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1Author    C. B. Azzoni, G. B. Parravicini, G. Samoggia, P. Ferloni, F. ParmigianiRequires cookie*
 Title    Electrical Instability in CuOj_ x : Possible Correlations with the CuO-based High Temperature Superconductors  
 Abstract    Physical properties of stoichiometric and non stoichiometric CuO are reported. The electrical conductivity has been measured on CuO pellets, sintered with the usual procedure for the prepara-tion of Y Ba-Cu O superconductors and then deoxygenated under a nitrogen flow. It is shown that oxygen deficient CuO pellets present abrupt and large resistivity drops as the temperature decreases below 230-200 K. Possible correlations between the electrical instability of oxygen defi-cient CuO and the high temperature superconductivity problem are discussed. 
  Reference    Z. Naturforsch. 45a, 790—794 (1990); received February 20 1990 
  Published    1990 
  Keywords    Cupric oxide, Superconductors, Electrical conductivity 
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 TEI-XML for    default:Reihe_A/45/ZNA-1990-45a-0790.pdf 
 Identifier    ZNA-1990-45a-0790 
 Volume    45 
2Author    A. A. Red 'kin, A. B. Salyulev, M. V. Smirnov, V. A. KhokhlovRequires cookie*
 Abstract    e n s ity a n d E le c tr ic a l C o n d u c tiv ity o f N a C l -C o C l 2 a n d N a C l -N i C l 2 M o lte n M ix tu r e s The density and electrical conductivity of cobalt and nickel dichlorides and their solutions in molten sodium chloride have been measured. The density was measured by a dilatometric method, and the electrical conductivity by an AC technique. The molar volume and equivalent conductance were calculated. 
  Reference    Z. Naturforsch. 50a, 998—1002 (1995); received July 29 1995 
  Published    1995 
  Keywords    Density, Electrical Conductivity, Molten Chlorides 
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 TEI-XML for    default:Reihe_A/50/ZNA-1995-50a-0998.pdf 
 Identifier    ZNA-1995-50a-0998 
 Volume    50 
3Author    A. A. Red 'kin, A. B. Salyulev, M. V. Smirnov, V. A. KhokhlovRequires cookie*
 Title    Density and Electrical Conductivity of Molten (2K, Fe)Cl 2 , (2K, Co)Cl 2 , and (2K, Ni)Cl 2  
 Abstract    The density and electrical conductivity of molten (2 K, Fe) Cl 2 , (2 K, Co) Cl 2 and (2 K, Ni) Cl 2 have been investigated. The density was measured by the maximum bubble pressure and dylatometric methods, the electrical conductivity by an AC technique. The molar volume and equivalent conduc-tance were calculated. 
  Reference    Z. Naturforsch. 52a, 420—424 (1997); received October 25 1996 
  Published    1997 
  Keywords    Molten chlorides, Density, Electrical conductivity 
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 TEI-XML for    default:Reihe_A/52/ZNA-1997-52a-0420.pdf 
 Identifier    ZNA-1997-52a-0420 
 Volume    52 
4Author    J. 0. Besenhard, H P Fritz, H. Möhwald, J J NickiRequires cookie*
 Title    Elektrochemische Intercalation und elektrische Leitfähigkeit von Graphitfasern Electrochemical Intercalation and Electrical Conductivity of Graphite Fibers  
 Abstract    Lamellar compounds of graphite fibers have been prepared by electrochemical inter-calation. The dependence of the electrical resistance on the intercalate concentration was determined by a quasi simultaneous method. A factor 30 decrease of the relative fiber resistance was obtained with fluorosulfuric acid. 
  Reference    Z. Naturforsch. 33b, 737—739 (1978); eingegangen am 14. April 1978 
  Published    1978 
  Keywords    Graphite Fiber, Intercalation, Electrical Conductivity 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0737.pdf 
 Identifier    ZNB-1978-33b-0737 
 Volume    33 
5Author    Kazuo Igarashi, KojiTajiri Tadashi Asahina, Mineo Kosaka, Yasuhiko Iwadata, Junichi MochinagaRequires cookie*
 Abstract    P r o p e r tie s o f K S C N -r ic h M o lte n N a S C N -K S C N M ix t u r e s For molten (Na, K)SCN mixtures with more than 50 mol% KSCN the molar volume V m, electri­ cal conductivity, x, refractive index n, surface tension y and heat capacity CP were measured in dependence of composition and temperature, y exhibited the minimum at ca. 70 mol% KSCN and Cp was 148 JK_I mol-1 in the range of 413 to 471 K. The electronic polarizabilities of the ions in the molten state were estimated by the semiclassical Clausius-Mossotti equation. 
  Reference    Z. Naturforsch. 46a, 540—544 (1991); received January 26 1991 
  Published    1991 
  Keywords    Molar volume, Electrical conductivity, Refractive index 
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 TEI-XML for    default:Reihe_A/46/ZNA-1991-46a-0540.pdf 
 Identifier    ZNA-1991-46a-0540 
 Volume    46 
6Author    Hiroyuki Ishida, Yoshihiro FurukawaRequires cookie*
 Title    Self-Diffusion in the Ionic Plastic Phase of (CH 3 ) 3 NHC10 4 Studied by *H NMR and Electrical Conductivity  
 Abstract    Spin-lattice relaxation times (7^) and spin-spin relaxation times (T 2) of 'H NMR and the electrical conductivity (er) of trimethylammonium Perchlorate were measured in the ionic plastic phase obtainable above 480 K. In this phase, both the cation and anion were revealed to perform self-diffusion. The activation energy (£ a) of the cationic diffusion was evaluated to be 55 ±4 and 50 + 4kJmol _1 from 7j and 'H 7 2 respectively, while E a of the anionic diffusion was 64 ±3 kJ mol" 1 from the electrical conductivity. 
  Reference    Z. Naturforsch. 51a, 83—86 (1996); received December 4 1995 
  Published    1996 
  Keywords    Ionic plastic phase Self-diffusion, Nuclear magnetic resonance, Electrical conductivity 
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 TEI-XML for    default:Reihe_A/51/ZNA-1996-51a-0083.pdf 
 Identifier    ZNA-1996-51a-0083 
 Volume    51 
7Author    W. OsakRequires cookie*
 Title    Charge Transport and Relaxation in Triglycine Sulphate (TGS)  
 Abstract    Charging currents, J-V characteristics and electron conductivity have been measured in triglycine sulphate along three crystallographic directions: a, b and c. The measurements have been taken in a wide temperature range between — 196°C and 80 °C. It is found that the charging currents have short relaxation times in the directions: a and c and a long relaxation time along the ferroelec-tric b axis. The J-V characteristics in the direction of the a and c axes have the shapes characteristic for linear dielectrics with space charge limited currents. The J-V characteristic for the b axis depends on the temperature: In the region of the phase transition the Fridkin-Kreher formula (J cc F 4/3) is satisfied; for low temperatures characteristic agrees with SCLC theory for linear dielectrics with Gaussian traps energy distribution. The d.c. conductivity along the c axis is much higher than along the a and b axes. In the investigated temperature range, the electrical conductivity has an activation character. For — 100°C < T < -193°C there is: <roc(l/T) exp(-E/kT). The activation energy depends both on the crystallographic direction and on the temperature-range. For low temperatures, T < — 100 °C, the activation energies are very small (of the order of a few hundreds eV). Subject classification: 72 (Electronic transport in condensed matter); 77 (Dielectrics, piezoelectrics and ferroelectrics and their properties). 
  Reference    Z. Naturforsch. 52a, 621—628 (1997); received February 17 1997 
  Published    1997 
  Keywords    Ferroelectrics, J-V characteristics, Electrical conductivity 
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 TEI-XML for    default:Reihe_A/52/ZNA-1997-52a-0621.pdf 
 Identifier    ZNA-1997-52a-0621 
 Volume    52 
8Author    Shin'. Ichi Ishimaru, Miho Yamauchi, Ryuichi IkedaRequires cookie*
 Title    Dynamics of Interlayer Cations in Tetramethylammonium-Saponite Studied by l H, 2 H NMR, and Electrical Conductivity Measurements  
 Abstract    We observed 'H and 2 H NMR spectra, 'H NMR spin-lattice relaxation times, and electrical con-ductivities of water-saturated and anhydrous tetramethylammonium(TMA)-saponites between 100 and 415 K. The very weakly bound cations produced narrow *H and 2 H NMR lines observed in both specimens down to 150 K. The temperature dependence of the 'H NMR spin-lattice relaxation times in the water-saturated and anhydrous samples gave asymmetric minima attributable to the heteroge-neous overall rotation and self-diffusion of the cations. The inhomogeneity of the cationic motions in the anhydrous TMA-saponite was greater than in the water-saturated one. From measurements of the electrical conductivity of anhydrous TMA-saponite a large anisotropic cation-diffusivity was concluded. 
  Reference    Z. Naturforsch. 53a, 903—908 (1998); received June 2 1998 
  Published    1998 
  Keywords    Saponite, Cation Dynamics, NMR, Electrical Conductivity, Intercalation 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0903.pdf 
 Identifier    ZNA-1998-53a-0903 
 Volume    53 
9Author    C. B. Azzoni, M. C. Mozzati, A. Paleari, M. Bini, D. Capsoni, G. Chiodelli, V. MassarottiRequires cookie*
 Title    Stoichiometry Effects on the Electrical Conductivity of Lithium-Manganese Spinels  
 Abstract    The electrical conductivity of lithium-manganese spinels is analyzed in samples with different starting Li cationic fraction x. Li-rich spinels, resulting from Li-Mn substitution around the stoi-chiometric value (x= 0.333), show conductivity values higher than that observed in stoichiometric LiMn 2 0 4 . Besides, a conductivity drop, associated with a structural phase transition at about 290 K in LiMn 2 0 4 , progressively disappears by decreasing x, while it is absent in Li-rich samples. Stoi-chiometry effects on the concentration of charge carriers and on the available sites for the hopping transport process are evaluated, as well as the effects due to coexisting insulating phases. The role of the Jahn-Teller effect on the conductivity behaviour of stoichiometric and Li-poor spinels is also considered. 
  Reference    Z. Naturforsch. 54a, 579—584 (1999); received May 15 1999 
  Published    1999 
  Keywords    Electrical Conductivity, Lithium Manganese Oxides, LiMn 2 0 4 
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 TEI-XML for    default:Reihe_A/54/ZNA-1999-54a-0579.pdf 
 Identifier    ZNA-1999-54a-0579 
 Volume    54 
10Author    Alina Wojakowska, Agata GorniakRequires cookie*
 Title    The Electrical Conductivity of Molten (Ag, C d 1/2)B r  
 Abstract    The electrical conductivity of molten (Ag, Cd1/2)Br has been determined as a function of temperature in the whole range of compositions. The resulting activation energy values and the conductivity isotherm at 850 K are compared with those of the system (Ag, C d^^C l. 
  Reference    Z. Naturforsch. 56a, 751—753 (2001); received August 20 2001 
  Published    2001 
  Keywords    AgBr, CdBr2, Molten Salts, Electrical Conductivity 
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 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0751.pdf 
 Identifier    ZNA-2001-56a-0751 
 Volume    56 
11Author    Rolf Appel, Werner Michel, Wolfgang MorbachRequires cookie*
 Title    Ein neues Verfahren zur Bestimmung kleinster Mengen H20 mittels Ph3P und CC14 [1] A New Way to Determine Smallest Amounts of H20 by Means of Ph3P and CCI4 [1]  
 Abstract    A new and easier method of water determination in numerous organic solvents is founded on the measurement of the electrical conductivity in the system PI13P/CCI4/H2O, that is characterised by a typical maximum minimum pattern. The time interval up to the registration of the well-defined minimum is proportional to the amount of water which can be determined down to concentrations of 10 _3 %. 
  Reference    Z. Naturforsch. 33b, 1205—1207 (1978); eingegangen am 5. Juni 1978 
  Published    1978 
  Keywords    Electrical Conductivity, Water Determination, Organic Solvents 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-1205.pdf 
 Identifier    ZNB-1978-33b-1205 
 Volume    33 
12Author    Koji Yamada, Takashi Matsui, Tomoko Tsuritani, Tsutomu Okuda, Sumio IchibaRequires cookie*
 Title    I-NQR, 119 Sn Mössbauer Effect, and Electrical Conductivity of MSnI 3 (M = K, NH 4 , Rb, Cs, and CH 3 NH 3 )  
 Abstract    In a series of MSnI 3 compounds (M = K, NH 4 , Rb, Cs, CH 3 NH 3) two types of coordination around the central Sn(II) were found by 127 I-NQR and powder X-ray diffraction techniques. They are square pyramidal (for M = NH 4 , Rb) and octahedral (for M = CH 3 NH 3). CsSnI 3 , on the other hand, showed a drastic structural change of the anion at 425 K from a square pyramid to a regular octahedron. Associated with this phase transition, the electrical conductivity increased from 4xlO~ 3 Scm _1 to about 10 2 S cm" 1 . This metallic modification was characterized by 127 I-NQR and 119 Sn Mössbauer spectroscopy. 
  Reference    Z. Naturforsch. 45a, 307—312 (1990); received August 24 1989 in revised form October 28 1989 
  Published    1990 
  Keywords    NQR, Mössbauer effect, Perovskite compound, Phase transition, Electrical conductivity 
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 TEI-XML for    default:Reihe_A/45/ZNA-1990-45a-0307.pdf 
 Identifier    ZNA-1990-45a-0307 
 Volume    45 
13Author    Wolfgang Jeitschko, Jörg Wallinda, MartinV. Dewalsky, Ulrich WortmannRequires cookie*
 Title    Preparation, Properties, and Structure of the Polyphosphides VM4P16, NbNi4P16, and WNi4P16  
 Abstract    The title compounds were prepared by reacting powders of the binary transition metal alloys with phosphorus in a tin melt. They crystallize with a monoclinic structure of space group C 2/c, which was determined from single-crystal X-ray data; VNi4P16: a = 1956.0(3), b = 565.9(1), c = 1106.6(2) pm, ß = 100.99(1)°, R -0.020 for 1904 structure factors and 97 variable parameters; NbNi4P16: a = 1973.0(3), b = 571.2(3), c = 1117.2(2) pm, ß = 100.74(1)°, R = 0.023 for 2431 F-values and 97 variables; WNi4P16: a = 1964.2(3), b = 568.3(2), c = 1109.3(2) pm,/? = 101.04(2)°, R = 0.031 for 371 F-values and 43 variables. The T atoms (T = V, Nb, W) have eight P neighbors, which form a slightly distorted square antiprism, and the Ni atoms have appro­ ximately octahedral P coordination. The P atoms form novel P8 units, which consist of 6 -mem-bered rings with a P2 side chain. Chemical bonding is discussed on the basis of classical two-electron bonds. A comparison of the interatomic distances suggests that the Fermi level cuts through a band formed by antibonding nickel-phosphorus states. A band structure is propos­ ed, which also rationalizes the metallic conductivity and the Pauli paramagnetism of the com­ pounds. 
  Reference    Z. Naturforsch. 48b, 1774—1780 (1993); received July 291993 
  Published    1993 
  Keywords    Crystal Structure, Magnetic Properties, Electrical Conductivity, Chemical Bonding, Transition Metal Polyphosphides 
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 TEI-XML for    default:Reihe_B/48/ZNB-1993-48b-1774.pdf 
 Identifier    ZNB-1993-48b-1774 
 Volume    48 
14Author    Eberhard Bothe, G. Ali, Ureshi, D. Ietrich, S. Ch, Lte-F Ro, H. Lin DRequires cookie*
 Title    Rate of OH Radical Induced Strand Break Formation in Single Stranded DNA under Anoxic Conditions. An Investigation in Aqueous Solutions Using Conductivity Methods  
 Abstract    Single stranded D N A (ssD N A) in aqueous N 20-satu rated solution was pulse-irradiated with electrons or irradiated under steady-state conditions with 60Co-y rays. The conductivity increase after irradiation was measured as a function o f concentration, pH, temperature, metal cation content and additives. The conductivity increase could be shown to be due to the release o f associated counterions (N a+ or H+) as a result o f the formation o f chain breaks. At 28 mg I-1 D N A ~ 8 sodium ions are liberated per 100 eV absorbed energy (G (N a +) = 8.3). On the basis o f G value for single-strand breaks (ssb) o f G(ssb) = 0.55, it is calculated that 8.3/0.55 = 15 sodium ions per strand break are set free. The release o f N a+ monitored by 23N a-N M R at pH 7 as a function o f dose corresponds to that o f the conductivity increase. The rate o f the conductivity increase does not depend on d ose/p u lse (range 2 -2 0 J kg-1) and shows at least two components. The rate constant o f the fast and dom inant com ponent is constant above pH 8.5 (A: = 38 s— 1, 20 °C) and increases linearly with proton concentration below pH 7. Values o f 13kcal/m ol for the activation energy and 5 x 10" s_1 for the frequency factor were obtained at pH 7.3. Addition o f p-benzoquinone (pBQ) increases the rate constant o f the fast component proportionally to the concentration o f pBQ. From these results the rate-determining step o f the fast conductivity increase is concluded to be the splitting o f D N A radicals. The pH dependence and the m agnitude o f the activation energy agree with results from low molecular weight model com pounds for the C-4' m echanism ; this m echanism involves a heterolytic splitting o f the phosphoric acid ester bond starting from the 4' radical o f D N A . 
  Reference    Z. Naturforsch. 38c, 1030—1042 (1983); received Septem ber 19 1983 
  Published    1983 
  Keywords    DNA, Formation o f Strand Breaks, Electrical Conductivity, Pulse R adiolysis, Rate Constants 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-1030.pdf 
 Identifier    ZNC-1983-38c-1030 
 Volume    38 
15Author    Masahiko Matsumiya, Ryuzo Takagi3Requires cookie*
 Title    Molecular Dynamics Simulation of the Internal Mobilities in Molten (D y ^ K ) Cl  
 Abstract    Molecular dynamics simulations have been performed on molten (Dyi/3,K)C1 at 1093 K in order to compare the calculated self-exchange velocity (SEV), self-diffusion coefficient (D) and electrical con­ ductivity with the corresponding experimental results. It was found that SEV, v, and D of potassium de­ crease with increasing concentration of dysprosium, as expected from the internal mobility, b. The decrease of bK, vK, and DK are ascribed to the tranquilization effect by Dy3+ which strongly inter­ acts with CP. On the contrary, bDy, vDy, and £>Dy increase with increasing concentration of Dy3+. This may be attributed to the stronger association of Dy3+ with Cl~ due to the enhanced charge asym­ metry of the two cations neighboring to the Cl-. In addition, the sequence of the calculated SEV's, D's and electrical conductivities for the various compositions were consistent with those of the referred ex­ perimental results. 
  Reference    Z. Naturforsch. 56a, 273—278 (2001); received January 22 2001 
  Published    2001 
  Keywords    Electrical Conductivity, Internal Cation Mobility, Molten DyCl3-KCl, Molecular Dynam­ ics Simulation, Self-exchange Velocity, Self-diffusion Coefficient 
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 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0273.pdf 
 Identifier    ZNA-2001-56a-0273 
 Volume    56