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Electrolyte gating technology has been widely used as an effective tool to study novel physics at complex oxide surfaces and interfaces. Certain emergent phenomena reported in electro-gated SrTiO3 (STO) surfaces are particularly interesting. Here, we report on the disparate electron transport behaviors of electrolyte-gated STO (001) and (110) oriented surfaces. In contrast to the anomalous transport from an insulating state to a Kondo-like state and then metallic states on the (001) surface, with increasing carrier density, the (110) surface always behaves as an insulating state. A comparison study suggests that the oxygen vacancies and localized Ti3+ ions on the (001) surface are scatter carriers, but no such defects are found on the (110) surface. This suggests that these surfaces are intrinsically insulating, and the observed anomalous effects are likely induced by the Ti3+ ions and oxygen vacancies introduced during electrolyte gating. This work sheds light on complicated phenomena in electrolyte-gated STO-based systems. [ABSTRACT FROM AUTHOR]

Antiferromagnetic spintronics has been receiving attention recently, while spin-texture dependent magnetoresistance (MR) represents one of the main mechanisms for magnetic data storage. In particular, sufficiently large MR with high operating temperatures would be highly required for advanced spintronic applications. In this work, we experimentally investigate the MR effect of well-known antiferromagnet α-Fe2O3 (hematite) in a single crystal form, which has the Morin transition temperature as high as Tm ∼ 260 K. It is revealed that the MR effect associated with the spin-texture re-alignment, i.e., the spin-flop from the out-of-plane direction (c axis) to the in-plane direction, driven by sufficiently low magnetic fields inclined along the [012] direction, reaches up to ∼2.5% at temperature T ∼ 250 K. The first-principles calculations suggest that this MR effect originates from the reduced bandgap due to the spin-flop and the finite spin–orbital coupling. The present work sheds light on the possibility of α-Fe2O3 as a favored MR-based candidate for near-room temperature spintronics. [ABSTRACT FROM AUTHOR]

The rare-earth double-perovskite R2CoMnO6 family has been reported to be promising multiferroics where the predicted ferroelectric polarization along the b-axis is induced by the Co2+/Mn4+ collinear magnetic order. In this work, we report our characterizations on the structural, magnetic, dielectric, and ferroelectric behaviors of flux-grown Y2CoMnO6 single crystals. A weak ferromagnetic transition with the Curie point TC ∼ 70 K is evident in combination with a remarkable magnetic hysteresis loop along the c-axis. The earlier reported dielectric anomaly at the magnetic transition is not detected in our single crystals. In addition, the peak of each electric current curve as a function of temperature, probed along different crystallographic directions, shows serious shifting with the temperature ramping rate, excluding the intrinsic ferroelectric contribution. The measured data are not in conformity with theoretical predictions and earlier experiments on polycrystalline samples. In addition, no reliable sign for magnetoelectric coupling can be detected. The present work seems to exclude the existence of magnetism-driven ferroelectricity in Y2CoMnO6. [ABSTRACT FROM AUTHOR]

Integrating deep learning with traditional machine learning methods is an intriguing research direction. For example, PCANet and LDANet adopts Principal Component Analysis (PCA) and Fisher Linear Discriminant Analysis (LDA) to learn convolutional kernels separately. It is not reasonable to adopt LDA to learn filter kernels in each convolutional layer, local features of images from different classes may be similar, such as background areas. Therefore, it is meaningful to adopt LDA to learn filter kernels only when all the patches carry information from the whole image. However, to our knowledge, there are no existing works that study how to combine PCA and LDA to learn convolutional kernels to achieve the best performance. In this paper, we propose the convolutional coverage theory. Furthermore, we propose the PLDANet model which adopts PCA and LDA reasonably in different convolutional layers based on the coverage theory. The experimental study has shown the effectiveness of the proposed PLDANet model. [ABSTRACT FROM AUTHOR]

The polar magnet, Fe2Mo3O8 (FMO), with linear magnetoelectric (ME) coupling, is a promising candidate for multiferroic applications in advanced spin devices. However, a giant magnetic bias (Hb) is needed for optimizing the inverse ME effect, i.e., electric field (E) modulation of magnetization (M), which is still a core issue. Herein, we utilize the chemical doping route to enhance the sensitivity of controlling the competitive magnetic interactions and/or multiferroic phases by means of introducing nonmagnetic Zn2+ ions into FMO crystals. Compared with FMO, the Zn-doped composition (Fe0.95Zn0.05)2Mo3O8 (FZMO) generates three metastable magnetic states in the middle of antiferromagnetic and ferrimagnetic states, along with obvious ferroelectric polarization. The inverse ME effect of FZMO is intact with a relative change of ΔM ≈ 0.06 μB/f.u. responding to an E value of ± 20 kV/cm at 52 K. Most interestingly, the exciting Hb is dramatically dropped to 0.8 T for FZMO from 5.1 T for FMO, which is in favor of the application of ME coupling. It is suggested that the perturbation of magnetic interactions via substituting specific sites by nonmagnetic ions plays a key role in decreasing the exciting Hb without deteriorating the inverse ME coupling in this polar M2Mo3O8 family. [ABSTRACT FROM AUTHOR]

Abstract. -- OBJECTIVE: To elucidate the role of microRNA-34c-5p (miRNA-34c-5p) in the pro-gression of hepatocellular carcinoma (HCC) and the indicated mechanism. PATIENTS AND METHODS: Relative levels of miRNA-34c-5p and FAM83A in HCC tissues and cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Their in- fluences on clinical features in HCC patients were analyzed. Kaplan-Meier method was introduced for assessing the relationship between miRNA- 34c-5p and overall survival in HCC. After overexpression of miRNA-34c-5p in HepG2 and HB611 cells, we detected proliferative, migratory and invasive abilities by cell counting kit-8 (CCK-8) and transwell assay. The interaction between miRNA- 34c-5p and FAM83A was explored by Dual-Luciferase reporter assay. Finally, their co-regulation on HCC cell phenotypes was examined. RESULTS: MiRNA-34c-5p was downregulated in HCC tissues, especially stage III+IV cases. Its level was correlated to tumor size, tumor number and TNM staging in HCC. Overexpression of miRNA-34c-5p inhibited proliferative, migratory and invasive abilities in HepG2 and HB611 cells. In addition, miRNA-34c-5p targeted on FAM83A and negatively regulated its level. Overexpression of FAM83A could reverse the inhibitory effects of miRNA-34c-5p on malignant pheno-types of HCC cells. CONCLUSIONS: By negatively regulating FAM83A level, miRNA-34c-5p alleviates the progression of HCC. [ABSTRACT FROM AUTHOR]

The training effect has been systematically studied in exchange coupled NiFe2O4/NiO nanogranular system. Both exchange bias field (HEB) and vertical magnetization shifts (MShift) can be observed after the system field cooled from 350 K to low temperatures, which decrease monotonically through consecutive loop cycles. During this procedure, linear dependence between HEB and MShift is found for this system, revealing the critical role of the pinned uncompensated spins. With the increase of cooling field, the relative change of HEB becomes more pronounced, which shows that the rapid reduction of the pinned uncompensated spins for high cooling field. Moreover, the reduction of HEB becomes weakened with decreasing measured temperatures, which indicated the spin configuration at low temperatures possesses higher dynamic stability. The cooling field and temperature dependence on training effect is discussed in terms of the evolution of the metastable spin configurations at the interfaces and fitted by a recent theoretical model. [ABSTRACT FROM AUTHOR]

Using the first-principle calculations, we investigate in detail the structure instability resulting from softening of the polar zone-center phonon mode [ferroelectric (FE) instability] and nonpolar zone-boundary mode [antiferrodistortive (AFD) instability] in cubic BaZrO3 (BZO) under hydrostatic pressure P from -20 to 90 GPa. The hydrostatic pressure enhances the AFD instability, while it suppresses and then enhances the FE instability. A sequence of FE→cubic→AFD→AFD/FE phase transitions with increasing P is predicted. A careful examination of the pressure dependence of full phonon dispersions and interatomic force constants in real space reveals the microscopic key interactions in driving the transitions. With increasing pressure P, the drastically evolving short-range forces suppress the FE instability induced by the long-range dipole-dipole forces under low pressure, and enhance both the AFD and FE instability under high pressure. We investigate the dielectric properties of cubic BZO under hydrostatic pressure. The dielectric constant as a function of pressure shows a minimum contributed from the TO1 mode with the lowest frequency. We argue that this pressure dependence of the dielectric constant mainly originates from fluctuations of the SR forces. [ABSTRACT FROM AUTHOR]

The dielectric relaxation and magnetocapacitance effect of one-dimensional spin frustrated compound Ca3Co2O6 are investigated. The steplike magnetocapacitance effect is observed and one to one corresponds to the steplike magnetization. We explain this phenomenon from the spin configuration dependent dielectric response. The simulation results using the Monte Carlo method are in good agreement with experimental data at low temperature. The close correspondence between the magnetic and dielectric properties indicates that the coupling is the intrinsic character of Ca3Co2O. The steplike magnetocapacitance effect may find potential applications in data storage and sensors. [ABSTRACT FROM AUTHOR]

The conduction relaxations of polycrystalline La0.5Ca0.5Mn0.95Fe0.05O3 upon imposing rectangle electric current pulses (with minute time scale) are studied in details. We observe clear “overshooting” features of the conduction relaxation at both the front and rear edges of the current pulse so long as the pulse is sufficiently high. The Joule heating effect and the intrinsic stabilization of the ferromagnetic metal phase by the current pulse are linked in understanding our observations, and these effects may be applicable for resistance switching function. [ABSTRACT FROM AUTHOR]