Y. Jiang

Ballistic electron transport in hybrid ferromagnet/two-dimensional electron gas sandwich nanostructure: Spin polarization and magnetoresistance effect

We have theoretically investigated ballistic electron transport through a combination of magnetic-electric barrier based on a vertical ferromagnet/two-dimensional electron gas/ferromagnet sandwich structure, which can be experimentally realized by depositing asymmetric metallic magnetic stripes both on top and bottom of modulation-doped semiconductor heterostructures. Our numerical results have confirmed the existence of finite spin polarization even though only antisymmetric stray field B-z is considered. By switching the relative magnetization of ferromagnetic layers, the device in discussion shows evident magnetoconductance. In particular, both spin polarization and magnetoconductance can be efficiently enhanced by proper electrostatic barrier up to the optimal value relying on the specific magnetic-electric modulation

Ultra-thin BiFeO 3 nanowires prepared by a sol-gel combustion method: An investigation of its multiferroic and optical properties

Perovskite-type polycrystalline BiFeO3 nanowires, with 150xa0nm in length and 10xa0nm in diameter, were synthesized using a sol–gel combustion method at a relative low reactive temperature. The BiFeO3 nanowires exhibit a remarkably high saturation magnetization of 4.22 emu/g finite coercivity (177 Oe), and a enhanced Mr/Ms value about 0.22, which is independent on the synthesize temperature. The permittivity constant (ε′) and dielectric loss (0.01 at 0.4xa0MHz) of BiFeO3 nanowires are very low as compared to reported BiFeO3 bulk and film. In addition, BiFeO3 nanowires reveal a wide band gap of 2.5xa0eV measured from the UV–visible diffuse reflectance spectrum, which may be useful as a photoelectrode material and photocatalytic decomposition of contamination.

Anomalous Hall effect and spin-orbit torques in MnGa/IrMn films: Modification from strong spin Hall effect of the antiferromagnet

We report systematic measurements of anomalous Hall effect (AHE) and spin-orbit torques (SOTs) in MnGa/IrMn films, in which a single

In-plane stray field induced spin-filtering in a two-dimensional electron gas under the modulation of surface ferromagnetic dual-gate

L{1}_{0}text{ensuremath{-}}mathrm{MnGa}

Enhanced ferroelectric and UV photocatalytic properties in a Bi4Ti3O12@ZnO core–shelled nanostructure

epitaxial layer reveals obvious orbital two-channel Kondo (2CK) effect. As increasing the thickness of the antiferromagnet IrMn, the strong spin Hall effect (SHE) has gradually suppressed the orbital 2CK effect and modified the AHE of MnGa. A scaling involving multiple competing scattering mechanisms has been used to distinguish different contributions to the modified AHE. Finally, the sizeable SOT in the MnGa/IrMn films induced by the strong SHE of IrMn have been investigated. The IrMn layer also supplies an in-plane exchange bias field and enables nearly field-free magnetization reversal.

Improved electrical and ferroelectric properties of multiferroic Na0.5Bi0.5TiO3/Bi1.07Nd0.03FeO3/Na0.5Bi0.5TiO3 sandwiched structure by a sol–gel process

Based upon a hybrid ferromagnet/semiconductor structure consisting of two-dimensional electron gas and a pair of surface ferromagnetic stripes on top, we have theoretically investigated the effect of in-plane stray field omitted frequently in previous studies on the spin-dependent ballistic transport properties in hybrid structure. It is demonstrated here that, in combination with an external-controllable electrostatic modulation, the concerned structure shows a similar function as a lateral spin-polarized resonant tunneling device, where the strong spin-filtering effect occurs and nearly single-mode polarization is anticipated for the proper modulation. More importantly, the spin polarity of transmission electron can be easily transferred from one extreme to the other by switching the magnetization of stripes, showing the promising application as an efficient spin aligner in the developing semiconductor spintronics.

Polarization modulation resistive switching in a lead-free ferroelectric Pt/Bi 0.5 Na 0.5 TiO 3 /La 0.67 Sr 0.33 MnO 3 sandwiched heterostructure

Composited Bi4Ti3O12@ZnO nanoparticles with a core of Bi4Ti3O12 (BIT) and a shell of ZnO have been synthesized by liquid chemical reaction method. Compared with pure BIT nanoparticles, the ferroelectricity in BIT@ZnO core–shell nanostructure was greatly enhanced. Moreover, the dielectric loss of BIT@ZnO is lower than that of BIT nanoparticles in a low frequency range. The band gap energy of BIT@ZnO core@shell nanostructure is larger than that of BIT, which formed as a type-II band alignment. Furthermore, the BIT@ZnO core–shell nanoparticles exhibit better UV photodegradation activity for organic contaminant. Such a BIT@ZnO core@shell nanostructure may have potential applications in microelectronics, photoelectronic, and photocatalytic of contamination.

Enhanced spin-orbit torques in MnAl/Ta films with improving chemical ordering

A ferroelectric/multiferroic/ferroelectric sandwiched structure composed by Na0.5Bi0.5TiO3 (NBT) and Bi1.07Nd0.03FeO3 (BNF) with a LaNiO3 buffer layer were prepared by a sol–gel method. X-ray diffraction indicated the NBT/BNF/NBT films exhibited a pure perovskite structure. The average grain size of BNF and NBT/BNF/NBT were found to be 40 and 80xa0nm, respectively. Interestingly, the electrical and ferroelectric properties such as leakage current, dielectric constant, and remnant polarization of NBT/BNF/NBT sandwiched layer, were superior to those of BNF single film. However, the saturation magnetization of NBT/BNF/NBT sandwiched layer was reduced. Our work suggested the NBT/BNF/NBT sandwiched layer with improved multiferroic characteristics have a promising application for future information storage devices.

Room Temperature Ferromagnetism in Lithium-Doped ZnO

High-quality lead-free Bi0.5Na0.5TiO3 (BNT)/La0.67Sr0.33MnO3 (LSMO) bilayer was grown on SrTiO3 crystal by pulsed laser deposition method. Ferroelectric and electrical properties of the Pt/BNT/LSMO heterostructure have been investigated. Interestingly, an asymmetric current–voltage hysteresis exhibits a ferroelectric BNT modulated resistive switching characteristics in BNT/LSMO heterostructure without a forming process. The On/Off ratio of resistance switching behaviors is higher than 103 and retention time is longer than 105xa0s. The relationship between potential barriers and polarization charges at the Pt/BNT and BNI/LSMO interfaces has been discussed. The Pt/BNT/LSMO cell with both high On/Off ratio and long retention properties exhibits potentials in lead-free nonvolatile memory applications.

Butterfly-shaped multiferroic BiFeO3@BaTiO3 core-shell nanotubes: the interesting structural, multiferroic, and optical properties

We report the enhancement of spin-orbit torques (SOT) in MnAl/Ta films with improving chemical ordering through annealing. The switching current density is increased due to enhanced saturation magnetization MS and effective anisotropy field HK after annealing. Using harmonic measurements, we have found that both dampling-like effective field HD and field-like effective field HF were increased in the temperature range of 50 to 300u2009K, and the annealing has also enhanced the value of the spin Hall angle. The improved chemical ordering is considered to have enhanced the interfacial spin transparency and the transmitting of the spin current in the MnAl layer. The results suggest that MnAl films with high bulk perpendicular magnetic anisotropy are ideal for a systematic examination of SOT, in which the related magnetic and transport behaviors can be controllably varied with thermally tuned chemical ordering.