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1Author    Motohiro Mizuno, Tetsuo Asaji, Atsushi Tachikawa, The Late, Daiyu NakamuraRequires cookie*
 Title     
 Abstract    h lo r in e N Q R S p in -L a ttic e R e la x a tio n a n d E le c tro n S p in D y n a m ic s in P a r a m a g n e tic [ C o (H 20) 6] I P tC l 6| Chlorine NQR spin-lattice relaxation times T1Q were determined for [Co(H,0)6][PtCl6] at 4.2 400 K. Above ca. 350 K, T1Q decreased rapidly showing the onset of a reorientation of [PtCl6]2-. The activation energy Ea of this reorientation was determined as 125 ± 15 kJ mol ~1. With decreasing temperature, Tlfi showed a maximum at ca. 250 K. Below ca. 200 K, Tl(. is governed by the magnetic dipolar interaction between chlorines and paramagnetic Co2+ ions and is inversely proportional to the electron spin correlation time re of Co2 . Te is shown to be determined by the electron spin-lattice relaxation time Tle and the temperature independent correlation time rs for the spin-exchange between neighbouring ions above and below ca. 50 K, respectively. The temperature dependence of Tle is explained by assuming the Orbach process with an energy gap A/k of 530 + 20 K as Tle = 5 x 10~14 exp(530/T)s. ts was estimated to be 0.9 x 10"10 s. The temperature dependence of the ESR linewidth of Mn2+ impurities in single crystal was also measured, intending to study Co2+ spin dynamics. The limit of the ESR method is discussed by comparing the obtained results with those of the NQR method. 
  Reference    Z. Naturforsch. 46a, 1103 (1991); received September 17 1991 
  Published    1991 
  Keywords    Spin-lattice relaxation, NQR, ESR, Reorientation, Orbach process 
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 TEI-XML for    default:Reihe_A/46/ZNA-1991-46a-1103.pdf 
 Identifier    ZNA-1991-46a-1103 
 Volume    46 
2Author    Silvia Wigand, Tetsuo Asaji, Ryuichi Ikeda, Daiyu NakamuraRequires cookie*
 Title    Reorientational Motion of Trihalogenomethyl Groups in Organic Compounds as Studied by 35 C1 NQR and 19 F NMR Spectroscopy  
 Abstract    Trihalogenomethyl derivatives of 4-chloroacetanilide, 4-ClC6HfNHCOCCl3,4-ClC6H4NHCOCF2Cl, and 4-ClC6H4NHCOCF3 were prepared. The 35 C1 NQR and 79 F NMR spin-lattice relaxation times T1Q and T1F, respectively, of these compounds were measured at various temperatures. On heating, T1Q of the CC13 and CF2C1 groups decreased rapidly above ca. 110 and 150 K, respectively, showing the onset of reorientation of the trihalogenomethyl group about the pseudo-triad axis. The activa-tion energies were determined to be 27 and 13kJmol _1 for the CC13 and CF2C1 reorientation, respectively. The temperature dependences of the 19 F NMR T1F of the CF2C1 and CF3 groups lead to activation energies of 13 and 4.3 kJ mol~ 1 , respectively, for the same reorientations. T1F of the CF3 group observed above ca. 200 K was attributed to the spin-rotational interaction. The TIQ 1 of ring-chlorine in 4-ClC6H4NHCOCCl3 and 4-ClC6H4NHCOCF3 can be interpreted by the T" law with « = 2.2 and 1.1, respectively, whereas that of 4-ClC6H4NHCOCF2Cl by the sum of two contributions: T" law (n = 2.0) and the modulation mechanism due to the CF2C1 reorientation. 
  Reference    Z. Naturforsch. 47a, 265—273 (1992); received July 19 1991 
  Published    1992 
  Keywords    Spin-lattice relaxation, NQR, NMR, Reorientational motion 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0265.pdf 
 Identifier    ZNA-1992-47a-0265 
 Volume    47 
3Author    Tetsuo Asaji, Masaki Ohkawa, Takehiko Chiba, Makoto KagaRequires cookie*
 Title    Successive Phase Transitions in Potassium Hexachloroselenate(IV) Revealed by 35 C1 NQR  
 Abstract    K 2 SeCl 6 undergoes structural phase transitions of first order at 35 K, 65 K, and 79 K. The temperature dependence of the ? C1 NQR spin-lattice relaxation time suggests that the phase transitions at 65 K and 79 K are displacive ones associated with a resonant soft mode. The presence of a precursor cluster is suggested by the temperature dependence of the signal intensity above 79 K. 
  Reference    Z. Naturforsch. 51a, 705—709 (1996); received October 20 1995 
  Published    1996 
  Keywords    Phase transition, Soft mode, NQR, Spin-lattice relaxation 
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 TEI-XML for    default:Reihe_A/51/ZNA-1996-51a-0705.pdf 
 Identifier    ZNA-1996-51a-0705 
 Volume    51 
4Author    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 
5Author    H. Nishihara, T. Kanomata, K. Sato, N. Suzuki, T. HaradaRequires cookie*
 Title    NMR of 51 V in VRuP: Possible Onset of Charge-Density-Waves  
 Abstract    NMR experiments are reported for VRuP which has an orthorhombic TiNiSi structure and shows anomalies in the temperature dependence of the electric conductivity and static susceptibility. A field-swept spectrum of 5 'V perturbed by a quadrupole interaction has been observed, which shows no anomalous temperature dependence. However, the metallic spin-lattice relaxation rate decreases in a stepwise fashion with decreasing temperature at around 200 K, in accordance with the resistivity and the susceptibility data, suggesting a possible CDW formation in this material. 
  Reference    Z. Naturforsch. 53a, 524—527 (1998); received January 26 1998 
  Published    1998 
  Keywords    NMR, CDW, VRuP, 51 V, Spin-Lattice Relaxation 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0524.pdf 
 Identifier    ZNA-1998-53a-0524 
 Volume    53 
6Author    Makoto Kaga, Piotr Koziol, Tetsuo Asaji, Daiyu NakamuraRequires cookie*
 Title    Electric field Gradient Modulation by Motion of Lone-Pair Electrons in [(CH 3 ) 3 S] 2 MC1 6 (M = Pt, Sn) as a Possible Relaxation Mechanism of Chlorine Nuclear Quadrupole Resonance  
 Abstract    The temperature dependence of the chlorine NQR spin-lattice relaxation time T^was observed for trimethylsulfonium hexachlorometallates(IV), [(CH 3) 3 S] 2 MC1 6 (M = Pt, Sn), trimethylammonium hexachlorostannate(IV), [(CH 3) 3 NH] 2 SnCl 6 , and tetramethylphosphonium hexachlorostannate(IV), [(CH 3) 4 P] 2 SnCl 6 . The quadrupolar relaxation in [(CH 3) 3 NH] 2 SnCl 6 and [(CH 3) 4 P] 2 SnCl 6 can be described by the usual librational and reorientational motion of the complex anion at lower and higher temperatures, respectively. Besides T 1Q due to these two mechanisms, T 1Q minimum was observed at ca. 90 and 120 K for [(CH 3) 3 S] 2 PtCl 6 and [(CH 3) 3 S] 2 SnCl 6 , respectively, which is attributable to the electric field gradient modulation by the motion of the [(CH 3) 3 S] + cation having lone-pair electrons. The activation energies for the isotropic reorientation of the complex anion were determined as46,65, 59, and 60 kJ mol^ for [(CH 3) 4 P] 2 SnCl 6 , [(CH 3) 3 NH] 2 SnCl 6 , [(CH 3) 3 S] 2 PtCl 6 , and [(CH 3) 3 S] 2 SnCl 6 , respectively. 
  Reference    Z. Naturforsch. 45a, 1033—1037 (1990); received May 26 1990 
  Published    1990 
  Keywords    Nuclear Quadrupole Resonance, Spin-Lattice Relaxation, EFG Modulation, Lone-Pair Electrons 
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 TEI-XML for    default:Reihe_A/45/ZNA-1990-45a-1033.pdf 
 Identifier    ZNA-1990-45a-1033 
 Volume    45 
7Author    D. BrinkmannRequires cookie*
 Title    Probing the Electronic Structure of Y-Ba-Cu-O Superconductors by Copper NQR/NMR  
 Abstract    The paper discusses some NQR/NMR studies performed on Y-Ba-Cu-O superconductors at the University of Zürich. It is shown how the resonance methods can yield information on electronic properties of quite different character. The review deals with: (1) the temperature and pressure dependence of Cu NQR frequencies in YBa 2 Cu 4 O g (1-2-4); (2) an NQR study of the properties of Ca substituted 1-2-4; (3) the temperature dependence of the Cu Knight shifts in 1-2-4; (4) the NMR of plane Cu2 in the paramagnetic state of YBa 2 Cu 3 0 6 ; (5) the dependence on temperature, pressure and orientation of the Cu spin-lattice relaxation in 1-2-4. 
  Reference    Z. Naturforsch. 47a, 1—6 (1992); received September 20 1991 
  Published    1992 
  Keywords    NQR, NMR, High-temperature superconductors, Knight shift, Spin-lattice relaxation 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0001.pdf 
 Identifier    ZNA-1992-47a-0001 
 Volume    47 
8Author    Makoto Kaga, Tetsuo Asaji, Ryuichi Ikeda, Daiyu NakamuraRequires cookie*
 Title    Chlorine Nuclear Quadrupole Relaxation and Cationic Motion in Trimethylsulfonium Hexachloroselenate(IV): [(CH 3 ) 3 Sl 2 SeCl^  
 Abstract    The 35 C1 NQR spin-lattice and spin-spin relaxation times, 7^ and T2Q, respectively, and the 'H NMR spin-lattice relaxation time T1H at 32 and 60 MHz were determined for [(CH3j3S]2SeCl6 as functions of temperature. The rapid decrease of observed above ca. 250 K with increasing temperature was attributed to the onset of reorientation of the [SeCl6] 2 " complex anion with the activation energy £a = 42 + 5 kJ mol -1 . When cooled from ca. 250 K, T1Q showed an anomalous decrease. This 7"1Q decrease was explained by electric field gradient modulation related to some cationic motion. Possible origins of the cationic motion are discussed. 
  Reference    Z. Naturforsch. 47a, 274—276 (1992); received July 19 1991 
  Published    1992 
  Keywords    Spin-lattice relaxation, NQR, NMR, EFG modulation, Molecular motion 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0274.pdf 
 Identifier    ZNA-1992-47a-0274 
 Volume    47 
9Author    Takashige Shimizu, Tetsuo Asaji, Daiyu Nakamura, Ryuichi IkedaRequires cookie*
 Title    Uniaxial Reorientation of Octahedral Complex Anions Excited in Triethylammonium Hexachlorostannate (IV) Crystals  
 Abstract    The temperature dependence of the 35 C1 NQR spin-latticew relaxation time T1Q has been deter-mined for the three resonance lines observed in [(C2H5)3NH]2SnCl6. The higher frequency lines fade out around 150 K upon heating, whereas the lowest line shows up to room temperature no anomaly, although these three lines are assigned to chlorines belonging to the same complex anion. The T1Q values of the higher two lines decrease exponentially around the fade-out temperature, where T iq of the lowest line shows no such behavior. These results are explained by the onset of uniaxial reorientations of the octahedral complex ions by 90° about the Cl-Sn-Cl axis containing the lowest frequency chlorines. The activation energy (£J of this reorientation (22-24 kJ moP 1) is the lowest so far reportd for [SnCl6] 2-ions. £a about the other axes is 67 kJ mop 1 , indicating a remarkable anisotropic reorientation. 
  Reference    Z. Naturforsch. 47a, 283—287 (1992); received July 19 1991 
  Published    1992 
  Keywords    Spin-Lattice Relaxation, NQR, NMR, Reorientational Motion, Hydrogen Bond 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0283.pdf 
 Identifier    ZNA-1992-47a-0283 
 Volume    47 
10Author    Takeshi Kyan, Hamagawa, Takahiro Isono, Masao HashimotoRequires cookie*
 Title    Hiroshi  
 Abstract    The crystal structure of cyclohexylhemiacetal (cycHx-CH) was determined at 296 K: monoclinic, space group P2 Jc, a =1028.7 (9), b = 609.5 (1), c = 1811.9 (4) pm, and ß = 99.79 (3)°, Z -4, R = 0.0552. The three 5s Cl NQR lines in cycHx-CH, T., T2, and T2*, were measured by a pulsed method at 80-300 K. Below 200 K Tf 1 obeyed the T law well, indicating that the spin lattice relaxation is governed by lattice vibrations. The reorientation of CC13 seems to be responsible for the sharp T: drop observed above 250 K. Shoulders in the T { vs. 1/T curves indicate the presence of Ti minima at about 240 K. A fluctuation of the EFG due to a dynamic disorder of hydrogen atoms in the OH groups is assumed to explain the T x minima. 
  Reference    Z. Naturforsch. 47a, 299 (1992); received July 25 1991 
  Published    1992 
  Keywords    Chlorine NQR, Spin-lattice relaxation, Hydrogen bond, Crystal structure 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0299.pdf 
 Identifier    ZNA-1992-47a-0299 
 Volume    47 
11Author    Haruo Niki, Hirotaka Odahara, Katsuji Tamaki, Masao HashimotoRequires cookie*
 Title    Inequivalent Reorientation of the Trichloromethyl Groups in l,4-Bis(TrichloromethyI) Benzene as Studied by Pulsed 35C1NQR  
 Abstract    The temperature dependence of Ti of 35C1 N Q R o f the title com pound evidenced that the three crystallographically inequivalent CC13 groups have different potential barriers against reorientation (about 30, 36, and 42 kJ/mol). An intramolecular interaction between rc-electrons on the benzene ring and the C -C l bond is proposed to interpret the characteristic frequency splitting com m on to the 35C1 N Q R spectrum of each of the three inequivalent CC1? groups. The magnitude of T2 of each Cl atom is interpreted by intra-and intermolecular H • • • Cl interactions. It was found that only part of the temperature dependence of the N Q R frequency can be interpreted by reorientation. 
  Reference    Z. Naturforsch. 49a, 273—2 (1994); received July 23 1993 
  Published    1994 
  Keywords    Chlorine NQ R, Spin lattice relaxation, Transeverse relaxation, M olecular structure 
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 TEI-XML for    default:Reihe_A/49/ZNA-1994-49a-0273.pdf 
 Identifier    ZNA-1994-49a-0273 
 Volume    49 
12Author    Masao Hashimoto, Shuji Matsumoto, Masakazu Kunitomo, Haruo Niki, Hirotaka Odahara, Katsuji TamakiRequires cookie*
 Title    35C1 NQR Relaxation and Hydrogen Bond in Some Chloral Hemiacetals  
 Abstract    The crystal structure of chloral ethylhemiacetal has been determined at 291 K: monoclinic, space group C f -P 2 lt Z = 2, a = 854.5(1), b = 594.0(3), c = 853.3(1) pm, ß = 108.30(2)°, R = 0.0962. A sharp decrease of the spin lattice relaxation time 7i found for the 35C1 N Q R o f the CC13 groups in chloral methyl-, ethyl-and n-heptylhemiacetals is attributed to the onset of reorientation of the group over a potential barrier o f ca. 39, 37, and 32 kJ/m ol, respectively. An unusual vs. 1/T curve with a 7i minimum superimposed on the sharp decrease of 7\ due to the reorientation was observed for each of the three Cl N Q R lines of nH p-C H . This phenom enon is tentatively ascribed to a fluctuation of EFG caused by jum ping m otion o f the hydrogen atom s in the OH groups. 
  Reference    Z. Naturforsch. 49a, 279 (1994); received August 16 1993 
  Published    1994 
  Keywords    Crystal structure, Hydrogen bond, Chlorine N Q R, Spin lattice relaxation 
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 Identifier    ZNA-1994-49a-0279 
 Volume    49 
13Author    Masao Hashimoto, Takahiro Isono, Noriko Yomesaka, Haruo Niki, Hiroshi Kyan, Takeshi HamagawaRequires cookie*
 Title    Reorientation of the CC1 3 Group in Chloral 4-Chlorobenzyl- hemiacetal. A Pulsed 35 C1 NQR and X-ray Study  
 Abstract    The crystal structure of the title compound was determined at 291 K: monoclinic, space group C^h-P21/n, Z = 4, a = 1693.2(1), 6 = 579.3(1), c = 1232.5(1) pm, and ß = 107.21 (1)°, R = 0.0415. A sharp decrease of of Cl NQR found at T> 270 K for the CC13 group is attributed to the reorientation of the group over a potential barrier of ca. 50 kJ/mol. Intermolecular interactions between the CC13 and the neighboring atoms seem to dominate the magnitude of the potential barrier. T{~ 1 of the 35 C1 NQR of the Cl atom on the benzene ring obeyed the T 2 law well in the range 80 < T/K <270, while at T>280 K it deviated from the T 2 law. 
  Reference    Z. Naturforsch. 47a, 293—298 (1992); received July 25 1991 
  Published    1992 
  Keywords    Crystal structure, Hydrogen bond, Chlorine NQR, Spin lattice relaxation, Atom-atom potential method 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0293.pdf 
 Identifier    ZNA-1992-47a-0293 
 Volume    47 
14Author    Noriaki Okubo, Harutaka Sekiya, Chiaki Ishikawa, Yoshihito AbeRequires cookie*
 Title    Br Nuclear Quadrupole Relaxation in the High Temperature Modification of Niobium Pentabromide  
 Abstract    The spin-lattice relaxation time of 79 Br NQR has been measured between 4.2 K and room temperature. The result is compared with that of 35 C1 NQR in NbCl 5 . The origin of the relaxation is attributed to the quadrupolar interaction and the temperature dependence is explained by the Raman process. The Debye temperature is determined to be 94 K and the relaxation time is related with the NQR frequency through the covalency. 
  Reference    Z. Naturforsch. 47a, 713—720 (1992); received December 13 1991 
  Published    1992 
  Keywords    Niobium pentabromide, Nuclear quadrupole resonance, Spin-lattice relaxation, Raman process, Debye temperature 
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 TEI-XML for    default:Reihe_A/47/ZNA-1992-47a-0713.pdf 
 Identifier    ZNA-1992-47a-0713 
 Volume    47 
15Author    Stefan Jurga, Kazimierz Jurga, EduardC. Reynhardt, Piotr KatowskiRequires cookie*
 Title    A Proton NMR Study of n-Decylammonium Chain Dynamics in the Perovskite-type Layered Compound (C 10 H 21 NH3) 2 CdCl4  
 Abstract    A detailed proton second moment and spin-lattice relaxation time investigation of the bilayered compound (C 10 H 21 NH 3) 2 CdCl 4 is reported. In the low temperature phase the methyl group exe-cutes a classical threefold reorientation, while the NH 3 group is involved in a similar reorientation in an asymmetric potential well. Evidence for defect chain motions in this phase has been found, and infomation regarding the potential wells associated with these motions has been extracted from the data. In the high temperature phase, slow chain defect motions and fast fourfold reorientations of chains about their long axes, parallel to the normal to the bilayer, have been observed. 
  Reference    Z. Naturforsch. 48a, 563—569 (1993); received October 9 1992 
  Published    1993 
  Keywords    Bilayered compounds, Phase transition, Spin-lattice relaxation, Molecular motions, Defect motions 
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 TEI-XML for    default:Reihe_A/48/ZNA-1993-48a-0563.pdf 
 Identifier    ZNA-1993-48a-0563 
 Volume    48 
16Author    Tetsuo Asaji, Hideshi Tomizawa, Ryuichi IkedaRequires cookie*
 Title    Structural Phase Transition of N,N-Dimethylnitramine as Studied by 14N Nuclear Quadrupole Resonance  
 Abstract    The 14N nuclear quadrupole relaxation time and resonance frequencies v+, v_, and vd of N,N-dimethylnitramine were measured between 14 and 313 K. The frequency increase of v+ and v_ observed below Tc (108 K) is explained by the increase o f prc electrons in the am ino nitrogen caused by the deformation of the m olecular skelton, which is planar above Tc. The sharp Tip minima for v+ and v_ observed at Tc are attributed to the softening o f vibration modes on both sides of Tc. The fluctuation o f the nitrogen-hydrogen m agnetic dipolar interaction due to C H 3 reorientation was detected as a broad T'lQ minimum observed around 84 K. A logarithmic divergence of Tu31 observed on the high-temperature side o f Tc suggests the presence o f a diffusive or overdamped-type soft mode. 
  Reference    Z. Naturforsch. 49a, 253 (1994); received August 10 1993 
  Published    1994 
  Keywords    M olecular crystal, Phase transition, Soft mode, NQ R, Spin-lattice relaxation 
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 TEI-XML for    default:Reihe_A/49/ZNA-1994-49a-0253.pdf 
 Identifier    ZNA-1994-49a-0253 
 Volume    49 
17Author    Hisashi Honda, Shin'. Ichi Ishimaru, Noriko Onoda-Yamamuro, Ryuichi IkedaRequires cookie*
 Title     
 Abstract    y n a m ic s o f N i t r i te I o n s in th e I o n ic P la s tic C r y s ta l T IN O 2 s tu d ie d b y 15N a n d 205T1 N The temperature dependences of the NMR spin-lattice and spin-spin relaxation times and the NMR spectra of 15N in T115N02 were observed in the plastic phase (282.4 K < T < 459 K) and the low-temperature phase. From the analysis of 15N NMR data, we attributed the motion reported in dielectric and TI NMR studies in the low-temperature phase to the 180°-flip of NO^~ ions which takes place with an activation energy of 14 kJ mol-1. In the plastic phase, we detected isotropic NOJ reorientation with an activation energy of 13.5 kJ mol-1 and a new anionic motion with 10 kJ mol-1. 
  Reference    Z. Naturforsch. 50a, 871—875 (1995); received June 16 1995 
  Published    1995 
  Keywords    Solid NMR, Spin-lattice relaxation, Plastic crystal, Phase transition, Chemical shift anisotropy 
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 TEI-XML for    default:Reihe_A/50/ZNA-1995-50a-0871.pdf 
 Identifier    ZNA-1995-50a-0871 
 Volume    50 
18Author    Mutsuo Igarashi, Noriaki Okubo, Shuichi Hashimoto, Ryozo Yoshizaki, DeokJoon ChaRequires cookie*
 Title    Na Spin-Lattice Relaxation Measurements in Dehydrated Na-X Zeolite  
 Abstract    The spin-lattice relaxation time T\ of 23 Na-NMR in a dehydrated Na-X zeolite has been measured from 20 to 300 K. The recovery curve is not single-exponential at all measured temperatures and T\~ 1 increases with the square of temperature around room temperature. The results are analyzed by assuming non-equivalent sites and by applying the theory of the Raman process based on covalency. 
  Reference    Z. Naturforsch. 51a, 657—661 (1996); received October 17 1995 
  Published    1996 
  Keywords    Dehydrated Na-X zeolite, 23 Na-NMR, spin-lattice relaxation, Raman process, nonequivalent sites 
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 TEI-XML for    default:Reihe_A/51/ZNA-1996-51a-0657.pdf 
 Identifier    ZNA-1996-51a-0657 
 Volume    51 
19Author    Yoshio Kume, Tetsuo AsajiRequires cookie*
 Title    Chlorine-35 NQR Study of a Structural Phase Transition in (ND 4 ) 2 PdCV  
 Abstract    Temperature dependences of 35 C1 NQR frequencies and spin-lattice relaxation times were measured at 4.2 to 400 K for natural and deuterated ammonium hexachloropalladate. It was confirmed that only the deuterated salt undergoes a first order phase transition at 30 K. The crystal structure of the low-tem-perature phase is predicted to be the same as that of the deuterated ammonium hexachloroplatinate and hexachloroplumbate. The mechanism of the deuteration-induced phase transition is discussed. 
  Reference    Z. Naturforsch. 53a, 514—517 (1998); received March 24 1998 
  Published    1998 
  Keywords    Isotope Effect, Phase Transition, Chlorine NQR, Spin-lattice Relaxation, Deuterated Ammonium Hexachloropalladate 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0514.pdf 
 Identifier    ZNA-1998-53a-0514 
 Volume    53 
20Author    Hiroshi Miyoshi, Keizo Horiuchi, Narumi Sakagami, Kenichi Okamoto, Ryuichi IkedaRequires cookie*
 Title    C1 NQR, *H NMR, and X-Ray Diffraction Studies in a Hydrogen Bonded Complex Na 2 PtCl 6 * 6H z O  
 Abstract    The 35 C1 NQR frequencies, spin-lattice relaxation time and X H NMR relaxation time were measured on crystalline Na 2 PtCl 6 • 6H z O at 77-350 K. The presence of three nonequivalent chlo-rine sites found by X-ray diffraction measurement is in agreement with the observed three NQR lines, which have different temperature dependences attributable to differences in the direction of H-bonding with water molecules. The three NQR lines correspond to three kinds of chlorines with different Pt-Cl distances and H-bond directions. 
  Reference    Z. Naturforsch. 53a, 603—607 (1998); received October 31 1997 
  Published    1998 
  Keywords    CI NQR, X-Ray Diffraction, Spin-Lattice Relaxation, Quadrupole Coupling Constant, Hydrogen Bond 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0603.pdf 
 Identifier    ZNA-1998-53a-0603 
 Volume    53 
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