13,757 research outputs found

    Effect of Co Doping on the Structure and Magnetic Properties of TmMn1-xCoxO3

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    We report the structure and magnetic properties of Co-doped TmMnO3 polycrystals for Co doping levels of 0 ≤ x ≤ 0.9. TmMnO3 (x = 0) prepared at ambient pressure was hexagonal. Hexagonal and orthorhombic phases coexisted in TmMn1−xCoxO3 for 0 ≤ x < 0.5. We obtained almost single-phase orthorhombic samples with 0.5 ≤ x ≤ 0.9 using complex polymerization. Ferromagnetic orthorhombic TmMn1−xCoxO3 formed upon Co doping. The ionic states of Tm, Mn, and Co were determined through magnetization measurements. The rapid decrease in magnetization for 0.5 ≤ x ≤ 0.7 below about 25 K was explained using a model consisting of a combination of ferromagnetic Mn–Co and paramagnetic Tm sublattices

    Investigation into the effect of Y, Yb doping in Ba2In2O5: determination of the solid solution range and co-doping with phosphate

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    In this paper we examine the effect of Y, Yb doping in Ba2In2O5, examining the solid solution range and effect on the conductivity and CO2 stability. The results showed that up to 35% Y, Yb can be introduced, and this doping leads to an introduction of disorder on the oxygen sublattice, and a corresponding increase in conductivity. Further increases in Y, Yb content could be achieved through co-doping with phosphate. While this co-doping strategy led to a reduction in the conductivity, it did have a beneficial effect on the CO2 stability, and further improvements in the CO2 stability could be achieved through La and P co-doping

    First principles calculation of lithium-phosphorus co-doped diamond

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    We calculate the density of states (DOS) and the Mulliken population of the diamond and the co-doped diamonds with different concentrations of lithium (Li) and phosphorus (P) by the method of the density functional theory, and analyze the bonding situations of the Li-P co-doped diamond thin films and the impacts of the Li-P co-doping on the diamond conductivities. The results show that the Li-P atoms can promote the split of the diamond energy band near the Fermi level, and improve the electron conductivities of the Li-P co-doped diamond thin films, or even make the Li-P co-doped diamond from semiconductor to conductor. The effect of Li-P co-doping concentration on the orbital charge distributions, bond lengths and bond populations is analyzed. The Li atom may promote the split of the energy band near the Fermi level as well as may favorably regulate the diamond lattice distortion and expansion caused by the P atom.Comment: 14 pages, 11 figure

    A brief review of co-doping

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    AbstractDopants and defects are important in semiconductor and magnetic devices. Strategies for controlling doping and defects have been the focus of semiconductor physics research during the past decades and remain critical even today. Co-doping is a promising strategy that can be used for effectively tuning the dopant populations, electronic properties, and magnetic properties. It can enhance the solubility of dopants and improve the stability of desired defects. During the past 20 years, significant experimental and theoretical efforts have been devoted to studying the characteristics of co-doping. In this article, we first review the historical development of co-doping. Then, we review a variety of research performed on co-doping, based on the compensating nature of co-dopants. Finally, we review the effects of contamination and surfactants that can explain the general mechanisms of co-doping.</jats:p
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