Stoichiometrically adjusted antimony triselenide and antimony tritelluride semiconductors were carefully prepared for the first time. Numerous measurements were carried out, involving X-ray diffraction analysis, true density, thermogravimetric analysis and the temperature-dependence of the magnetic susceptibility. The results obtained indicated that antimony triselenide and antimony tritelluride polycrystals possess mass susceptibilities of −0.361×10−6 and −0.386×10−6 C.G.S., respectively. The results are discussed on the basis of electronegativity difference, partial ionicity of the bond, and bond strength.
Authors:P. K. Sinhamahapatra and S. K. Bhattacharyya
Thermal characteristics of the vanadates of zinc, manganese and silver have been studied by DTA and TG techniques and the different transition products thus obtained have been characterised by IR, X-ray diffraction and magnetic susceptibility data. Chemical analyses indicate the following compositions of these vanadates: (1) Zn2V2O7.5H2O, (2) Zn3(VO4)2.3H2O, (3) Mn(VO3)2.2H2O and (4) Ag3VO4. The DTA curves indicate that zinc pyrovanadate undergoes endothermic changes at 110–195, 265, 365, 440, 660° and one exothermic change at 485°. This system is diamagnetic which becomes completely paramagnetic after 660°. Zinc orthovanadate exhibits a number of endothermic peaks at 300, 470, 700, 815 and 930° respectively. This system is feebly paramagnetic and retains this property up to 930°. Manganese metavanadate undergoes endothermic changes at 240, 280–590, 830 and 880° respectively. This vanadate is paramagnetic and paramagnetism increases appreciably at 590° and remains constant up 830°. Silver orthovanadate exhibits three endothermic changes at 180, 455 and 640°, respectively.
Authors:T. Tsuji, Y. Yamamura, H. Watanabe, K. Saito, and M. Sorai
The heat capacities and magnetic susceptibilities of powdered samples of FexNbS2 (x=0.14, 0.21 and 0.30) were measured at temperatures from 8 to 303 K and from 5 to 300 K, respectively. For Fe0.14NbS2, the magnetic susceptibility exhibited an anomaly as a shoulder at about 57 K, but no heat capacity anomaly was observed at this temperature, indicating the appearance of a spin-glass state. Anomalies in the heat capacity for FexNbS2 (x=0.21 and 0.30) occurred at 100.5 and 45.0 K, respectively, where the magnetic susceptibility displayed a maximum, corresponding to an antiferro-paramagnetic phase transition. The electronic state of the iron atom is discussed on the basis of entropy analysis.
Three major domal structures are trending northeast-southwest directions prevailed at El-Hasana area, northern part of Sinai Peninsula. These structures and their altered rock constituents attracted us to study these formations from geophysical view. The main target of this work is to establish the relation between these structures and Syrian Arc Tectonic System (SATS) prevailed at the studied area. The investigations were carried out using land magnetic survey, aeromagnetic, gravity and laboratory measurements.An intensive analysis using tectonic trend analysis and, 3D Euler deconvolution with different coefficients were applied to the potential field data. Also, cross-sections Euler deconvolution, Werner deconvolution and radial power spectrum have been applied. The results illustrate that most prevailed tectonics that could forming these anticlines are trending at N 35°–65° E direction which related to the Syrian tectonics (SATS) direction. The depth to the basement rocks ranges between 2 km at the southern parts to 2.3 km at the northern parts of the studied area.The magnetic susceptibility map was constructed using laboratory measurements for more than 120 collected rock samples along the surveyed area. The average values range between 0.7 × 10
to 1 × 10
SI for limestone samples, whereas the sandstone varies between 1 × 10
to 1.5 × 10
SI unit. The results show that the magnetic values are higher for the rock samples picked along the anticlinal structures.
Four sulphato and nitrato complexes of cerium(IV),viz. (NH4)4Ce(SO4)4·2H2O (1), (NH4)2Ce(SO4)3 (2), (NH4)2Ce(NO3)6 (3) and Cs2Ce(NO3)6 (4) were studied by simultaneous TG/DTA under various experimental conditions in order to establish their decomposition mechanism
and to compare the results with the literature data which have been reviewed. In the case of the ammonium compounds (1, 2 and3) the decompositions are accompanied by changes in the oxidation state of cerium; the presence of Ce(III) and Ce(IV) were
studied byex situ magnetic susceptibility and XPS measurements. The crystal structure of (1) was determined as well. It forms monoclinic crystals with space groupP21/c; the parameters of the unit cell are:a=12.638(18) Å,b=11.362(10) Å,c=13.607(11) Å, β=110.17(9)°,V=1834.05 Å3.
Magnetic susceptibility and heat capacity due to spin-state excitations in LaCoO3 were analyzed with an irregular solution model composed of Co3+ ions in the low-spin ground state and in the high-spin excited state. An energy-levels diagram proposed by Ropka and Radvanskii
 was used for the high-spin excited state. This analysis showed that the entropy of mixing is less than that of ideal solutions
and the enthalpy of mixing is negative, indicating that the high-spin Co ions are arranged as far apart as possible.
Authors:M. Minohara, K. Tozaki, H. Hayashi, and H. Inaba
The melting transition of Ga and In was measured
by using a nW-stabilized differential scanning calorimeter working in a magnetic
bore. The magnetic effect on the thermometer was about 18 mK at 5 T, which
was corrected for the measurement of the magnetic effect on the melting transition
of Ga and In. The melting temperatures of Ga and In with the magnetic field
of 5 T were obtained to be 8.3 and 10.2 mK, respectively higher than those
without the magnetic field. These results show that the solid phase to be
relatively more stable under the magnetic field. The calculated temperature
shifts of the melting transition due to the magnetic field using the magneto-Clapeyron
equation and the reference data of magnetic susceptibility were negative values
for both Ga and In, being contradictory to the experimental results.