Gustavo Tavizon

Structure and magnetic properties of the weak ferromagnet Sr2-xLaxIrO4

The 5d electron-based Sr2?xLaxIrO4 system (0?x?0.2) has been synthesized by a solid-state route. The x = 0 composition is a nonmetallic weak ferromagnet with a Curie temperature at about 240?K. The crystal structure behaviour and magnetic properties exhibited by this Sr2?xLaxIrO4 system can be explained on the basis of the extended character of the 5d electrons of the Ir cation and its valence states. Rietveld analysis of x-ray powder diffraction on Sr2IrO4 agrees well with previous structural neutron experiments. Furthermore, density functional theory (DFT) calculations predict that I41/acd represents a more stable crystal structure than K2NiF4 (I4/mmm). Electrical resistivity and magnetic properties of Sr2?xLaxIrO4 are strongly dependent on the Ir3+ content. The Sr2?xLaxIrO4 magnetic behaviour in the range of 2?240?K can be ascribed to a weak ferromagnet, produced by an array of canted antiferromagnetically ordered Ir4+ magnetic moments.

Structure and Electronic Conductivity of Reduced Gd-Doped CeO2

In this work we studied the electronic conductivity of highly reduced polycrystalline Ce 0.8 Gd 0.2 O 1.9-8 at low temperatures (25-100°C). The specimens were treated at a variety of reducing conditions at high temperature and then quenched. The nonstoichiometry of the samples was estimated by thermogravimetry. We showed that a high reduction level leads to high conductivity and low activation energy. We estimated an activation energy change from 0.60 to 0.38 eV in going from slightly to heavily reduced. An X-ray diffraction study of this nonstoichiometric material showed that the reduction is accompanied by an increase of a secondary bixbyite phase. If the quenched structures studied in this work represent the high-temperature phases, then our results are in contradiction to models that consider that the fluorite structure of CeO 2 is highly tolerant to reduction remaining as a single phase.

Magnetic behavior of the Bi2−ySryIr2O7 pyrochlore solid solution

The temperature dependence of magnetic susceptibility of the Bi

Anisotropic normal-state properties of the MgB2 superconductor

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The loss of anisotropy in MgB2 with Sc substitution and its relation with the critical temperature

Sr

Effects of static magnetic fields on the enteropathogenic Escherichia coli

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Synthesis and Crystal Structure of Oxygen-deficient Bilayer Ruthenate Sr3Ru2O7–δ

Ir

Microstructure and electrical transport in nano-grain sized Ce0.9Gd0.1O2−δ ceramics

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Rice-ball structures of iron–benzene clusters, Fe4–(C6H6)m, m ⩽ 3. A density functional study

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Structural and Ionic Conduction Analyses of the Na2(Zr1–xAlx)O3–x/2 Solid Solution, During the CO2 Chemisorption Process

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