Intrinsic anomalous spin Hall effect

Charge-spin interconversion in magnetic materials is investigated by using the first-principles calculations.In addition to the conventional spin Hall effect(SHE) that requires mutual orthogonality of the charge current,spin-flow direction,and spin polarization,the recently proposed anomalous SHE(ASHE) is confirmed in Mn2Au and WTe2.The interaction of the order parameter with conduction electrons leads to sizeable non-zero spin Berry curvatures that give rise to anomalous spin Hall conductivity(ASHC).Our calculations show that the ASHE is intrinsic and originates from the order-parameter-controlled spin-orbit interaction,which generates an extra anomalous effective field.A useful relationship among the order parameter,the spin Berry curvature,and the ASHC is revealed.Our findings provide a new avenue for generating and detecting arbitrary types of spin currents.

The fabrication of flower-like graphene/octadecylamine composites

Three-dimensional flower-like nanomaterials have wide application due to the large specific surface area.In this letter,the morphology of octadecylamine（ODA） from several common solvents is studied and it is found that from the chloroform and acetone solution,ODA assembles into petal-like structure,which further forms the spherical or flower-like architecture.Furthermore,the composite materials incorporated reduced graphene oxide（rGO） and ODA could well keep the flower-shaped structure of ODA.XRD results show that the introduction of graphene has little influence on the structure of ODA and contact angle test indicates good hydrophobic performance of the rGO/ODA material.

Gold nanoparticles/carbon nanotubes composite microspheres for catalytic reduction of 4-nitrophenol

The layer-by-layer assembly of polyethyleneimine and carbon nanotubes is carried out through the electrostatic interactions on colloidal polystyrene templates. The successful spherical growth of polyethyleneimine/carbon nanotube multilayers could be investigated by SEM. The subsequent in situ preparation and deposition of gold nanoparticles on the core–shell composites could yield novel microsphere complexes, which are characterized by SEM, TEM, EDX and XRD. The functional hierarchical microspheres with gold nanoparticles exhibit good catalytic activity in the reaction of reducing 4-nitrophenol to 4-aminophenol.

Intriguing magnetoelectric effect in two-dimensional ferromagnetic/perovskite oxide ferroelectric heterostructure

Two-dimensional (2D) magnets have broad application prospects in the spintronics,but how to effectively control them with a small electric field is still an issue.Here we propose that 2D magnets can be efficiently controlled in a multiferroic heterostructure composed of 2D magnetic material and perovskite oxide ferroelectric (POF) whose dielectric polarization is easily flipped under a small electric field.We illustrate the feasibility of such strategy in the bilayer CrI_(3)/BiFeO_(3)(001) heterostructure by using the first-principles calculations.Different from the traditional POF multiferroic heterostructures which have strong interface interactions,we find that the interface interaction between CrI_(3) and BiFeO_(3)(001) is van der Waals type.Whereas,the heterostructure has particular strong magnetoelectric coupling where the bilayer CrI_(3) can be efficiently switched between ferromagnetic and antiferromagnetic types by the polarized states P↑ and P↓ of BiFeO_(3)(001).We also discover the competing effect between electron doping and the additional electric field on the interlayer exchange coupling interaction of CrI_(3),which is responsible to the magnetic phase transition.Our results provide a avenue for the tuning of 2D magnets with a small electric field.

Strengthened graphene oxide/diazoresin multilayer composites from layer-by-layer assembly and cross-linking

The layer-by-layer assembly of graphene oxide and diazoresin is carried out via the electrostatic and hydrogen bond interactions on planar substrates and colloidal templates.The successful planar and spherical growth of multilayer could be investigated by UV-vis spectrophotometry and scanning electron microscopy,respectively.Subsequent UV irradiation or heating would convert the ionic bonds and hydrogen bonds to covalent bands,which significantly improves the stability of the multilayer composite against solvent etching.For the cross-linked core-shell composites,the template cores could be removed by dissolution and hollow microspheres are obtained.