Considering the charge state of Sc, Ti, Nb, Cd, Ta impurities in the Ti0 2 , the experimental values were well reproduced. The electronic structure of these impurities is discussed by analyzing the calculated density of states. 
  Reference    Z. Naturforsch. 53a, 396—403 (1998); received October 31 1997 
  Published    1998 
  Keywords    Ti0 2, Electric Field Gradient, Transition Metal Impurity, Band-Structure, Charge State 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0396.pdf 
 Identifier    ZNA-1998-53a-0396 
 Volume    53 
51Author    Torsten Soldner, Wolfgang Tröger, Tilman Butz, Peter Blaha, Karlheinz SchwarzRequires cookie*
 Title    Measurement and Calculation of Electric Field Gradients in Hg-Mercaptides  
 Abstract    Electric field gradients (EFG) at Hg were determined in mercury mercaptides Hg(S(CH 2) i CH 3) 2 experimentally for ie {0, 1, 2} using time differential perturbed angular correlation and theoreti-cally for ie {0, 1} with the full potential linearized augmented plane wave code WIEN95. Due to the large unit cells and small hydrogen atoms not full convergence of the plane wave basis set could be reached. Nevertheless, the calculated EFGs agree with experimental values to better than 20%. Furthermore, isolated molecules for i e {0, 1) were investigated theoretically, and strong differences to the values for the crystalline state, especially for the asymmetry parameters rj, were found. 
  Reference    Z. Naturforsch. 53a, 404—410 (1998); received October 31 1997 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0404.pdf 
 Identifier    ZNA-1998-53a-0404 
 Volume    53 
52Author    Torsten Soldner, Wolfgang Tröger, Tilman Butz, Peter Blaha, Karlheinz SchwarzRequires cookie*
 Title    Calculation of Electric Field Gradients in Isolated Molecules Using the FPLAPW-Code WIEN95  
 Abstract    The full potential linearized augmented plane wave method as embodied in the program package WIEN95 was originally developed for crystalline solids and is based on crystal periodicity. The present work demonstrates that it is applicable to isolated molecules with the examples of CdCl 2 , HgF 2 , and HgCl 2 by investigating the required size of artificially enlarged unit cells and by calculating bond dis-tances and vibrational frequencies in excellent agreement with experimental data. The dependence of electric field gradients at Cd and Hg, respectively, on bond angle is investigated. A point charge like be-haviour of energetically low lying states is found, whereas large discrepancies from the point charge model occurred for the energetically high lying valence states. 
  Reference    Z. Naturforsch. 53a, 411—418 (1998); received December 31 1997 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0411.pdf 
 Identifier    ZNA-1998-53a-0411 
 Volume    53 
53Author    Tetsuo Asaji, Keizo Horiuchi, Takehiko Chiba, Takashige Shimizu, Ryuichi IkedaRequires cookie*
 Title    NMR * NQR and DTA * DSC Studies of Phase Transitions in Pyridinium Tetrachloropalladate(II) and Pyridinium Tetrachloroplatinate(II)  
 Abstract    From the measurements of DTA • DSC and the temperature dependences of 35 C1 NQR frequen-cies, phase transitions were detected at 150 K, 168 K, and 172 K for (pyH) 2 [PtCl 4 ], and at 241 K for (P yH) 2 [PdCl 4 ], In order to elucidate the motional state of the constituent ions in the crystals in connec-tion with the structural phase transitions, the 35 C1 NQR and 'H NMR spin-lattice relaxation times and the second moment of the 'H NMR line were measured as functions of temperature. For both com-pounds, the potential wells for the cationic reorientation are suggested to be highly nonequivalent at low temperatures. Above 168 K, the pyridinium ions in (pyH) 2 [PtCl 4 ] are expected to reorient between almost equivalent potential wells. As for (pyH) 2 [PdCl 4 j, it is expected that the orientational order of the cation still remains even above the second order transition at 241 K. A change of the potential curve from two-unequal to three-unequal wells is proposed as a possible mechanism of the second order tran-sition. The activation energies for the cationic motion in the respective model potential are derived for both compounds at high and low temperatures. 
  Reference    Z. Naturforsch. 53a, 419—426 (1998); received December 30 1997 
  Published    1998 
  Keywords    Phase transition, NQR, NMR, Spin-lattice relaxation, DSC 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0419.pdf 
 Identifier    ZNA-1998-53a-0419 
 Volume    53 
54Author    Lucia Calucci, Claudia Forte, Marco Geppi, CarloAlberto VeraciniRequires cookie*
 Title    Dynamics of Liquid Crystals by Means of 2 H-NMR: a Comparison between 4,4'-bis(hexyloxy)azoxybenzene and the Derivative Pd(II) Complex AZPAC  
 Abstract    In the present work we report a molecular dynamics investigation of the two mesogens 4,4'-bis(hexyloxy)azoxybenzene (HL) and its Pd(II) acetylacetonate derivative Azpac in their nematic phases. Deuterium Zeeman and quadrupolar spin-lattice relaxation times have been measured at 46.04 MHz on two isotopomers of Azpac (Azpac-d 4 and Azpac-c/ 26 > deuteriated on the aromatic core and on the alkoxy chains, respectively) and on HL-d 4 , an isotopomer of HL partially deuteri-ated on the aromatic core, by means of the Wimperis pulse sequence. The spectral densities obtained from the measured relaxation times are discussed in terms of internal and overall molecular motions. A small step rotational diffusion model for the overall molecular motions, superimposed on a free rotational model for internal motions, allowed diffusion coefficients for molecular spinning and tumbling and for phenyl ring rotations to be derived for HL; the same models were used in describing the dynamics of Azpac. 
  Reference    Z. Naturforsch. 53a, 427—435 (1998); received October 31 1997 
  Published    1998 
  Keywords    Liquid Crystals, Deuterium Relaxation, Molecular Dynamics, Metallomesogens, NMR 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0427.pdf 
 Identifier    ZNA-1998-53a-0427 
 Volume    53 
55Author    Masao Hashimoto, Yuko Monobe, Hiromitsu Terao, Haruo Niki, Koichi ManoRequires cookie*
 Title    Phase Transition and Crystal Dynamics of 4-Bromobenzyl Alcohol  
 Abstract    For the title compound a phase transition from Phase II to Phase I (low and room temperature phases, respectively) was found at ca. 217 K. The temperature dependence of the 8 'Br NQR frequency and that of the dielectric constant showed anomalies at ca. 195 K that were tentatively attributed to a higher order phase transition. A similar anomaly was found at ca. 218 K for 4-chlorobenzyl alcohol which showed a II-I transition at 236 K. The dielectric dispersion observed for both compounds at low temperatures indicates an excitation of a molecular motion with the dielectric relaxation rate of ca. 1 kHz. The temperature dependence of the sl Br NQR frequencies of 2-and 3-bromobenzyl alcohol, measured at T > 77 K, gave no evidence of phase transition in their crystals. 
  Reference    Z. Naturforsch. 53a, 436—441 (1998); received March 24 1998 
  Published    1998 
  Keywords    NQR, Phase Transition, Molecular Motion, Dielectric Dispersion 
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 Identifier    ZNA-1998-53a-0436 
 Volume    53 
56Author    Mutsuo Igarashi, Noriaki Okubo, Ryozo YoshizakiRequires cookie*
 Title    Na Nuclear Spin-Lattice Relaxation in Dehydrated Zeolite NaY  
 Abstract    The spin-lattice relaxation time T\ of 2, Na-NMR in dehydrated zeolite NaY has been measured from 26 to 300 K. The magnetization recovery curve is not single-exponential at all measured temperatures and 1 increases in proportion to the square of temperature above 200 K. The result is analyzed with a theory of the Raman process based on covalency. The value of T\ is compared with that of NaX in which the concentration of Na is about 2 times larger than in NaY. 
  Reference    Z. Naturforsch. 53a, 442—446 (1998); received December 30 1997 
  Published    1998 
  Keywords    Dehydrated Zeolite NaY, 23 Na-NMR, T\ \ Raman Process, Phonon Spectrum 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0442.pdf 
 Identifier    ZNA-1998-53a-0442 
 Volume    53 
57Author    Takahiro Iijima, Kengo Orii, Motohiro Mizuno, Masahiko SuharaRequires cookie*
 Title    H and 195 Pt NMR Studies of Molecular and Electron Spin Dynamics in Paramagnetic [Cu(H 2 0) 6 ][PtCl 6 ]  
 Abstract    The temperature dependences of 2 H and l95 Pt NMR spectra and the spin-lattice relaxation time T\ were measured for [Cu(H 2 0)6][PtCl 6 ]. From the simulation of 2 H NMR spectra, the jump rate of 180° flips of the water molecules (k), the nuclear quadrupole interaction parameters (e 2 Qq/h, 77) and the electron-nucleon dipolar interaction parameter (I^D) were obtained. By measuring 2 H T\, k was estimated in the temperature range where the spectrum is insensitive to the motion of the water molecules. Above the phase transition temperature, the pre-exponential factor ko = 8x 10 n s -1 and the activation energy E a =\5 kJmol -1 for 180° flips of the water molecules were obtained from the spectral simulation and T\. l95 Pt NMR spectra showed an axially symmetric and unsymmetric powder pattern of the chemical shift anisotropy at the high and low temperature phase, respectively. For the deuterated compound, the correlation times of the electron spin in Cu 2+ were estimated from ,9;> Pt T\ and the activation energy for jumping between the different configurations of Jahn-Teller distortion A = 200 K was obtained. 
  Reference    Z. Naturforsch. 53a, 447—152 (1998); received December 31 1997 
  Published    1998 
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 Identifier    ZNA-1998-53a-0447 
 Volume    53 
58Author    Junko Kimura, Takeshi Fukase, Motohiro Mizuno, Masahiko SuharaRequires cookie*
 Title    Studies of Successive Phase Transitions and Molecular Motions in [Mg(H 2 0) 6 ][SiF 6 ] by 12 H and 19 F NMR  
 Abstract    The successive phase transitions of [Mg(H?0)6][SiF6] were studied by measuring 2 H NMR spectra. The quadrupole coupling constant e 2 Qq/h and asymmetry parameter 77 changed drastically at each transition temperature. 12 H and 19 F NMR T\ were measured for this compound to study the relation between the molecular motions and the successive phase transitions. The activation energy E a and the pre-exponential factor TO for the reorientation of [SiFö] 2 ~ were estimated as 28 kJmol" 1 and 6.0x 10~ 14 s, and those of the 180° flip of H 2 0 as 33 kJmol -1 and 4.0x 10" 14 s. These two motions occur rapidly even in phase V. For the reorientation of [Mg(H20)6] 2+ , E a = 62 kJmol -1 and TO = 1.1 x 10 -16 s were obtained from the simulation of : H NMR spectra. The jump rate of this motion is of the order of 10 4 -10 6 s _I in phase II. These results suggest that the successive phase transitions are closely related to the motion of [Mg(H 2 0) 6 ] 2+ . 
  Reference    Z. Naturforsch. 53a, 453—158 (1998); received December 31 1997 
  Published    1998 
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 Identifier    ZNA-1998-53a-0453 
 Volume    53 
59Author    Hironobu Tada, Hirokazu Nakayama, Nobuo NakamuraRequires cookie*
 Title    Dynamic Properties and Phase Transitions in A 2 ZnBr 4 (A= (CH 3 ) 4 N and (CH 3 ) 4 P) as Studied by 79 Br NQR and Multinuclear NMR  
 Abstract    In order to understand the mechanism of ferroelastic phase transitions in A 2 ZnBr 4 (A = (CH 3) 4 N and (CH 3) 4 P), the temperature dependences of 79 Br NQR frequencies and the spin-lattice relaxation times were measured. The temperature dependences of the 'H and 31 P spin-lattice relaxation times were mea-sured as well for a possible correlation between the cation dynamics and the phase transition. Although the phase transition temperatures of these two compounds differ much (-100 K), the correlation times for the cation reorientation at the individual transition temperatures amount to some 10~" s for both compounds. 
  Reference    Z. Naturforsch. 53a, 459—465 (1998); received December 31 1997 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0459.pdf 
 Identifier    ZNA-1998-53a-0459 
 Volume    53 
60Author    Yasumasa Tomita, Koji Yamada, Hiroshi Ohki, Tsutomu OkudaRequires cookie*
 Title    Structure and Dynamics of Li 3 InBr 6 and NaInBr 4 by Means of Nuclear Magnetic Resonance  
 Abstract    Li 3 InBr 6 and NaInBr 4 have been synthesized and characterized by means of DTA, 8 'Br NQR, 6 Li, 7 Li, 23 Na, and ll5 In NMR, and AC conductivity. These measurements revealed the presence of phase transitions and cationic diffusion in both compounds. From the spin-lattice relaxation times of 1 Br NQR and the peak widths of 7 Li and 23 Na NMR spectra, it is deduced that the conduction is due to cat-ionic diffusion. The activity energy for the Li + diffusion was found to be 24 kJ/mol for Li 3 InBr 6 . 
  Reference    Z. Naturforsch. 53a, 466—472 (1998); received January 26 1998 
  Published    1998 
  Keywords    NQR, NMR, Spin-lattice Relaxation Time, AC Conductivity, Cation Diffusion 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0466.pdf 
 Identifier    ZNA-1998-53a-0466 
 Volume    53 
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