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The strength and direction of the exchange bias in a spin valve is changed and recovered by applying a spin-polarized current pulse. The model for spin-momentum transfer has shown that the experiments can be rationalized in terms of changing micromagnetic distributions at the ferromagnetic/antiferromagnetic interface.

Spin-polarized current-changed exchange bias is seen in NiFe/Cu/NiFe/FeMn spin valve with a current-in-plane geometry The results have shown that a spin-polarized current has exerted a torque at antiferromagnetic metals due to interactions between polarized electrons and the antiferromagnetic moments.

We design and experimentally demonstrate a broadband metamaterial absorber in the terahertz (THz) band based on a periodic array of aluminum (Al) squares with two different sizes. A thin silicon dioxide (SiO2) film rather than a conventional polyimide (PI) layer is used as a dielectric spacer to separate Al squares from the platinum (Pt) ground plane in our design, which significantly improves the design precision and the feasibility of the device fabrication. The combination of different sizes of Al squares gives rise to an absorption bandwidth of over 210 GHz with an absorption of over 90%. Our results also show that our device is almost polarization-insensitive. It works very well for all azimuthal angles with an absorption of beyond 80%. [ABSTRACT FROM AUTHOR]

The effects of BaCu(B2O5) (BCB) addition on the microstructure, phase formation, and microwave dielectric properties of Ba5Nb4O15−BaWO4 ceramic are investigated. As a sintering aid, BaCu(B2O5) ceramic could effectively lower the sintering temperature of Ba5Nb4O15−BaWO4 ceramic from 1100 °C to 950 °C due to the liquid-phase effect. Meanwhile, BaCu(B2O5) addition effectively improves the densification of Ba5Nb4O15−BaWO4 ceramic and significantly influences the microwave dielectric properties. X-ray diffraction analysis reveals that Ba5Nb4O15 and BaWO4 coexist with no crystal phase of BaCu(B2O5) in the sintered ceramics. The Ba5Nb4O15−BaWO4 ceramics with 1.0 wt% BaCu(B2O5) sintered at 950 °C for 2 h presents good microwave dielectric properties of εr = 19.0, high Q×f of 33802 GHz and low τf of 2.5 ppm/°C. [ABSTRACT FROM AUTHOR]

The effects of the addition of H3BO3 on the microstructure, phase formation, and microwave dielectric properties of (Zn0.7Mg0.3)TiO3 ceramics sintered at temperatures ranging from 890 °C to 950 °C are investigated. H3BO3 as a sintering agent can effectively lower the sintering temperature of ZMT ceramics below 950 °C due to the liquid-phase effect. The microwave dielectric properties are found to strongly correlate with the amount of H3BO3. With the increase in H3BO3 content, the dielectric constant (εr) monotonically increases, but the quality factor (Q × f) reaches a maximum at 1 wt% H3BO3, and the apparent density of ZMT ceramics with H3BO3 ≥ 1 wt% gradually decreases. At 950 °C, the ZMT ceramics with 1% H3BO3 exhibit excellent microwave dielectric properties: εr = 19.8, and Q × f = 43800 GHz (8.94 GHz). [ABSTRACT FROM AUTHOR]

Polycrystalline Fe3O4 films grown on different thicknesses of Fe underlayers were prepared by dc reactive-magnetron sputtering in an Ar+O2 gas mixture and annealing under an infrared-lamp furnace system. Analyses of structural and magnetic properties revealed that a 15 nm Fe underlayer can be oxidized to Fe3O4 by increasing the oxygen flow rates during initial Fe3O4 layer growth. These analyses also confirmed the stoichiometry and high-crystallographic quality of grown Fe3O4. Adopting this method, Fe3O4 films can be grown without any other elemental buffer layers. [ABSTRACT FROM AUTHOR]

High quality VO2 thin films have been fabricated on silicon substrates using magnetron sputtering by introducing Al2O3 thin films as a buffer. The ultrathin Al2O3 deposited by plasma-assisted atomic layer deposition leads to a greatly improved crystallinity and textures in VO2 films. Dramatic change in electrical resistivity (4 orders of magnitude) and a small thermal hysteresis loop (~4 K) are obtained across the metal–insulator phase transition (MIT). Remarkably, by applying perpendicular voltage to a VO2/Al2O3 based metal/VO2/semiconductor device, electrically driven MIT switching characteristics have been observed with a tiny tunneling leakage current of ~10 μA. These results show that an electric field alone is sufficient to trigger the MIT, and the realization of VO2 based ultrafast electrical switching devices on a silicon substrate is possible. [ABSTRACT FROM AUTHOR]

Objective: To investigate the changes of platelet count (PLT), plateletcrit (PCT), mean platelet volume (MPV) and platelet distribution width (PDW) before and after apheresis platelet transfusion, the correlation between the parameters and their clinical significance., Methods: A total of 38 patients who received apheresis platelet transfusion were selected, their results of blood routine test closest to the time point of apheresis platelet transfusion were consulted from hospital information system and the changes of PLT, PCT, MPV and PDW were compared before and after transfusion. The correlation between above parameters was analyzed. The correlation of body mass index (BMI) with the increased multiple and increased value after platelet infusion was also analyzed., Results: Compared with pre-infusion, PLT and PCT significantly increased (both P <0.001) while MPV and PDW showed no significant difference after apheresis platelet transfusion ( P >0.05). The difference of PLT and PCT before and after apheresis platelet transfusion had no correlation with PLT and PCT before transfusion ( r =0.002, r =0.001), while the difference of MPV and PDW was negatively correlated with MPV and PDW before transfusion ( r =-0.462, r =-0.610). The PLT growth rate was positively correlated with PCT growth rate before and after apheresis platelet transfusion ( r =0.819). BMI was positively correlated with the increased multiple of PLT after infusion ( r =0.721), but not with the increased value of PLT after infusion ( r =0.374)., Conclusion: Apheresis platelet transfusion can cause platelet parameters change and shows different characteristics. Characteristic changes of platelet parameters and their correlation can be used as reference indices to evaluate the efficacy of apheresis platelet transfusion.