M. C. Prestgard; G. P. Siegel; A. Tiwari
Abstract
In this article we have reviewed the role of oxides in spintronics research, and specifically how these materials stand to further improve the efficiencies and capabilities of spin injection for active spintronic device development. The use of oxides in spintronics is advantageous in that they are stable ...
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In this article we have reviewed the role of oxides in spintronics research, and specifically how these materials stand to further improve the efficiencies and capabilities of spin injection for active spintronic device development. The use of oxides in spintronics is advantageous in that they are stable in air, can be easily modified, and can possess a wide variety of properties which are beneficial to spintronics applications. This paper delineates the progression of spintronics and shows how applying oxide systems, in the form of half-metallic LaSrMnO3, the diluted magnetic semiconductor ZnO:Co, and diluted magnetic dielectrics CeO2:Co and Sm2O3:Co, has influenced and improved spintronics capabilities. An outline of the future potential for oxides in the realm of organic spintronic devices is also given
P. Kumari; R. Rai; A. L. Kholkin; A. Tiwari
Abstract
The ferroelectric Ca doped (Ba0.9575La0.04X0.0025) (Ti0.815Mn0.0025Nb0.0025Zr0.18)0.99O3 was prepared by a high-temperature solid state reaction technique. For the understanding of the electrical and dielectric property, the relation between the crystal structures, electrical transition and ferroelectric ...
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The ferroelectric Ca doped (Ba0.9575La0.04X0.0025) (Ti0.815Mn0.0025Nb0.0025Zr0.18)0.99O3 was prepared by a high-temperature solid state reaction technique. For the understanding of the electrical and dielectric property, the relation between the crystal structures, electrical transition and ferroelectric transitions with increasing temperature ( –160 to 35°C) have been analyzed. X- ray diffraction analysis of the powders suggests the formation of a single-phase material with monoclinic structure. Capacitance and tanδ of the specimens were measured in the temperature range from -160 to 35°Cat frequencies 1 kHz – 1 MHz. Detailed studies of dielectric and electrical properties indicate that the Curie temperature shifted to higher temperature with the increase in frequency. Moreover, the dielectric maxima dropped down rapidly initially and the dielectric peaks became extremely broad. The AC conductivity increases with increase in frequency. The low value of activation energy obtained for the ceramic samples could be attributed to the influence of electronic contribution to the conductivity.
A. P. Mishra; A. Tiwari; Rajendra K. Jain
Abstract
The coordination complexes of Co(II), Ni(II) and Cu(II) derived from 2-thiophenecarboxylidene-3-chloro-4-fluoroaniline (TCC) and 2-thiophenecarboxylidene-4-fluoroaniline (TCF) have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, ...
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The coordination complexes of Co(II), Ni(II) and Cu(II) derived from 2-thiophenecarboxylidene-3-chloro-4-fluoroaniline (TCC) and 2-thiophenecarboxylidene-4-fluoroaniline (TCF) have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, ESR, thermal, magnetic susceptibility, electrical conductivity and XRD analysis. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal:ligand) ratio with the coordination 4 or 6. FAB-mass and thermal data show degradation pattern of the complexes. The thermal behavior of metal complexes shows that the hydrated complexes loses water molecules of hydration in the first step; followed by decomposition of ligand molecules in the subsequent steps. The crystal system, lattice parameter, unit cell volume and number of molecules in unit cell in the lattice of complexes have been determined by XRD analysis. XRD patterns indicate crystalline nature for the complexes. The solid state electrical conductivity of the metal complexes has also been measured. Solid state electrical conductivity studies reflect semiconducting nature of the complexes.
