摘要:

AbstractWe have studied the magnetic properties of the C14 Laves phase Ti0.40Mn0.60(homogeneity range from Ti0.33Mn0.67to Ti0.45Mn0.55), of the p phase Ti0.46Mn0.54, and of the ϕ phase Ti0.48Mn0.52, as well as the magnetic properties of their hydrides. The investigation includes susceptibility measurements in the temperature range 5 to 360 K, magnetization measurements between 4.2 K and 250 K with fields up to 7.2 T, and Mössbauer effect measurements on57Fe doped samples at 4.2 K and 295 K. Additionally, low temperature heat capacity measurements have been performed. While the Ti – Mn intermetallic C14, ρ and ϕ phases themselves are paramagnetic with susceptibilities independent of temperature, their hydrides are ferromagnetic with Curie temperatures of about 213 K, 87 and 155 K, respectively. The ρ and ϕ phase hydrides possess a weak itinerant ferromagnetism, whereas the ferromagnetism of the C14 Laves phase hydride is of a more localized type. The susceptibilities aboveTcconsist of Curie Weiss terms and large temperature independent contributions. The non‐symmetric quadrupole split Mössbauer spectrum at room temperature indicates a distortion of a fraction of the tetrahedrons in the uncharged Ti0.40Mn0.60Laves phase which is removed by hydrogenation. The onset of ferromagnetism in the Ti – Mn ternary hydrides is due to the volume expansion which causes a narrowing of the d bands and thus increases the density of states at the Fermi level upon h

ISSN:0005-9021    

DOI:10.1002/bbpc.19830870113

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1983

数据来源: WILEY

摘要:

AbstractThe electrical conductivity, the thermoelectric power and the magnetic susceptibility of molten Tl + CuTlSe2mixtures have been measured up to 950°C. These mixtures exhibit a sharp decrease in electrical conductivity and a change in sign of thermoelectric power around the stoichiometric composition CuTl3Se2. Measurements of magnetic susceptibility also indicate a marked anomaly at this composition. These electronic properties for molten Tl + CuTlSe2mixtures are discussed in the light of current transport theories employed in the amorphous and liquid semiconductors

ISSN:0005-9021    

DOI:10.1002/bbpc.19830870114

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1983

数据来源: WILEY

摘要:

AbstractMarked differences in laser action (1.315 μm) following flash photolysis of CF3I‐inert gas mixtures were observed. Through the measurement of optical gain and considering the contribution to line broadening, collisional relaxation rate constants were obtained. Using another iodine source, i.e. C2F5I experimental results showed no significant differenc

ISSN:0005-9021    

DOI:10.1002/bbpc.19830870115

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1983

数据来源: WILEY

摘要:

AbstractThe quantum yield of photoelectrons, emitted from rhodamine B layers, which were adsorbed on cleaved faces of ionic crystals and on polished faces of amorphous quartz, has served to estimate the effective densities of occupied dye states in a small energy range below the vacuum level. For NaCl(100), RbCl(100), and calcite (1010) substrates the energy distributions of these states are very similar. If the substrate is amorphous quartz, the density of dye states in the investigated energy range is negligible in comparison to that on the ionic crystals. Assumptions are made concerning the possible origin of the relatively high density of dye states generated on ionic crystals.

ISSN:0005-9021    

DOI:10.1002/bbpc.19830870116

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1983

数据来源: WILEY

摘要:

AbstractElectrochemical nitric acid reduction has been investigated on graphite and titanium electrodes obtaining current‐potential‐curves, current‐time‐curves and applying electrochemical mass spectrometry for product analysis. Integral current efficiencies and selectivities for the various products has been determined. On graphite at low reduction potentials only NO is formed. At potentials where thermodynamically hydrogen evolution is possible the main products are H2, NO, N2O, and NH 4+. Under these conditions the reduction is catalysed by Cu2+, Ag+, and Pb2+‐ions which were deposited at the base electrode. These metals strongly influence the product distribution. A general reaction scheme is proposed, and the various electrocatalytic effects ar

ISSN:0005-9021    

DOI:10.1002/bbpc.19830870117

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1983

数据来源: WILEY

ISSN:0005-9021    

DOI:10.1002/bbpc.19830870118

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1983

数据来源: WILEY

ISSN:0005-9021    

DOI:10.1002/bbpc.19830870121

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1983

数据来源: WILEY

ISSN:0005-9021    

DOI:10.1002/bbpc.19830870123

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1983

数据来源: WILEY

ISSN:0005-9021    

DOI:10.1002/bbpc.19830870124

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1983

数据来源: WILEY

ISSN:0005-9021    

DOI:10.1002/bbpc.19830870101

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1983

数据来源: WILEY