Analysis, characterization and some properties of polyacrylamide-Ni(II) complexes

The complexation of polyarylamide (PAam) with Ni(II) metal ions at different concentrations was investigated. The metal complexes were characterized by fourier transform infrared spectroscopy (FTIR), UV-visible, differential scanning calorimeter (DSC) and atomic force microscope (AFM). FTIR spectroscopy was used to study the characteristic shifts of the absorbance bands of C=O and N-H2. UV-visible spectroscopy was used to follow the complex formation of PAam-Ni(II) and showed the appearance of a new band that was absent both in PAam and Ni(II) salt solutions. Thermal parameters, such as the glass transition temperature (Tg) and the melting point (Tm) of the polymer-metal complex have been measured by DSC. The variation of Tg and Tm with different Ni(II) concentrations was attributed to the complexation of the native polymer during the increasing of Ni(II) concentration. AFM was used to study the surface morphology of PAam films and its complexation with Ni(II) at different concentrations. The root mean square roughness increased as the Ni(II) concentration increases

Promoting p -based Hall effects by p−d−f hybridization in Gd-based dichalcogenides

We conduct a first-principles study of Hall effects in rare-earth dichalcogenides, focusing on monolayers of the H-phase EuX$_2$ and GdX$_2$ , where X = S, Se, and Te. Our predictions reveal that all EuX$_2$ and GdX$_2$ systems exhibit high magnetic moments and wide band gaps. We observe that while in the case of EuX$_2$ the p and f states hybridize directly below the Fermi energy, the absence of f and d states of Gd at the Fermi energy results in the p-like spin-polarized electronic structure of GdX$_2$ , which mediates p-based magnetotransport. Notably, these systems display significant anomalous, spin, and orbital Hall conductivities. We find that in GdX$_2$ , the strength of correlations controls the relative position of the p, d, and f states and their hybridization, which has a crucial impact on p-state polarization and the anomalous Hall effect, but not the spin and orbital Hall effects. Moreover, we find that the application of strain can significantly modify the electronic structure of the monolayers, resulting in quantized charge, spin, and orbital transport in GdTe$_2$ via a strain-mediated orbital inversion mechanism taking place at the Fermi energy. Our findings suggest that rare-earth dichalcogenides hold promise as a platform for topological spintronics and orbitronics

Promoting pp-based Hall effects by pp-dd-ff hybridization in Gd-based dichalcogenides

We conduct a first-principles study of Hall effects in rare-earth dichalcogenides, focusing on monolayers of the H-phase EuX$_2$ and GdX$_2$, where X = S, Se, and Te. Our predictions reveal that all EuX$_2$ and GdX$_2$ systems exhibit high magnetic moments and wide bandgaps. We observe that while in case of EuX$_2$ the $p$ and $f$ states hybridize directly below the Fermi energy, the absence of $f$ and $d$ states of Gd at the Fermi energy results in $p$-like spin-polarized electronic structure of GdX$_2$, which mediates $p$-based magnetotransport. Notably, these systems display significant anomalous, spin, and orbital Hall conductivities. We find that in GdX$_2$ the strength of correlations controls the relative position of $p$, $d$ and $f$-states and their hybridization which has a crucial impact on $p$-state polarization and the anomalous Hall effect, but not the spin and orbital Hall effect. Moreover, we find that the application of strain can significantly modify the electronic structure of the monolayers, resulting in quantized charge, spin and orbital transport in GdTe$_2$ via a strain-mediated orbital inversion mechanism taking place at the Fermi energy. Our findings suggest that rare-earth dichalcogenides hold promise as a platform for topological spintronics and orbitronics.Comment: 12 pages, 5 figure

Functional Π-conjugated polymers based on maleimide for photovoltaic applications

A series of new bis-(2-thienyl) maleimide monomers have been synthesized and characterized. The bis-(2thienyl)maleimide unit has been copolymerized with dierent aromatic comonomers. Stille coupling polymerizations under various conditions have been utilized. The copolymers were then characterized by size-exclusion chromatography and their optical and electronic properties were investigated by UV-Vis absorption spectroscopy and cyclic voltammetry. All maleimide based copolymers shared similar LUMO energy levels, which are largely determined by the acceptor moiety, and are close to that of PC61BM to be eective for charge dissociation. These low band gap polymers have been tested for photovoltaic applications and have shown moderate photovoltaic performance. Interesting results were obtained by adding the polymer to the P3HT:PC61BM mixture, as a third component. The ternary blend BHJ solar cells showed power conversion eciencies of 35% exceeding those of the corresponding binary blends

Electric Field-Induced Fabrication Of Microscopic Si-Based Optoelectronic Devices For 1.55 And 1.16 Μm Ir Electroluminescence

We suggest an alternative technique for electroluminescent device fabrication, based on our earlier findings of electric field (E-field)-induced bipolar transistor creation in Si, doped with Li. An external electric field served to induce μm sized electroluminescent device structures in Si, that had been doped prior to E-field application, with Li, and Er via thermal in-diffusion. Such devices exhibit low temperature, near infrared (IR) electroluminescence at ∼ 1.16 and 1.55 μm, corresponding to transitions associated with Li and Er levels, respectively, in the forbidden gap. While Li also creates radiative recombination centers in Si, the Er-based IR radiation is the most desirable one. At the same time Li-doping is what makes E-field-induced p-n junction fabrication possible. © 2001 Elsevier Science B.V

Promoting p -based Hall effects by p − d − f hybridization in Gd-based dichalcogenides

We conduct a first-principles study of Hall effects in rare-earth dichalcogenides, focusing on monolayers of the H-phase EuX2 and GdX2 , where X = S, Se, and Te. Our predictions reveal that all EuX2 and GdX2 systems exhibit high magnetic moments and wide band gaps. We observe that while in the case of EuX2 the p and f states hybridize directly below the Fermi energy, the absence of f and d states of Gd at the Fermi energy results in the p-like spin-polarized electronic structure of GdX2 , which mediates p-based magnetotransport. Notably, these systems display significant anomalous, spin, and orbital Hall conductivities. We find that in GdX2 , the strength of correlations controls the relative position of the p, d, and f states and their hybridization, which has a crucial impact on p-state polarization and the anomalous Hall effect, but not the spin and orbital Hall effects. Moreover, we find that the application of strain can significantly modify the electronic structure of the monolayers, resulting in quantized charge, spin, and orbital transport in GdTe 2 via a strain-mediated orbital inversion mechanism taking place at the Fermi energy. Our findings suggest that rare-earth dichalcogenides hold promise as a platform for topological spintronics and orbitronics