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We have conducted 63,65Cu nuclear quadrupole resonance (NQR) measurements on A-site ordered perovskite compounds LaCu 3 Ru 4 O 12 and NdCu 3 Ru 4 O 12 to investigate their ground state and spin fluctuations. While there is only one Cu site in the crystal structure, multiple NQR resonance lines were observed. This is presumed to be due to the presence of slight distortion and lattice defects in the samples. The nuclear spin-lattice relaxation rate divided by temperature, 1 / T 1 T , for LaCu 3 Ru 4 O 12 showed almost constant value indicating the Fermi-liquid state. A remarkable increase in 1 / T 1 T due to spin fluctuations was observed in NdCu 3 Ru 4 O 12 . Furthermore, an evident magnetic phase transition at T M = 0.6 K was revealed from the distinct peak of 1 / T 1 T and the broadening of the NQR spectrum.

We report $^{31}$P NMR measurements under various magnetic fields up to 7 T for the intermediate valence compound EuNi$_2$P$_2$, which shows heavy electronic states at low temperatures. In the high-temperature region above 40 K, the Knight shift followed the Curie--Weiss law reflecting localized $4f$ states. In addition, the behavior corresponding to the temperature variation of the average valence of Eu was observed in the nuclear spin-lattice relaxation rate $1/T_1$. With the occurrence of the Kondo effect, $1/T_1$ was clearly reduced below 40 K, and the Knight shift becomes almost constant at low temperatures. From these results, the formation of heavy quasiparticles by the hybridization of Eu $4f$ electrons and conduction electrons was clarified from microscopic viewpoints. Furthermore, a characteristic spin fluctuation was observed at low temperatures, which would be associated with valence fluctuations caused by the intermediate valence state of EuNi$_2$P$_2$., Comment: 7 pages, 5 figures

A charge density wave (CDW) transition at TCDW = 243 K and a structural phase (SP) transition at approximately 100 K occur in SrAl4 with the BaAl4-type body center tetragonal structure, which is the divalent and non-4f electron reference compound of EuAl4. To understand the behaviors of the CDW and SP transitions, the 27Al NMR measurements using a single crystal and a powder sample of SrAl4 have been carried out. The line width below TCDW is modulated by an electrical quadruple interaction between 27Al nucleus and CDW charge modulation. The incommensurate CDW state below TCDW changes into a different structure below TSP. The temperature dependences of Knight shifts of 27Al(I) and 27Al(II) show the different behaviors. The temperature variation of 27Al(I) Knight shift shows anomalies at the CDW and SP transition temperatures, revealing the shift to negative side below TCDW, which is attributable to the core polarization of the d-electrons. However, 27Al(II) Knight shift keeps almost constant except for the small shift due to the SP transition. The 1/T1T of 27Al(I) indicates the obvious changes due to the CDW and SP transitions, while that of 27Al(II) takes a constant value. The density of state at the Fermi level at Al(I) site below 60 K would be about 0.9 times less than that above TCDW.

In order to microscopically investigate the properties in SrGa4, the Ga NMR measurements of a powder sample were carried out. The Ga NMR spectra corresponding to Ga(I) and Ga(II) sites are obtained. The NMR spectra of 69&71Ga (a nuclear spin I = 3/2) in the powder sample of SrGa4 do not take a typical powder pattern caused by the NQR interaction, but take the spectra consisting of three well resolved resonance-lines, which indicates that the nonuniform distribution of crystal orientation in the powder sample occurs because of the magnetic anisotropy. From the analysis of the Ga NMR spectrum, it is found that the ab-plane of the crystal is parallel to the external magnetic field, which would be attributed to the anisotropy of the magnetic susceptibility with the easy axis parallel to the ab-plane. This result is also confirmed by the 69Ga NQR in SrGa4. The Knight shifts of the 69Ga(I) and 69Ga(II) shift slightly to the negative side with decreasing temperature due to the core polarization of the d-electrons. The values of the Knight shift of the 69Ga(I) and 69Ga(II) are 0.01 and –0.11 % at 4.2 K, and 0.09 and –0.08 % at 300 K, respectively. The values of the 1/ T 1 T of the NMR of both 69Ga(I) and 69Ga(II) are almost constant between 4.2 and 100 K, whose values are 1.5 s −1 K −1 at 69Ga(I) and 0.12 s −1 K −1 at 69Ga(II), while the 1/ T 1 T slightly increase above 100K with increasing temperature. The value of T 1 of 69Ga(I) is one order of magnitude less than that of 69Ga(II).

In order to microscopically investigate the magnetic properties of both paramagnetic and antiferromagnetic phases in Mn3Si (T N = 23 K), the 55Mn NMR has been carried out at temperatures between 2.2 K and 300 K. The temperature dependences of the spectrum, Knight shift (or resonance frequency shift) and spin-lattice relaxation time T 1 of 55Mn NMR have been measured. In the paramagnetic phase, only one resonance spectrum can be obtained. The observed spectrum is identified to be a signal corresponding to the Mn(II) site. In the antiferromagnetic phase, two different spectra corresponding to the Mn(I) and Mn(II) sites are found at the resonance frequencies of 145 and 6 MHz, respectively, by the zero field NMR at 4.2 K. From these results, the internal magnetic fields on the 55Mn(I) and 55Mn(II) nuclei are found to be 13.6 and 0.6 T, respectively. According to the NMR results, the helical structure in incommensurate Mn spin states is better explained compared with the transverse sinusoidal structure.

The measurement of 81Br NQR in CH3NH3HgBr3 has been carried out in the temperature range between 80 and 300 K using a pulse NQR method. The temperature dependence of 81Br NQR frequencies in CH3NH3HgBr3 has revealed that it undergoes three characteristic successive phase transitions at T = 123, 184 and 239 K. The phase transition temperature at T = 239 K is the second-order type, whereas those at T = 184 and 123 K are the first-order nature of the phase transitions. Each phase transition seems to be closely related to the motions of methyl ammonium cation as a partial or whole. The enhancement of 1/T 1 at T = 239 K indicates the onset of the molecular motion of the cation as a whole with increasing temperatures.

81Br NQR measurements of the mixed-valence compound (NH4)4SbIII SbvBrl2, which has SbvBr 6 − and SbIIIBr 6 3− octahedra in different oxidation states in the tetragonal pseudo-K2PtCl6 structure, were carried out by pulse method in the temperature range between 80 and 300 K. The phase transition temperature of T c=212Kwas redetermined. The T 1 values are quite different between SbvBr 6 − and SbIIIBr 6 3− octahedra. For all resonance lines T 1 minima were observed at T c. The T 1 behavior at T c was explained by a softening of the rotary lattice mode around a principal axis of each octahedron along the c axis of the crystal. The distinctive feature in the temperature dependence of both 81Br NQR frequencies and T 1 values for each anion indicates that the static rotation may occur for SbvBr6 but not for SbIIIBr 6 3− at T c in the low temperature phase.

For the ferrimagnetic compound ErCo 3 ( T C =401 K), a temperature-induced magnetic transition in the Co-sublattices near 100 K was reported previously. The Co-moments of two of the three non-equivalent Co-sites increase discontinuously upon cooling below this transition temperature. Here, we report on the investigation of this metamagnetic transition when the molecular field is reduced, partly substituting Er by Y. Neutron-diffraction experiments on Er 1− x Y x Co 3 compounds reveal that this temperature-induced magnetic transition vanishes for x ⩾0.3. As new phenomenon, a spin-reorientation out of the c -axis is observed near 40 K when Er is partly replaced by Y. Both phenomena are studied by neutron and NMR experiments.

The temperature dependences of T_1 and T_2 of ^Br and ^Sb NQR have been measured in order to study the phase transition at T_c = 224 K as well as the crystal dynamics in 4-aminopyridinium tetrabromoantimonate(III) (4-NH_2PyHSbBr_4). The temperature dependence of T_1 of ^Br and ^Sb NQR follows the usual T^2 law in the range from 80 to 120 K. T_1 is dominated by fluctuations of the EFG at the Br and Sb nuclei due to lattice vibrations. The T_1 vs. 1/T curves in the region between about 120 and 140 K can be described by exponential curves. The activation energies of motions obtained from these curves are similar to those from proton NMR. The exponential changes of T_1 of Br and Sb NQR are attributable to fluctuations caused by the thermal motion of 4-NH_2PyH cations. Echo signals of Br and Sb NQR in the low temperature phase could not be detected at temperatures higher than 145 and 150 K, respectively, because the S/N ratios became poor owing to the very short T_2. The echo signals could also not be detected at temperatures above T_c because of the short T_2., 論文

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, β = 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 (Tc). The 1H NMR spectra showed a sharp motional narrowing at ca. T=Tc , 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 81Br 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 81Br 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, 1H NMR line width, and 1H NMR T1.

Sb nuclear quadrupole resonance (NQR) experiment has been performed on filled skutterudite compounds CeOs 4 Sb 12 and CeRu 4 Sb 12 in order to investigate an electronic state from a microscopic point of view. Five NQR transitions originate from 121 Sb and 123 Sb were observed and the nuclear quadrupole frequency and asymmetry parameter were estimated. 1/ T 1 T 's shows exponential-like decrease with decreasing temperature above 100 K, indicating a presence of c – f hybridization gap for both compounds. 1/ T 1 T 's start to increase and show characteristic temperature dependence 1/ T 1 T ∝ T - n ( n =1/2 and 1) for CeOs 4 Sb 12 and CeRu 4 Sb 12 below ∼30 K, indicating a development of the spin fluctuation. The non-Fermi-liquid behavior in CeRu 4 Sb 12 is suggested to be caused by a magnetic instability.

121 Sb nuclear magnetic resonance (NMR) of filled skutterudite compound CeOs 4 Sb 12 has been carried out to investigate a spin fluctuation below T ∼ 25 K . In spite of a powdered sample, many sharp peaks, similar to a data for single crystal, were observed because of an orientation of the sample from the anisotropy of the magnetization. A numerical calculation well reproduces resonance fields for Sb(1) sites with H ∥ V zz . The nuclear spin-lattice relaxation rate divided by temperature 1 / T 1 T shows continuous decrease with increasing magnetic field, indicating a suppression of the spin fluctuation by the field.

Field dependence of 59 Co NMR in ferrimagnetic Er 1 - x Y x Co 3 was measured up to 8 T at 4.2 K using aligned powdered samples. For pure ErCo 3 in fields perpendicular to the c axis the resonance frequencies change discontinuously between 2 and 3 T due to a field induced metamagnetic transition. The easy axis is found to be along the c axis for x = 0 and 0.1. An average angle for the Co moments of 45 ± 5 ∘ from the c axis is obtained from field dependence of 59 Co NMR at x = 0.3 . Directions of Co moments are also found to be inclined from the c axis for x = 0.5 .

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 81Br 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 81Br NQR frequencies of 2-and 3-bromobenzyl alcohol, measured at T > 77 K, gave no evidence of phase transition in their crystals.

The oxygen content dependence of 63Cu NQR at the Cu(1) site and proton NMR have been measured in the antiferromagnetic phase of powdered samples of hydrogen-doped YBa2Cu3O6+xHy (0.07 1H NMR is a single line and the line width increases below 15 K due to magnetic interactions. The enhancements of T1 -1 and T2 -1 of 63Cu(l)NQR occur around 35 and 15 K, respectively. These enhancements increase with increasing oxygen concentration. The maximum values of T1 -1 and T2 -1 for the sample with x = 0.17 reach 200 sec-1 and more than 7 msec-1, respectively. The predominant source for the relaxation mechanism of 63Cu(l) NQR and the line broadening of 1H NMR are found to be the fluctuating magnetic field due to the staggered Cu2+ moments.

Magnetic field dependence of Co 59 NMR resonance frequencies in ferrimagnetic ErCo3 was measured in fields parallel and perpendicular to the c-axis of the crystal up to 8 T at 4.2 K. The zero field powder spectrum at 4.2 K shows three resolved lines at 23, 65, and 96 MHz, which correspond to 3b, 6c, 18h sites of Co, respectively. When field is applied along the c-axis, the resonance frequencies of 96 MHz line increase at about 10.01 MHz/T with increasing field, while those of 23 and 75 MHz lines decrease at the same rate. This means that the hyperfine field H hf is negative only for the Co 18h site, whereas at 3b- and 6c-Co it is positive. The positive H hf is resulted from a large contribution of unquenched 3d orbital moments. When field is applied perpendicular to the c-axis, the frequencies of all three resonance lines increase with increasing field, which means that H hf is negative at all the three Co sites. The resonance frequencies abruptly change around the field between 2 and 3 T due to the field induced metamagnetic transitions caused by the rotations of Er and Co magnetic moments towards the direction of the applied field from the c-axis.

Cu(1) NQR, Cu(2) zero field NMR, and proton NMR have been measured in the antiferromagnetic (AF) phase of a powdered sample of hydrogen-doped YBa 2 Cu 3 O 6.1 H 0.14 from 4.2 to 300 K. The line width of 1 H NMR increases abruptly below 20 K. The enhancements of T 2 -1 and T 1 -1 of 63 Cu(1) NQR occur around 20 and 40 K, respectively. The relaxation mechanism of T 1 of NQR changes at T rm =80 K and the time dependence of its nuclear magnetization recovery shows a nonexponential type for T T rm . The predominant source for T 1 below T rm is found to be the fluctuating magnetic fields due to the staggered Cu 2+ moments induced by the hole doping effect. Above T rm , T 1 -1 of NQR increases gradually with temperature but it is almost temperature independent above 150 K, what can not be explained by the effect of the ordered AF Cu 2+ moments in the Cu(2)O 2 plane and also by the Raman process of the lattice vibrations.

The saturation magnetization of polycrystalline CeAg 1− x In x measured in magnetic fields up to 15 T at 1.5 K is about 1.5 μ B and 1.0 μ B for x ⩽0.2 and x ⩾0.3, respectively. Reversal of the crystalline electric field (CEF) occurs from Γ 8 ground state to Γ 7 . The susceptibility can be approximated by the cubic CEF in the tetragonal phase, however, it cannot be represented in the cubic phase for x >0. The atomic shifts in the tetragonal phase widen the volume available for Ce, corresponding to reduction of about 13 kbar pressure. The results are discussed with the 5d—e g conduction band population.

The spin-lattice and spin-spin relaxation times T1 and T2 of 35Cl NQR were measured for the high (I) and low (II) temperature phases of 4-chlorobenzyl alcohol in the range 50 < T/K < 338 (transition and melting points: 236 and 343.5 K, respectively). In phase II the T1 behavior in the range 50 < T/K < 90 can be explained by lattice vibrations and that in the range 90 < T/K< 190by reorientation with an activation energy of ca. 3.8 kJ/mol. In phase I, the T1 behavior at T > 260 K is explainable by another reorientation with Ea ≈ 4.7 kJ/mol. The T1, vs. T curves revealed that in both phases the crystal dynamics is anomalous in the vicinity of the transition temperature. Lattice defects accumulated in phases I and II by the phase transition were found to be responsible for the extremely short inverse line width parameters (T2*).

We performed an 75As nuclear quadrupole resonance (NQR) measurement on CeOs4As12. The 75As-NQR spectrum shape demonstrates that the Ce-site filling fraction of our high-pressure synthesized sample is close to unity. A presence of the c — f hybridization gap is confirmed from the temperature dependence of the nuclear spin-lattice relaxation rate 1/T1. An increase of 1/T1 below ~3 K indicates a development of the spin fluctuations. The 1/T1 for CeOs4As12 shows similar behavior as that for CeOs4Sb12 with different magnitude of the c — f hybridization gap. An absence of phase transition in CeOs4As12 may be caused by the increase of the c — f hybridization, which increases the gap magnitude and reduces the residual density of state inside the gap.

The crystal structure of chloral ethylhemiacetal has been determined at 291 K: monoclinic, space group C2 2 - P21, Z = 2, a = 854.5(1), b = 594.0(3), c = 853.3(1) pm, β = 108.30(2)°, R = 0.0962. A sharp decrease of the spin lattice relaxation time T1 found for the 35Cl NQR of the CCl3 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/mol, respectively. An unusual T1 vs. 1/T curve with a T1 minimum superimposed on the sharp decrease of T1 due to the reorientation was observed for each of the three 35Cl NQR lines of nHp-CH . This phenomenon is tentatively ascribed to a fluctuation of EFG caused by jumping motion of the hydrogen atom s in the OH groups.

of the C u(l) site have been measured on the antiferromagnetic phase of a powdered sample of hydrogen-doped tetragonal YBa2Cu3O6.1H0.14 between 5 and 300 K. The line width, Δω, of 1H NMR increases abruptly below 20 K. The enhancement of T2 -1 and that of T1 -1 of 63Cu (1) NQR occurs around 20 K and 40 K, respectively. The nuclear magnetization does not recover in a simple exponential manner below 80 K. The predominant mechanism governing T1 below 80 K was found to be the fluctuating magnetic field which originates from the staggered Cu2+ moments in either the Cu(l) oxygen-deficient layer or the Cu(2)O2 plane induced by the hole doping effect. These enhancements and the abrupt increase in Δω are attributed to this fluctuating magnetic field.

The temperature dependence of T1 of 35Cl NQR of the title com pound evidenced that the three crystallographically inequivalent CCl3 groups have different potential barriers against reorientation (about 30, 36, and 42 kJ/mol). An intramolecular interaction between π-electrons on the benzene ring and the C -Cl bond is proposed to interpret the characteristic frequency splitting common to the 35Cl NQR spectrum of each of the three inequivalent CCl3 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 NQR frequency can be interpreted by reorientation.

Thermopower S and resistivity ρ of cubic Laves phase compound ErCo2 were measured from 2 to 300 K in magnetic fields up to H=15 T. ErCo2 shows a first-order magnetic transition from paramagnetic to ferrimagnetic state at Curie temperature Tc≈32 K, where the sharp jump in S(T) curve was observed with increasing temperature. Tc increases with increasing H. The magnitude of the jump of S(T) at the first-order magnetic transition increases with increasing H in magnetic field up to 3 T. At higher fields, S(T) curve shows a double transition due to separation Er and Co ordering.

The temperature and the magnetic field dependencies of magnetoresistivity of paramagnetic RCo 2 compounds (R=Y, Lu, and Sc), and paramagnetic and weakly ferromagnetic Y(Al x Co 1− x ) 2 alloys (0⩽ x ⩽0.15) have been measured at temperatures of 2–300 K, in magnetic fields up to 15 T. The magnetoresistivity is positive in paramagnetic and in weakly ferromagnetic compounds at low temperatures. A simple phenomenological model is proposed to explain the results.

Thermopower (S), resistivity (ρ), and AC susceptibility of Y 1 xGdxCo2 alloys (0 ≤ x ≤ 1) have been measured at temperatures of 2K-300 K in magnetic field from 0 to 15 T. There are 4 composition regions on the phase diagram of Y 1 x Gd x Co 2 : Kondo-type behavior is observed at 0 < x ≤0.05, magnetic cluster glass state is found for x from about 0.07 to 0.12. At higher Gd content, x≥0.13 the ground state of the 4f localized moment subsystem is ferromagnetic. The magnetoresistivity (Δρ) shows unusual large positive values in the magnetically ordered phase 0.15 < x ≤0.3.

The crystal structure of cyclohexylhemiacetal (cycHx-CH) was determined at 296 K : monoclinic, space group P21/c, 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 35Cl NQR lines in cycHx-CH, T1, T2, and T2*, were measured by a pulsed method at 80-300 K. Below 200 K T1 -1 obeyed the T law well, indicating that the spin lattice relaxation is governed by lattice vibrations. The reorientation of CCl3 seems to be responsible for the sharp T: drop observed above 250 K. Shoulders in the T1 vs. 1/T curves indicate the presence of T1 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 T1 minima.

The crystal structure of the title compound was determined at 291 K : monoclinic, space group C5 2h-P21/n, Z = 4, a = 1693.2(1), b = 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 CCl3 group is attributed to the reorientation of the group over a potential barrier of ca. 50 kJ/mol. Intermolecular interactions between the CCl3 and the neighboring atoms seem to dominate the magnitude of the potential barrier. T1 -1 of the 35Cl NQR of the Cl atom on the benzene ring obeyed the T2 law well in the range 80 ≲ T/K ≲ 270, while at T ≳ 280 K it deviated from the T2 law.

The right upper extremity of a 38-year-old man was entrapped in an underwater intake of a water duct of a dam reservoir, and he died despite being promptly rescued. His right upper extremity was swollen and exhibited purplish-red discolourations. The skin had numerous blisters and increased tension. Severe subcutaneous and muscle bleeding were observed in the right upper extremity. The circumference and volume of the right upper extremity were approximately 1.2 and 1.4 times, respectively, that the circumference and volume of the left upper extremity. The increase in weight of the right extremity was calculated to be approximately 2.1 kg; this finding indicates a severe decrease in the victim’s central blood volume. Furthermore, it is possible that much more than 2.1 kg of blood accumulated in the upper extremity upon exposure to vacuum pressure. We conclude that the victim died of circulatory collapse that was attributable to haemorrhage and re-distribution of blood as a result of vacuum pressure on the right upper extremity. Thus, we have examined the cause of death and the effects of vacuum pressure on the human body.

An 18-year-old male driving an off-road motorcycle died from complete decapitation when his motorcycle tore a roadblock chain from its attachment. The decapitation injuries of the head and the torso corresponded perfectly, without apparent loss of tissue. The severance plane passed horizontally through the upper cervical region and C4, which sustained a comminuted fracture. The sharply delineated severance edge had a band-like abrasion. The decapitation resulted from the rotational movement of the unstrung chain, which struck and strangled the driver’s neck. We were able to explain the movement of the chain and the decapitation mechanism. This case emphasizes the importance of discussing dynamics with experts to clarify a causal mechanism.

Nuclear spin-lattice relaxation time T1 of 1H in the hydrogen-doped superconductor YBa2Cu3O6.94H0.2 with Tc the spin-lattice relaxation rate T−1 between 77 and 300 K. Just below Tc the spin-lattice relaxation rate T−1 shows a fairly large enhancement at 0.93 Tc, followed by a sharp decrease with decreasing temperature. The hydrogen atoms are trapped in the single atomic site below 150 K and moving in the crystal above 170 K. From the analysis of T1, it is concluded that paramagnetic impurities exist.

The temperature dependence of the S/N ratios of three 35Cl NQR lines (v1, v2 , v3) in chloral iso-butylhemiacetal shows interesting features in the range 77-300 K. 35Cl T1 indicates that above 220 K reorientation of CCl 3 is excited, and this results in a gradual decrease in S/N. The activation energy calculated from 35Cl NQR T1 results is 30 kJ mol-1 for v1 and v2 but 25 kJ mol -1 for v 3 . The difference seems to be attributable to the motion of H in the OH group. A minimum of 35Cl NQR T2 is found around 180 K but 35Cl T1 shows no anomaly. 35Cl T2 determines the S/N ratios in the range between 130-220 K. The line broadening below 130 K is attributable to an inhomogeneity of the electric field gradient at resonant nuclei produced by lattice defects.

Continuous wave and pulsed NQR, dielectric absorption and infrared (IR) measurements were carried out to investigate the origin of the peculiar temperature dependence of the S/N ratio of the 35Cl NQR in the title compound. The dielectric and IR experiments evidenced a thermally activated jumping motion of the H atom participating in O-H O H-bonds. As T1 and T2 below 120 K were much longer than T*2 of about 10 μs, the line broadening in this temperature region was attributed to static lattice defects. A random freezing of the jumping motion may be the origin of the defects. In the range 120-170 K, S/N was extremely low and T2 was less than 10 μs, probably having a minimum in between. The short T2 is considered to be responsible for the low S/N. A minimum of S/N at about 240 K is attributed to a T1 minimum (less than 10 (μs) at that temperature.

Dielectric measurements on single crystals and DSC of the title compound (monoclinic, space group P21) revealed a ferroelectric transition at ca. 355 K (ΔH ≈ 0.5 kJ mol-1) Powder x-ray diffraction indicated that the high temperature phase is also monoclinic and the change in volume at the transition is very small. A displacement of hydrogen atoms is considered as responsible for the appearance of ferroelectricity. The 35Cl NQR signals at ca. 77 K were considerably broad, but a drastic narrowing took place after the compound had once experienced the phase transition. A tentative assignment of the NQR spectrum was made from a calculation of the NQR frequencies based on the CNDO/2 method. Another phase transition was evidenced by a small drift of the DSC curve and a slight anomaly of the dielectric behavior around 358 K. The present 1H NMR experiments gave no indication of the onset of torsional motion of the NH2 group reported to occur at ca. 210 K.

The electrical resistivity ρ and the thermopower S of the single crystalline sample of the Heusler compound Mn3Si have been measured in the temperature range between 2 and 300 K under high pressures up to 2.2 GPa. The temperature variations of ρ and S indicate the characteristic features at the Neel temperature TN. An additional anomaly in S(T), related to the 3Q satellites in SDW, is observed at P > 1 GPa, and it disappears at P > 1 GPa. The Neel temperature, obtained from ρ(T) and S(T) curves, increases with increasing pressure. The pressure dependences of the residual resistivity and the thermopower at T = 2 K show the discontinuous changes at P ≈ 1 GPa, indicating a pressure induced phase transition.

To investigate the magnetic properties of the Hf-rich side (0.5 ≤ x ≤ 1.0) of Cu(Cr1-x:Hfx)2S4 from a microscopic point of view, 63Cu NMR has been performed at temperatures between 4.2 and 300 K. Temperature dependencies of the Knight shift and spin- lattice relaxation time (T1) have been measured. As for 0.7 ≤ x ≤ 1.0, the Knight shift gradually shifts to a negative side with decreasing temperature due to the core polarization of d conduction electrons. The temperature dependence of 1/T1T in this range of x indicates that the T1T is constant in all temperature region. On the other hand, in the range of 0.5 ≤ x ≤ 0.7, the Knight shift rapidly shifts to negative side below about 130 K because of the core polarization of d conduction electrons. In this range of x, the values of 1/T1T at high and low temperatures take constant values. The value at low temperatures is approximately twice compared with those at high temperatures. The density of state at the Fermi level in the low temperature region would be about 1.3 times larger than that in the high temperature region.

In order to investigate the heavy-fermion like behavior of amorphous alloy Ce x Mn 100 - x , the NMR measurements of 55Mn ( I = 5 2 ) in Ce65Mn35 have been carried out from 4.2 to 270 K using powdered sample. A broadened NMR spectrum containing five NQR lines split due to NQR interaction is observed. Quadrupole coupling constant 3 e 2 Qq / 2 I ( 2 I - 1 ) h is gradually changed from about 1.8 MHz at 4.2 K to about 1.6 MHz at 270 K. Temperature dependence of the line width is expressed in the Curie–Weiss law with θ p = - 10.5 K . The value of Knight shift would be almost constant from 4.2 to 270 K.

The field dependence of 59Co NMR in ferrimagnetic Er 1 - x Y x Co 3 was measured up to 8 T at 4.2 K. For pure ErCo 3 in fields perpendicular to the c axis the resonance frequencies change discontinuously between 2 and 3 T due to a field induced metamagnetic transition. The transition is characterized by rotations of Er and Co magnetic moments away from the easy c-axis. The angles between the Co moments and the c axis at x = 0.1 are obtained. The easy axis is found to be along the c axis for x = 0 and 0.1, and inclined from the c axis for x = 0.3 and 0.5.

We studied 59 Co nuclear magnetic resonance (NMR) in ErCo3 in magnetic fields up to B 0 =7 T and at temperatures from 4.2 to 130 K , including the metamagnetic transition at T M =100 K . The hyperfine field Bhf is negative only for the Co 18h-site, at 3b- and 6c-Co it is dominated by an unquenched angular momentum. The temperature dependence of the 18h-Co sublattice magnetization is smaller than deduced in a neutron study, with a first-order step at TM. A rapid decrease in NMR line intensity above ≈40 K may indicate a magnetic instability of 3b-Co.

Electrical resistivity and thermopower of Y1−xHoxCo2 alloys was measured from 2 to 300 K in magnetic fields up to 15 T . TC of HoCo2 increases with increasing magnetic field, however, the ordering temperature is not split into the ordering of Ho sub-lattice and the ordering of Co sub-lattice by the field contrary to the case of ErCo2.

In order to investigate the antiferromagnetic phase in Mn3Si with TN = 23 K microscopically, 55Mn NMR have been carried out in the temperature region between 2.2 and 17 K. The temperature dependences of spectrum and spin-lattice relaxation time T1 of 55Mn NMR have been measured. In the antiferromagnetic state, two different spectra corresponding to Mn(I) and Mn(II) sites are found in the resonance frequencies of 143.5 and 6.3 MHz, respectively, at 4.2 K. From these results, the internal magnetic fields on 55Mn(I) and 55Mn(II) nuclei are obtained to be 13.6 and 0.6 T, respectively. According to NMR results, a helical structure in Mn spin states is well explained compared with the transverse sinusoidal structure.

The spinel CuV2S4 exhibits two-step anomalies at about 92 K (Tt1) and 56 K (Tt2), reflecting the CDW state. In order to investigate the CDW state on V rich side in Cu(Ir1?xVx)2S4 microscopically, NMR measurements of 51V for Cu(Ir1?xVx)2S4 (x = 1.00, 0.98 and 0.95) have been carried out between 4.2 and 300 K. The line width of 51V for x = 1.00 is very narrow above Tt1 and become wider with decreasing x. For x = 1.00 and 0.98, the line width is suddenly broadened at Tt1 due to an electrical quadruple interaction between 51V nucleus and CDW charge modulation, but for x = 0.95, the line width is continuously increased around Tt1. The Knight shifts of 51V for x = 1.00, 0.98 and 0.95 show almost the same negative shift due to the influence of d-electrons above Tt1. At Tt1, the values of the Knight shift for x = 1.00 and 0.98 suddenly change to positive values, but for x = 0.95 continuously shifts to a positive one. The 1/T1T's of 51V for x = 1.00, 0.98 and 0.95 obey the Korringa law above Tt1. Below Tt1, the 1/T1T values of 51V for x = 1.00, 0.98 and 0.95 take constant values, which shows the Korringa law resulting from Pauli paramagnetic state.

We carried out an 121Sb nuclear magnetic resonance (NMR) measurement on CeOs4Sb12 to investigate its electric state. The precise temperature (T) dependence of the Knight shift was obtained by using an aligned powdered sample and NQR parameters. The T dependence of the Knight shift below 300 K can not be explained by the c-f hybridization gap model with 2D = 3000 K and 2Δ = 320 K obtained by the 1/T1. This result indicates that there is q-dependence in the gap. It was revealed that a ferromagnetic correlation develops with decreasing temperature below 50 K from an increase of the Knight shift. Considering this result and previous 1/T1 measurements, there are both ferromagnetic and antiferromagnetic fluctuations in CeOs4Sb12.

NMR measurements of 59 Co in ferrimagnetic ErCo3 have been carried out between 4.2 and 120 K in external fields up to 7 T . The zero-field powder spectrum at 4.2 K shows three resolved lines at 23, 65, and 96 MHz . In a field along the c-axis the two lower frequencies decrease with increasing field at 10.01 MHz/T , while the upper one increases at the same rate. The temperature dependence of the upper line gives strong indication that the Co-moment of this sublattice decreases discontinuously at the transition temperature 100 K .

Using the Fourier transform of the echo envelope, the proton line shapes, spin-lattice relaxation time, and spin-spin relaxation time have been measured in a (Ni0.36Nb0.24Zr0.40)90H10 glassy alloy at 1.83 T (∼78 MHz) and at temperatures between 1.8 and 300 K. First, the spectral line width decreases abruptly between 1.8 and 2.1 K. Next, it remains almost constant at 13 kHz up to ∼150 K. Finally, the line width decreases as the temperature increases from ∼150 to 300 K. The initial decrease in the spectral line width is ascribed to the distribution of the external field, which is caused by the penetration of vortices in the superconducting state. The subsequent leveling off in the spectral line width is ascribed to the dipole-dipole interaction between protons when hydrogen atoms are trapped into vacancies among the Zr-centered icosahedral Zr5Ni5Nb3 clusters. The final decrease in the spectral line width is ascribed to the motional narrowing of the width that is caused by the movement of hydrogen atoms. The...