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Two ferromagnetic transitions have been found by temperature dependence ac susceptibility experiments on as-prepared bulk polycrystalline La0.9Ba0.1MnO3. Investigation indicates that the higher temperature transition (TCh) can be attributed to the oxygen excessive phase La0.9Ba0.1MnO3+δ at the surface, while the lower temperature transition (TCl) can be attributed to the interior stoichiometric phase La0.9Ba0.1MnO3 of the samples. Softening of ferromagnetic system near TCl has been observed in La0.9Ba0.1MnO3, which can be explained by the freezing of misorder of metal ion at higher temperature. [ABSTRACT FROM AUTHOR]

The Au/Nb-1.0 wt %-doped SrTiO3 junctions were successfully fabricated by magnetic controlled sputtering and annealing process. Backward diodelike behaviors were observed in as-prepared junction and the one annealed at 350 °C. Transition to Schottky behavior was found in the junction annealed at 750 °C; the Schottky junction shows linear capacitance-voltage (C-2-V) relationship in the reverse condition with barrier heights determined to be 1.6 eV. The results of current-voltage (I-V) measurements reveal that high temperature annealing can alter interface barrier and thereby ameliorate the stability of leakage current remarkably. [ABSTRACT FROM AUTHOR]

Short-range order in amorphous intergranular films in SiC hot pressed with Al, B, and C additives was recognized with autocorrelation processing of high-resolution electron microscopy images. The short-range order corresponds to Al–O–C tetrahedra formed near the SiC matrix grains. In situ heating high-resolution transmission electron microscopy study demonstrated that the amorphous-to-crystalline transformation in the amorphous Al–O–C intergranular films started from nucleation and local growth of the short-range order structure. [ABSTRACT FROM AUTHOR]

Cesium lead halide perovskites have shown great potential applications in photoelectric devices because of their high quantum efficiency, good stability, and tunable bandgap. Herein, we prepared CsPbBr3 microwires with a high crystal quality, smooth surface, and rectangular cross section via the solution method. The as-prepared microwires presented a high quality whispering gallery mode lasing with a low threshold of 9.1 μJ cm−2 and a high quality factor of ∼3000. Furthermore, we obtained the alloys of CsPbClxBr3−x (0 < x < 2) microwires through the gas-phase anion exchange method and realized the wavelength tunable single-mode lasing emission ranging from ∼546.8 nm to ∼468.0 nm. This work will expand the practical application of lead halide perovskites in spectrograph, optical communication, and in-chip photoelectric devices. [ABSTRACT FROM AUTHOR]

We theoretically investigate the spin-orbit interaction effects on the Andreev reflection and the spin accumulation in a quantum dot embedded in an Aharonov-Bohm interferometer. Due to the spin-dependent phase caused by the spin-orbit (SO) interaction, the electron occupation number becomes spin dependent and the spin accumulation can appear in the quantum dot (QD). Furthermore, in the presence of a magnetic flux, the spin accumulation of the dot can even be reversed by tuning the gate voltage. The magnitude and direction of the spin accumulation in the QD can be easily controlled by the gate voltage, magnetic flux, and the SO interaction. The Andreev reflection current also exhibits a spin polarization under the influence of both the spin-orbit interaction and the magnetic field through the ring. The spin polarization of the current can be tuned by varying the spin-orbit interaction strength and the magnetic flux. This provides an efficient mechanism to control the spin accumulation and the Andreev reflection in the quantum dot. [ABSTRACT FROM AUTHOR]

Provides information on a study that focused on the effective interband g factors at the Γ and L points of the Brillouin zone, where the Faraday spectra were measured and then fitted by the multioscillator model.

To improve the stability of organic multifunctional materials and enhance the ON/OFF ratio, a donor-π-acceptor molecule with the triphenylamine (TPA) unit is designed and synthesized. The TPA unit can effectively stabilize the charge transferred state, and the thin film shows excellent bistable electronic switching behavior with high ON/OFF current ratio of about 105. Meanwhile, reversible and stable nanometer-scale data storage is realized on the thin film by applying pulsed voltages, and optical information storage is achieved simultaneously by utilizing fluorescence changes under UV irradiation. [ABSTRACT FROM AUTHOR]

ZnO nanowires were obtained through evaporation of zinc powders under a low temperature of 400 °C. These ZnO nanowires, in the diameter of ∼10 nm, were long and curved with lengths of tens of micrometers. High-resolution transmission electron microscopy showed these ZnO nanowires were mostly crystalline structure; however, the kink parts contained dislocations and stacking faults. Furthermore, the movement of dislocations was observed in the kink parts under e-beam irradiation. Photoluminescence and Raman spectra show that there exist oxygen vacancies in the ZnO nanowires. Possible reasons for the growth and properties of ZnO nanowires were discussed. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

TbMnO3 thin films with different crystallographic orientations were deposited epitaxially on LaAlO3 [100] and SrTiO3 [100] single crystal substrates by using pulsed laser deposition. Magnetization measurements were performed along the [110], [-110], and [001] directions of the films. Obvious magnetic anisotropy and low temperature ferromagnetism were found. Transitions at T ∼ 10, 32, 120, and 125 K along different directions are observed. The susceptibility anomalies, remarkably anisotropic, are discussed on the frame of the domain wall and strain-induced distortion. Particularly, the lattice mismatch and the anisotropic thermal expansion between the films and substrates are likely responsible for the distortion behaviors. [ABSTRACT FROM AUTHOR]