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Inhibition of autophagy has been widely viewed as a promising strategy for anticancer therapy. However, few effective and specific autophagy inhibitors have been reported. Herein, we described the design, synthesis, and biological characteristics of new analogues of strigolactones (SLs), an emerging class of plant hormones, against colorectal cancers. Among them, an enantiopure analogue

Single-phase multiferroic materials that allow the coexistence of ferroelectric and magnetic ordering above room temperature are highly desirable, motivating an ongoing search for mechanisms for unconventional ferroelectricity in magnetic oxides. Here, we report an antisite defect mechanism for room temperature ferroelectricity in epitaxial thin films of yttrium orthoferrite, YFeO3, a perovskite-structured canted antiferromagnet. A combination of piezoresponse force microscopy, atomically resolved elemental mapping with aberration corrected scanning transmission electron microscopy and density functional theory calculations reveals that the presence of YFe antisite defects facilitates a non-centrosymmetric distortion promoting ferroelectricity. This mechanism is predicted to work analogously for other rare earth orthoferrites, with a dependence of the polarization on the radius of the rare earth cation. Our work uncovers the distinctive role of antisite defects in providing a mechanism for ferroelectricity in a range of magnetic orthoferrites and further augments the functionality of this family of complex oxides for multiferroic applications., Ferroelectricity in orthoferrite perovskites has stimulated intense research, but the mechanism remains unclear. Here, the authors propose an antisite defect mechanism for introducing ferroelectricity in magnetically ordered YFeO3 and the family of rare earth orthoferrites.

The methods available to predict the strain and tension of geogrid are regularly based on two-dimensional condition, however, the three-dimensional deformed shape of geogrid is seldom considered in...

Searching for new materials and phenomena to enable voltage control of magnetism and magnetic properties holds compelling interest for the development of low-power nonvolatile memory devices. In particular, reversible and nonvolatile ON/OFF controls of magnetism above room temperature are highly desirable yet still elusive. Here, we report on a nonvolatile voltage control of magnetism in epitaxial SrCo1-xFexO3-δ (SCFO). The substitution of Co with Fe significantly changes the magnetic properties of SCFO. In particular, for the Co/Fe ratio of ∼1:1, a switch between nonmagnetic (OFF) and ferromagnetic (ON) states with a Curie temperature above room temperature is accomplished by ionic liquid gating at ambient conditions with voltages as low as ±2 V, even for films with thickness up to 150 nm. Tuning the oxygen stoichiometry via the polarity and duration of gating enables reversible and continuous control of the magnetization between 0 and 100 emu/cm3 (0.61 μB/f.u.) at room temperature. In addition, SCFO was successfully incorporated into self-assembled two-phase vertically aligned nanocomposites, in which the reversible voltage control of magnetism above room temperature is also attained. The notable structural response of SCFO to ionic liquid gating allows large strain couplings between the two oxides in these nanocomposites, with potential for voltage-controlled and strain-mediated functionality based on couplings between structure, composition, and physical properties.

Y-rich yttrium iron garnet (Y-YIG) thin films were grown on gadolinium gallium garnet substrates using pulsed laser deposition from a ${\mathrm{YFeO}}_{3}$ target. The films are epitaxial on the substrate, and the unit cell of (001)- and (111)-oriented Y-YIG undergoes a tetragonal or rhombohedral distortion, respectively. The Y-YIG has lower room temperature magnetization but higher low-temperature magnetization than bulk YIG, and its Curie temperature was in the range of 330--400 K, depending on the growth conditions. First-principles calculations predict that ${\mathrm{Y}}_{\mathrm{Fe}}$ antisite defects are more stable in octahedral than tetrahedral Fe sites. Temperature-dependent magnetization measurements together with a superexchange dilution model and composition determined from x-ray photoelectron spectroscopy indicate that nonmagnetic species (${\mathrm{Y}}^{3+}$ and vacancies) are predominantly accommodated in the octahedral sites, but there is a significant occupancy of tetrahedral sites.

A highly efficient and modular synthesis of nematode pheromone ascarosides was developed, which highlights a 4-step scalable synthesis of the common intermediate 10 in 23% yield from commercially available l-rhamnose by using orthoesterification/benzylation/orthoester rearrangement as the key step. Six diverse ascarosides were synthesized accordingly. Notably, biological investigations revealed that ascr#1 and ascr#18 treatment resulted in enhanced callose accumulation in Arabidopsis leaves. And ascr#18 also increased the expression of defense-related genes such as PR1, PDF1.2, LOX2 and AOS, which might contribute to the enhanced plant defense responses. This study not only allows a facile access to 1-O, 2-O, and 4-O substituted ascarosides, but also provides valuable insights into their biological activities in inducing plant defense response, as well as their mode of action.

Searching for new materials and phenomena to enable voltage control of magnetism and magnetic properties holds compelling interest for the development of low-power nonvolatile memory devices. In particular, reversible and nonvolatile ON/OFF controls of magnetism above room temperature are highly desirable yet still elusive. Here, we report on a nonvolatile voltage control of magnetism in epitaxial SrCo

This review describes recent progress in the growth and properties of self-assembled multiferroic perovskite–spinel nanocomposite thin films, in particular, BiFeO3–CoFe2O4, and their integration on silicon or pre-patterned substrates. Vertically aligned nanocomposite thin films, in which ferromagnetic spinel CoFe2O4 nanopillars grow in a ferroelectric perovskite BiFeO3 matrix, have been investigated for applications such as next generation memory devices. The strain transfer between the two oxide phases at the vertical interface enables cross-coupling of the properties, i.e. a magnetic (electric) field can modify the polarization (magnetization) state, making the nanocomposite a two-phase magnetoelectric multiferroic. The ability to grow high quality thin film nanocomposites and the control of their properties through epitaxial strain transfer are prerequisites for their incorporation into practical devices. Most work has been carried out on perovskite substrates using pulsed laser deposition, and integration on semiconductor-compatible substrates using scalable deposition processes presents a challenge. This review focuses on the epitaxial integration of BiFeO3–CoFe2O4 nanocomposite thin films using sputter deposition on silicon substrates, and discusses recent work on the formation of highly ordered nanocomposites using various template patterning methods. This robust, scalable route for large-area fabrication of multifunctional oxide nanocomposites using sputtering brings the exciting prospects offered by these materials closer towards technological realization.

BiFeO3, a room-temperature multiferroic material, has recently been increasingly applied as a potential lead-free piezoelectric material due to its large piezoelectricity achieved by doping. In this work, 12% Sm-doped BiFeO3 epitaxial thin films were fabricated on Nb-doped SrTiO3 (001) single crystal substrates via sol-gel method. The epitaxy was verified by reciprocal space mapping (RSM) and transmission electron microscope (TEM). The TEM results indicated the coexistence of R3c and Pbam phases in the film. The domains and piezoelectric properties from room temperature to 200 °C were characterized by piezoresponse force microscopy (PFM). Domains became active from 110 °C to 170 °C, and domain configurations changed obviously. A partially fading piezoresponse indicated the emergence of antiferroelectric Pbam. The in-situ domain analysis suggested that the phase transition was accompanied by domain wall motion. Switching spectroscopy PFM (SS-PFM) was further conducted to investigate the piezoresponse during the phase transition. Anomalous responses were found in both ON and OFF states at 170 °C, and the film exhibits typical antiferroelectric behavior at 200 °C, implying that the completion of phase transition and structure turned to the Pbam phase. This work revealed the origin of the high piezoresponse of Sm-doped BiFeO3 thin films at the morphotropic phase boundary (MPB).

As a gangue mineral, talc is usually associated with chalcopyrite. Therefore, the depression of talc is required in the field of sulphide mineral flotation. Herein, the depression mechanism of pullulan in the flotation separation of chalcopyrite from talc was investigated via flotation tests and characterisation techniques, such as Fourier transform infrared analysis (FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The flotation test results showed that chalcopyrite can be selectively separated from talc with 20 mg/L pullulan as a depressant, and that the separation effect remains unaffected when the depressant dosage is increased to 80 mg/L. Additionally, the zeta potential, FTIR and adsorption measurements indicated that pullulan is selectively adsorbed on talc surfaces, and that talc surfaces adsorb more depressants than chalcopyrite. The XPS results indicated that the pullulan adsorption on talc surfaces is physical. The AFM results indicated that pullulan adsorption on talc surfaces forms polymer layers. Therefore, pullulan is considered a potential depressant of talc in the flotation industry.

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Lattice defects typically reduce lattice thermal conductivity, which has been widely exploited in applications such as thermoelectric energy conversion. Here, an anomalous dependence of the lattice thermal conductivity on point defects is demonstrated in epitaxial WO

We describe the magnetic domain structures and magnetoelectric coupling in self-assembled BiFeO3–CoFe2O4 (BFO–CFO) nanocomposite thin films grown on (110)-LaAlO3 substrates, consisting of CFO slab-shaped crystals (nanofins) embedded in a BFO matrix. The nanofins exhibit magnetic single-domain states with in-plane magnetization along their length due to shape and magnetoelastic anisotropies. The piezoresponse of the BFO matrix is affected by applying an in-plane hard axis magnetic field, indicating magnetoelectric coupling within the multiferroic composite. Conversely, an applied electric field leads to the magnetic reversal of a fraction of the nanofins as the strain transferred from the BFO alters the magnetic anisotropy, enabling switching driven by magnetostatic interactions.

Sulfidization followed by xanthate flotation is an effective technique to recover copper oxide minerals. However, the sulfidization mechanism of malachite has not been determined. In this work, the sulfidization mechanism was investigated by microflotation, field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), electron probe X-ray microanalysis (EPMA), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The flotation results showed that sulfide ions at an appropriate concentration could activate malachite flotation while excess sulfide ions could depress this. The depression of malachite flotation by excess sulfide ions was attributed to the residual sulfide species in the liquid. FESEM–EDS showed that sulfidization product grown on the malachite surface was heterogeneously distributed, which was consistent with the EPMA results. The XRD results for the sulfidized malachite samples showed that the amount of sulfidization product was insufficient for detection under flotation-related conditions. By the selective solvent action of sulfuric acid, the sulfidization product was extracted from the sulfidized malachite. The XRD results for the extracts indicated that the sulfidization product comprised djurleite (Cu31S16) and anilite (Cu7S4), which both were compounds of the chalcocite group (Cu2−xS), suggesting transformation of solid Cu2(OH)2CO3 to Cu2−xS on the malachite surfaces during sulfidization. Moreover, the XPS results were consistent with the XRD results. These results demonstrated that sulfidization of malachite is a phase-transition process driven by the solubility difference between Cu2(OH)2CO3 and Cu2−xS. In this case, Cu2−xS phases formation on malachite involves heterogeneous nucleation and growth, and sulfide ions act as a reductant and sulfidizing agent in malachite sulfidization. The copper sulfide grown on malachite radically changed the surface properties of malachite particles, rendering malachite amenable to xanthate flotation. Based on these findings, we present a new formula for malachite sulfidization and a schematic diagram of the sulfidized malachite particle.

Room-temperature ferromagnetism was characterized for thin films of $\mathrm{SrT}{\mathrm{i}}_{0.6}\mathrm{F}{\mathrm{e}}_{0.4}{\mathrm{O}}_{3\text{\ensuremath{-}}\ensuremath{\delta}}$ grown by pulsed laser deposition on $\mathrm{SrTi}{\mathrm{O}}_{3}$ and Si substrates under different oxygen pressures and after annealing under oxygen and vacuum conditions. X-ray magnetic circular dichroism demonstrated that the magnetization originated from $\mathrm{F}{\mathrm{e}}^{2+}$ cations, whereas $\mathrm{F}{\mathrm{e}}^{3+}$ and $\mathrm{T}{\mathrm{i}}^{4+}$ did not contribute. Films with the highest magnetic moment ($0.8\phantom{\rule{0.16em}{0ex}}{\ensuremath{\mu}}_{\mathrm{B}}$ per Fe) had the highest measured $\mathrm{F}{\mathrm{e}}^{2+}$:$\mathrm{F}{\mathrm{e}}^{3+}$ ratio of 0.1 corresponding to the largest concentration of oxygen vacancies $(\ensuremath{\delta}=0.19)$. Postgrowth annealing treatments under oxidizing and reducing conditions demonstrated quenching and partial recovery of magnetism respectively, and a change in Fe valence states. The study elucidates the microscopic origin of magnetism in highly Fe-substituted $\mathrm{SrT}{\mathrm{i}}_{1\ensuremath{-}x}\mathrm{F}{\mathrm{e}}_{x}{\mathrm{O}}_{3\text{\ensuremath{-}}\ensuremath{\delta}}$ perovskite oxides and demonstrates that the magnetic moment, which correlates with the relative content of $\mathrm{F}{\mathrm{e}}^{2+}$ and $\mathrm{F}{\mathrm{e}}^{3+}$, can be controlled via the oxygen content, either during growth or by postgrowth annealing.

Vertically aligned α-Fe2O3 nanopillar arrays (NPAs) were fabricated by thermally oxidizing Fe NPAs on Si, quartz and F-doped SnO2 (FTO) substrates prepared by glancing angle e-beam deposition (GLAD). The photocatalytic activity of these NPAs was evaluated by measuring the photodegradation of crystal violet (CV) and methyl orange (MO) in the presence of H2O2 under visible light irradiation. Moreover, the photoelectrochemical (PEC) performance was also studied. Typically the sample oxidized at 400 °C exhibits both the highest degradation efficiency and photocurrent density compared with those oxidized at other temperatures (e.g. 300 °C, 350 °C, 450 °C, 500 °C). This phenomenon might be attributed to a trade-off between two opposite effects. On the one hand, with the increase of the oxidation temperature, the improvement of NPAs' crystallinity will enhance the photocatalytic performance accordingly. On the other hand, increasing oxidation temperature may cause the reduction of oxygen vacancies on the NPAs' surface, which are regarded as the photoreaction active sites. This will thus degrade the photocatalytic performance.

In the past several decades, dilute magnetic semiconductors, particularly the dilute magnetic oxides have evolved into an important branch of materials science due to their potential application in spintronic devices combining of properties of semiconductors and ferromagnets. In spite of a major effort devoted to the mechanism of ferromagnetism with a high Curie temperature in these materials, it still remains the most controversial research topic, especially given the unexpected d0 ferromagnetism in a series of undoped wide-band-gap oxides films or nanostructures. Recently, an abundance of research has shown the critical role of various defects in the origin and control of spontaneous magnetic ordering, but contradicting views from intertwined theoretical calculations and experiments require more in-depth systematic research. In our previous work, considerable efforts have been focused on two major oxides, i.e. ZnO and ZrO2. This review will present a summary of current experimental status of this defect-driven ferromagnetism in dilute magnetic oxides (DMOs).

Monoclinic HfO2 thin films with intrinsic defects were prepared by annealing in flowing argon. The behavior of the HfO2 films could be manipulated by applying an external magnetic field during annealing processing. Room-temperature ferromagnetism and visible photoluminescence were observed in these un-doped HfO2 films due to the involvement of oxygen vacancies. The results demonstrated that the density of oxygen vacancies in HfO2 films could be controlled by varying the intensity of the magnetic field. This study could facilitate understanding of ferromagnetism origin in un-doped oxides, also suggests an effective way to alter the intrinsic defects in HfO2 to improve its performance.

Undoped ZrO2 thin films are prepared on 〈100〉 Si substrates by reactive DC magnetron sputtering using a Zr target. By controlling the oxygen partial pressure during the deposition process, we can successfully control the phase structure of the as-deposited film, which can be tetragonal, monoclinic or a mixture of them. A magnetic property measurement reveals that phase-dependent d0 ferromagnetism exists in ZrO2 thin films. Specifically, only tetragonal ZrO2 thin films can be room-temperature ferromagnetic. Photoluminescence measurements, X-ray photoelectron spectroscopy analyses and post thermal annealing experiments suggest the d0 ferromagnetism in undoped tetragonal ZrO2 films is mainly driven by oxygen vacancies.

The importance of tuning refractive index in a multilayer antireflection coating (ARC) system can not be denied. In practical applications, regulation of refractive index is complex due to limited choice and availability of appropriate materials for the trilayer AR coating assembly. To overcome this issue, we used a single inorganic material, HfO2, for the construction of a trilayer AR light harvesting moth eye, resembling hierarchical nanostructure coatings, for exploring new generation photovoltaics and optoelectronic devices. In the trilayer AR HfO2 (TAR-H) assembly, using a glancing angle deposition technique (GLAD), the dense bottom layer was steadily changed into a spongy middle layer that further changed to a highly porous top layer micmiking a moth eye, reducing the refractive index of the coating from 1.87 to 1.30. The broadband omnidirectional properties of the TAR-H coating, with superior thermal stability and improved scratch resistance, in the visible wavelength range were experimentally demonstrated. The TAR-H coating on FTO and sapphire substrates achieved reflectance of up to

Lattice defects typically reduce lattice thermal conductivity, which has been widely exploited in applications such as thermoelectric energy conversion. Here, an anomalous dependence of the lattice thermal conductivity on point defects is demonstrated in epitaxial WO3 thin films. Depending on the substrate, the lattice of epitaxial WO3 expands or contracts as protons are intercalated by electrolyte gating or oxygen vacancies are introduced by adjusting growth conditions. Surprisingly, the observed lattice volume, instead of the defect concentration, plays the dominant role in determining the thermal conductivity. In particular, the thermal conductivity increases significantly with proton intercalation, which is contrary to the expectation that point defects typically lower the lattice thermal conductivity. The thermal conductivity can be dynamically varied by a factor of ≈1.7 via electrolyte gating, and tuned over a larger range, from 7.8 to 1.1 W m-1 K-1 , by adjusting the oxygen pressure during film growth. The electrolyte-gating-induced changes in thermal conductivity and lattice dimensions are reversible through multiple cycles. These findings not only expand the basic understanding of thermal transport in complex oxides, but also provide a path to dynamically control the thermal conductivity.

This article presents a kind of high sensitive magnetic transducer which is based on the phase characteristics of giant magnet-impedance (GMI) effect. Then the development process of this new kind of magnetic transducer is discussed with the ideal condition of the GMI sensor elements (the frequency and the amplitude of the excitation current). Compared with the amplitude characteristics of GMI effect, the transducer can make a 10 to 100 times lower frequency. At the ideal condition, the sensor has a sensitivity of 1.6°/Oe, and we can conclude that the sensor has a potential to detect the weak magnetic.

A device for measuring high-TC superconducting transition temperature in a small cryocooler is described which allows a samples temperature to fall steadily from room temperature to 45K. This cryocooler not only meets the high-TC superconductors measurement requirements, but also yields accurate measurement results under ambient conditions. In this device, two measurement methods for measuring high-TC superconducting transition temperature are applied: the electric transport and the AC susceptibility. The former adopts a four-wire method to eliminate the contact resistance between the leads and the sample. During the measurement process the current reversal method for datum processing is applied to eliminate the thermoelectric voltages; this ensures the repeatability error less than 0.4K in the measurement of the superconducting transition temperature. The AC susceptibility method adopts a lock-in amplifier to provide an AC voltage signal for the primary coil, and then lock-in amplifier is used to measure the electrical signals of the secondary coil according to the AC magnetic susceptibility values. The advantage of this device is that by merely changing the position of the sample in the vacuum chamber, the R-T curve and the χ-T curve of a superconducting sample in the same temperature range can be automatically recorded, which provides reliable data for high-TC superconductor transition curve measurement.

The thermal conductivity of self-assembled nanocomposite oxide films consisting of cobalt ferrite (CFO) spinel pillars grown within a single-crystal bismuth ferrite (BFO) perovskite matrix is described as a function of the volume fraction of the spinel. Single phase BFO and CFO had cross-plane thermal conductivities of 1.32 W m−1 K−1 and 3.94 W m−1 K−1, respectively, and the thermal conductivity of the nanocomposites increased with the CFO volume fraction within this range. A small increase (∼5%) in thermal conductivity for the pure CFO phase in the AC-demagnetized state was observed, suggesting possible magnon contributions. Steady state gray-medium based variance-reduced Monte Carlo simulations show consistent trends with experimental data on the dependence of thermal conductivity with the CFO volume fraction.