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A quasi 1-dimensional carbon crystal has been synthesized by quenching of high temperature carbon gas on a room temperature metallic substrate. The structure is hexagonal and the sizes of the unit cell are 1.193 nm along the a-direction and 1.62 nm along the c-dirdtion. A parallel array of charbon chains is formed along the c-axis. The array is made of a triangular lattice of which inter-chain distance is 0.344 nm and the mean inter-atomic C-C distance along the chain is 0.133 nm. The crystal is half transparent in the visible region and has its specific weight as small as 1.46 g/cm3. In order to test the possibility of intercalation, reactions with potassium, sodium and iodine have been performed. In every reaction, the material has converted from an insulator to a conductor.

The Hall coefficient, resistivity and Seebeck coefficient of Ag/sub 2/Te have been measured over the temperature range from 100 to 300 K. These results indicate that the compound is highly degenerate. The effect of the magnetic field has also been studied up to 1.2 T. The size of the transversal magnetoresistance with a magnetic field of 1.2 T is about 15% at lower temperatures, but it decreases to about 5% at higher temperatures. The effect of the magnetic field on the Seebeck coefficient is on the other hand more intense at higher than at lower temperatures. The experimental results have been analyzed by numerically solving the Boltzmann transport equation.

We present some results on thermoelectrical properties of several levels of Sn doped Bi/sub 88/Sb/sub 12/ single crystal. Resistivity and Seebeck coefficient are measured between 100 and 300 K by applying magnetic field 0-1.2 T. Based on experimental results, these values have a strong dependence on magnetic field and the dependence is the same as that of the Sn doping effect.

The establishment of intrinsic semiconductivity of tellurium in the 1940s to 50s and the discovery of semiconductivity in the solid solution Bi-Sb alloy system in the 1950s and 60s are described in relation to thermoelectricity. The development of Peltier cooling devices using the Bi/sub 2/Te/sub 3/ family is also mentioned. As with recent studies, the merits of applying magnetic fields to thermoelectric materials are examined. Bi/sub 88/Sb/sub 12/ and the same alloy doped with various amounts of Sn were exposed to a magnetic field of 0.8 tesla. The magnetic field had a remarkable influence on the alloys; sometimes the Seebeck coefficient was enhanced by more than 50% and the sign of the Seebeck coefficient was changed. An application of a gradient magnetic field on a thermoelectric rod specimen possibly substitutes FGM. The Ettingshausen temperature gradient on Bi/sub 88/Sb/sub 12/ was also studied.

A Peltier current lead was proposed to reduce heat leak from the current lead. We studied two experiments as the principle of the Peltier current lead. In the first experiment, we measured Peltier cooling temperatures and resistivity of the semiconductors and copper lead; the purpose of this was for comparison with the second experiment. In the second experiment, the high temperature superconductor (HTS) was cooling down for Peltier effect at 77 K. Those temperatures were small, because the figure of merit of semiconductors, BiSb (n-type) and BiTe (p-type) were not enough values to be cooling HTS.

Galvanomagnetic and thermomagnetic effects were studied in order to serve the solid state energy conversion. A possible merit of the use of magnetic field in these effect is obvious because the Seebeck emf (longitudinal Nernst-Ettingshausen effect) or Peltier cooling (Nernst effect) could be enhanced under the magnetic field. Moreover, the Ettingshausen effect generates a temperature gradient under the magnetic field. Such three effects were studied experimentally. On a Bi/Sb sample, the temperature difference due to the Ettingshausen effect for the sample width of 10 mm, and the current density of 1 A/mm/sup 2/ was 23 K at the ambient temperature of 100 K and in the magnetic field of 1.0 tesla. The Nernst temperature difference under the relevant condition was 15.4K for 10 mm length.

Peltier current lead was proposed to reduce heat leak from the current lead. The temperature of the hot side of semiconductors was kept to be a room temperature and the liquid nitrogen was used to cool the system in the experiment. The experiment confirmed the principle of the Peltier current lead, and the reduction of the heat leak is calculated to be 30% for the liquid helium system and 40% for the liquid nitrogen system. We also proposed a new current lead system which is composed of semiconductors and high temperature superconducting material (HTS). This idea bases on the functionally gradient material (FGM), and the HTS is connected to the semiconductor directly. The temperature of the hot side of semiconductor is kept to be the liquid nitrogen temperature, the temperature of HTS can be expected to be lower than 77 K. Therefore, we can expect high current capacity of the HTS and/or high stability of the HTS. We use BiSb as a N-type semiconductor and BiTe as a P-type semiconductor in the experiment, and the temperature of the cold side of the semiconductor is 73 K in this experiment.

Alkali metal atoms and a halogen molecule have been intercalated in quasi one dimensional carbon crystal “carbolite”. Carbolite was synthesized by quenching carbon are on copper plate or sapphire plate at the room temperature. Linear carbon chains were generated by quenching and arrayed in a direction perpendicular to the substrate plate. The triangularly distributed array was a coarse aggregation of chains by the van der Waals force. Therefore it was expected that the intercalation of, for example, an alkali metal atom was possible similarly to the graphite intercalation. The in-situ change of the electrical resistance of intercalated carbolite by the heat treatment has been investigated. The temperature dependence of the resistance has shown a thermal activation type.

Kinetics of the stage transition in electrolytic intercalation of sulphuric acid in graphite has been investigated by in situ observation of the diffraction patterns of segments of different distance from the acid reservoir. By comparing the same pattern in different positions in different times, the propagation velocities of stage boundaries have been measured. Their dependencies on current and height fit the “sliding” model of intercalation sheets.

We present a model of the Fermi surface for stage 2 SbCl 5 GIC consisting seven undulating cylinders extending in the k c -direction: three and four of them are pockets of electrons and of holes, respectively. Slight undulations on some of these cylinders are found by the measurements both of induced torque and transverse magnetoresistance showing an evidence of open orbits extending in the k c -direction, i.e., three dimensionality of the FS. As many as forty frequency branches are observed in dHvA type measurements which are explained by the model resulting from the C−14×14 in-plane superlattice truncations of two 2D hole FSs proposed by Blinowski et al. by an approximation of neglecting the undulation of the FSs. Effect of the in-plane structural phase transition at ∼230 K from liquid to IC−√39×√39 on the FS has been reported. Also sample dependence of dHvA oscillations arising from differences of host materials and of synthesis temperatures has been reported. Evidence of open orbits extending in the k c -direction is found in the case of the donor type compound, C 8 K. Topology of the FS is discussed referring to the results of dHvA experiments and the theoretical model presented here.

Magnetostrictive strain in pristine highly oriented pyrolytic graphite (HOPG) and SbCl5-graphite intercalation compounds (GIC's) has been studied in steady magnetic fields up to 10 tesla, including the quantum oscillation effect. Fourier spectra of the magneto-oscillations are stage dependent and in agreement with those reported by Takahashi et al. For pristine HOPG, the monotonie component of the longitudinal magnetostrictive strain (LMS) parallel to the c-axis is found to be negative and to increase in magnitude with increasing width at half maximum intensity of the (002) line of X-ray diffraction. This result is explained qualitatively within the framework of the Keyes theory by considering the reduction of the static shear modulus of graphite due to the displacement of basal-plane dislocations. The stress coefficient of the majority hole Fermi surface is determined as δ In S h δσ [0001] = 0.034 ± 0.006 kbar − by using magnetostriction and torque de Haas-van Alphen measurements.

The de Haas-van Alphen effect has been measured in single crystals of ytterbium at 1.2°K in magnetic fields up to 116 koe. The crystals, prepared by distillation, were found to be in either a hexagonal or a f.c.c. phase at room temperature but only in the hexagonal phase after a cooling cycle to 1.2°K. The hexagonal phase is attributed to a hexagonal-close-packed structure reported previously for ytterbium at temperatures above 260°C. De Haas-van Alphen frequencies for the h.c.p. principal planes and symmetry directions are reported. These results indicate hyperbolic sections of the Fermi surface of h.c.p. ytterbium.

By using a condenser bank of the capacity 9000 μF and the working voltage 3.3 kV, magnetic fields higher than 400 kOe have been produced in a pulse form, the duration of which is about 1 ms. In order to avoid the mechanical breakdown of the coil, various types of coils including a toroidal transformer-type device have been constructed. Using these fields, various experiments have been performed. Magnetization parallel to the c axis (hard axis) of the Tb single crystal in the magnetic fields of 200 to 620 kOe at 77°K caused an appreciable lattice elongation parallel to the c axis, which resulted in an appearance of the local anisotropy with its hard axis perpendicular to the c axis. Measurements of the magnetoresistance effect of dilute alloys and the high field susceptibility of ferromagnets are also described.

The superconducting transition temperature in quenced metallic indium antimonide depends on the treating pressure and temperature. It increases from 1.6°K to 5.1°K with increasing pressure and decreasing temperature. It is associated with the density of states of electrons.

Superconductivity has been observed in metallic indium antimonide which is obtained by quenching at 170 kbar (above lead transition) and at room temperature to 77°K and 1 bar. The superconducting transition occurs at 4.8°K.

The initial pressure dependence up to 4.2 kbar has been measured on the hole portion of the Fermi surface of antimony by the De Haas-Van Alphen effect. The cross sectional area of the hole ellipsoids exhibits a nearly isotropic increase with pressure at an initial rate given by dln S h /d p = (7 ± 1) × 10 −3 /kbar.

The magnetoresistance of Yb at 1.3°K and in magnetic fields up to 20 kOe is reported. The Fermi surface of Yb supports no open orbits and the single-OPW model of Yb is not adequate. It is suggested that the Fermi surface is closed and occupies a small volume.

The de Haas-van Alphen effect has been observed on a ytterbium single crystal. Two kinds of oscillations are found. One of these has the value of oscillation period of 2.5 to 6.0 × 10−6Oe−1 and the other has 5.5 to 7.0 × 10−7Oe−1.

Magneto-thermal oscillation in arsenic has been observed at 1°K as well as in bismuth and antimony. The oscillation has a period of 5.9 × 10 -7 Oe -1 and shows a sharp rise of amplitude at about 20 kOe.