Crystallographic phase identifier of a convolutional self-attention neural network (CPICANN) on powder diffraction patterns.

Spectroscopic data, particularly diffraction data, are essential for materials characterization due to their comprehensive crystallographic information. The current crystallographic phase identification, however, is very time consuming. To address this challenge, we have developed a real-time crystallographic phase identifier based on a convolutional self-attention neural network (CPICANN). Trained on 692 190 simulated powder X-ray diffraction (XRD) patterns from 23 073 distinct inorganic crystallographic information files, CPICANN demonstrates superior phase-identification power. Single-phase identification on simulated XRD patterns yields 98.5 and 87.5% accuracies with and without elemental information, respectively, outperforming JADE software (68.2 and 38.7%, respectively). Bi-phase identification on simulated XRD patterns achieves 84.2 and 51.5% accuracies, respectively. In experimental settings, CPICANN achieves an 80% identification accuracy, surpassing JADE software (61%). Integration of CPICANN into XRD refinement software will significantly advance the cutting-edge technology in XRD materials characterization.

Low field controllable continuous spin switching in the thulium-ytterbium single crystal.

We report the spin reorientation transition (SRT) and the low field controllable continuous spin switching (SSW) of the Tm0.75Yb0.25FeO3 (TYFO) single crystal in this study. The SRT, characterized by the transition from Γ2(Fx, Cy, Gz)-Γ4(Gx, Ay, Fz), occurs within the temperature range of 20-27 K. Under an external magnetic field of 50 Oe, the SSW occurs along the c-axis at approximately 98 K due to the reversal of Tm3+ magnetic moment induced by the magnetic coupling change between Tm3+ and Fe3+, transitioning from a parallel to an antiparallel alignment. Notably, a continuous SSW is observed along the a-axis at low temperatures, which has not been previously reported in rare earth orthoferrites. This unique behavior can be easily manipulated by low magnetic fields within the temperature range of 2-20 K. Both the spin reorientation transition and spin switching phenomena in the TYFO single crystal arise from interactions between rare earth ions and iron ions and can be effectively regulated by applied low magnetic fields, making it a promising material for low-field spin devices.

Enhanced proton conductivity by guest molecule exchange in an acylamide-functionalized metal-organic framework.

Metal-organic frameworks (MOFs) as types of proton conductive materials have attracted much attention. Here, an acylamide-functionalized 3D MOF, [Ni3(TPBTC)2(stp)2(H2O)4]·2DMA·32H2O, has been successfully constructed via combining Ni(NO3)2, TPBTC (TPBTC = benzene-1,3,5-tricarboxylic acid tris-pyridin-4-ylamide) and 2-H2stp (2-H2stp = 2-sulfoterephthalic acid monosodium salt) under solvothermal conditions. Single-crystal X-ray diffraction revealed that there are uncoordinated guest DMA molecules in the pores of the compound. On removal of guest DMA molecules, the proton conductivity of the compound increased to 2.25 × 10-3 S cm-1 at 80 °C and 98% RH which is about 110 times that of the original material. It is hoped that this work can provide essential insight for designing and obtaining improved crystalline-state proton conducting materials by considering the influences of guest molecules on proton conduction properties of porous materials.

Chemical and Biological Properties of Biochanin A and Its Pharmaceutical Applications.

Biochanin A (BCA), an isoflavone derived from various plants such as chickpea, red clover and soybean, is attracting increasing attention and is considered to have applications in the development of pharmaceuticals and nutraceuticals due to its anti-inflammatory, anti-oxidant, anti-cancer and neuroprotective properties. To design optimised and targeted BCA formulations, on one hand there is a need for more in-depth studies on the biological functions of BCA. On the other hand, further studies on the chemical conformation, metabolic composition and bioavailability of BCA need to be conducted. This review highlights the various biological functions, extraction methods, metabolism, bioavailability, and application prospects of BCA. It is hoped that this review will provide a basis for understanding the mechanism, safety and toxicity of BCA and implementing the development of BCA formulations.

Architecture Design and Catalytic Activity: Non-Noble Bimetallic CoFe/fe3 O4 Core-Shell Structures for CO2 Hydrogenation.

Non-noble metal catalysts now play a key role in promoting efficiently and economically catalytic reduction of CO2 into clean energy, which is an important strategy to ameliorate global warming and resource shortage issues. Here, a non-noble bimetallic catalyst of CoFe/Fe3 O4 nanoparticles is successfully designed with a core-shell structure that is well dispersed on the defect-rich carbon substrate for the hydrogenation of CO2 under mild conditions. The catalysts exhibit a high CO2 conversion activity with the rate of 30% and CO selectivity of 99%, and extremely robust stability without performance decay over 90 h in the reverse water gas shift reaction process. Notably, it is found that the reversible exsolution/dissolution of cobalt in the Fe3 O4 shell will lead to a dynamic and reversible deactivation/regeneration of the catalysts, accompanying by shell thickness breathing during the repeated cycles, via atomic structure study of the catalysts at different reaction stages. Combined with density functional theory calculations, the catalytic activity reversible regeneration mechanism is proposed. This work reveals the structure-property relationship for rational structure design of the advanced non-noble metallic catalyst materials with much improved performance.

Three layered cucurbit[6]uril-based metal-organic rotaxane networks functionalized by sulfonic groups for proton conduction.

Three new cucurbit[6]uril (CB[6])-based metal-organic rotaxane networks (MORNs) (named CUST-711, CUST-712, and CUST-713) functionalized by a sulfonic group (-SO3H) have been designed and synthesized via a hydrothermal method. All three compounds exhibited similar two-dimensional (2D) wave layer structures. Their stability under different temperature and relative humidity conditions has been investigated and all the compounds showed excellent stability. Furthermore, their proton conduction properties were also discussed in detail. Due to different structures and sulfonic group sites, the three compounds exhibited different proton conduction abilities of which CUST-712 exhibited an intrinsic relatively high proton conductivity (1.75 × 10-4 S cm-1 at 85 °C and 97% relative humidity). These results provide ideas for the design and synthesis of functional CB[6]-based metal-organic rotaxane frameworks (MORFs) as proton conducting materials.

Low field control of spin switching and continuous magnetic transition in an ErFeO3 single crystal.

The magnetic behavior of a rare-earth orthoferrite ErFeO3 single crystal can be controlled by low magnetic fields from a few to hundreds of Oe. Here we investigated a high-quality ErFeO3 single crystal in the temperature range of 5-120 K, with two types of spin switching in the field-cooled-cooling (FCC) and field-cooled-warming (FCW) processes below the temperature of the spin reorientation (SR) transition from Γ4 to Γ2 at 98-88 K. The magnitude of the applied magnetic fields can regulate two types of spin switching along the a-axis of the ErFeO3 single crystal but does not affect the type and temperature range of the SR transition. An interesting "multi-step" type-II spin switching is observed in FCW under low magnetic fields (H < 18 Oe) just below the SR transition temperature, which is associated with the interaction and the change of magnetic configurations from rare-earth and iron magnetic sublattices. When the magnetic field is lower than 15 Oe, the type-II spin switching in the FCW process gradually changes to a continuous magnetic transition along the a-axis of the ErFeO3 single crystal. As the magnetic field is reduced to less than 17 Oe, the type-I spin switching in the FCW process also transforms into a continuous magnetic transition. Understanding the magnetic reversal effects will help us explore the potential applications of these magnetic materials for future information devices.

Evolution of Superconducting Properties in Fe1.1Se0.8Te0.2 Films Before and After Structure Avalanche.

By preparing a series of high-quality Fe1.1Se0.8Te0.2 films on the CaF2 substrate via pulsed laser deposition, we reveal the evolution of the structure as well as the superconductivity with the film thickness. We have found that there exists a threshold thickness above which the critical temperature Tc reaches its optimal value of 23.18 K with large activation energy, promising for high-field technological applications. Most importantly, the thick films have been found in a metastable state due to the fragile balance between the increased strain energy and the large compressive stress. Once the balance is broken by an external perturbation, a unique structure avalanche happens with a large part of the film exfoliated from the substrate and curves out. The exfoliated part of the film remains a single phase, with its lattice parameter and Tc recovering the bulk values. Our results clearly demonstrate the close relation between the compressive stress of the film/substrate interface and the high critical temperature observed in FeSeTe films. Moreover, this also provides an efficient way to fabricate free-standing single-phase FeSeTe crystals in the phase-separation regime.

Emergence of exchange bias field in FeS superconductor with cobalt-doping.

Among all the iron-based superconductors, the 11 series has the simplest layered structure but exhibits rich physical phenomenon. In this work, we have synthesized Fe1-xCoxS single crystals with tetragonal structure and studied their structure and magnetic properties. Magnetic susceptibility measurements indicate that the cobalt doping would suppress superconductivity and even introduce weak ferromagnetism besides antiferromagnetism. Scanning electron microscopy study reveals that the Co-doped samples exhibit intrinsic phase separation. Moreover, magnetic force microscopy measurement shows no magnetic domain in Fe1-xCoxS, indicating that neither phase is pure ferromagnetic. The coexistence of ferromagnetism and antiferromagnetism leads to the relatively large exchange bias field. Since the exchange bias effect has been widely used in the field of information storage, spin-valves, and magnetic tunnel junctions, our study provides another option for further application.

Doping tuned spin reorientation and spin switching in praseodymium-samarium orthoferrite single crystals.

We investigate the detailed analysis of the magnetic properties in a series of Pr1-xSmxFeO3single crystals fromx= 0 to 1 with an interval of 0.1. Doping controlled spin reorientation transition temperatureTSRΓ4(Gx,Ay,Fz) to Γ2(Fx,Cy,Gz) covers a wide temperature range including room temperature. A 'butterfly'-shape type-I spin switching with 180° magnetization reversal occurs below and above the magnetization compensation points inx= 0.4 to 0.8 compounds. Interestingly, in Pr0.6Sm0.4FeO3single crystal, we find an inadequate spin reorientation transition accompanied by uncompleted type-I spin switching in the temperature region from 138 to 174 K. Furthermore, a type-II spin switching appears at 23 K, as evidenced from the magnetization curve in field-cooled-cooling (FCC) mode initially bifurcate from zero-field-cooled (ZFC) magnetization curve at 40 K and finally drops back to coincide the ZFC magnetization value at 23 K. Our current research reveals a strong and complex competition between Pr3+-Fe3+and Sm3+-Fe3+exchange interactions and more importantly renders a window to design spintronic device materials for future potential applications.

Spin-orbit coupling in magnetoelectric Ba3(Zn1-xCox)2Fe24O41 hexaferrites.

The Z-type hexaferrites Ba3(Zn1-xCox)2Fe24O41 (x = 0.2, 0.4, 0.6, 0.8, defined as Z1-Z4) were synthesized by a sol-gel method. With increasing cobalt concentration, the origin of magnetoelectric (ME) coupling and the effects of crystal parameters, occupation of ions, and magnetocrystalline anisotropy (MCA) on ME current were studied systematically. The mechanism of magnetic phase transition, revealing the evolution of the magnetic order in the temperature range of 10-400 K, was discussed in detail. Our results suggest that the ferroelectricity of Z1-Z4 originates from both inverse Dzyaloshinskii Moriya (DM) interaction and p-d hybridization mechanism. In particular the ME coupling property is only dominated by p-d hybridization with spin-orbit coupling. This study provides an effective way to improve the ME coupling property of hexaferrites, which have potential applications in the design of new electronic devices.

Large easy-plane anisotropy induced spin reorientation in magnetoelectric materials (Co4-x Mn x )Nb2O9.

Neutron powder diffraction experiments were carried out on the magnetoelectric compound series (Co4-x Mn x )Nb2O9 (x = 0, 1, 2, 3, 3.5, 3.9, 3.95 and 4) from base temperature to above their Néel temperatures. Their magnetic structures were analysed by using the irreducible representation analysis and Rietveld refinement method. Similar to Co4Nb2O9, the compounds with x ⩽ 3.9 have noncollinear in-plane magnetic structures (Γ6) with magnetic moments lying purely in the ab plane with certain canting angles. Mn4Nb2O9 has a collinear antiferromagnetic structure (Γ2) with magnetic moments aligning along the c axis. The compound of x = 3.95 shows two magnetic phases in the magnetization, which was confirmed to have the Γ2 magnetic structure above 60 K and develop a second Γ6 local phase in addition to the main Γ2 phase due to doping. This study indicates 2.5 at% Co2+ doping is sufficient to alter the collinear easy-axis magnetic structure of Mn4Nb2O9 into the noncollinear easy-plane magnetic structure, which is attributed to the large easy-plane anisotropy of Co2+ and relative small Ising-like anisotropy of Mn2+. The doping effects on the Néel temperature and occupancy are also discussed.

Nonlinear magnetoelectric effect in paraelectric state of Co4Nb2O9 single crystal.

We report the structural, magnetoelectric (ME), magnetic and electric control of magnetic properties in Co4Nb2O9 (CNO) single crystal. A detailed ME measurement reveals a nonlinear ME effect instead of a linear ME effect in CNO single crystal. By fitting the magnetization-electric field (M-E) curve, it can be found that the linear ([Formula: see text]) and quadratic (γ) coefficients equal to ~8.27 ps/m and ~-6.46 ps/MV for upper branch, as well as ~8.38 ps/m and ~6.75 ps/MV for the lower branch. More importantly, a pronounced response was observed under a small cooling magnetic field, which cannot even cause the spin flop. This suggests a magnetoelectric effect can occur at paraelectric state for CNO single crystal. Furthermore, we also found that the magnetization of every axis responds to electric field applied along a-axis, but fails to do so when the electric field is applied c-axis. Such findings supply a direct evidence to the magnetic structure and ME coupling mechanism indirectly reflected by our neutron experiment.

[Comparative study of clinical effects of VCu IUD and TCu380A IUD were used on women who once been done cesarean section].

OBJECTIVE: To study and compare the clinical efficacies and characteristics of VCu intrauterine device (IUD) and TCu380A IUD in childbearing-aged women with previous cesarean section so as to provide rationales for an informed choice of contraceptive methods. METHODS: According to their physical status, a total of 400 women undergoing previous cesarean section were randomly provided VCu IUD and TCu380A IUD from February 2008 to August 2009. These healthy women were had no contraindication to IUD. The volunteers required voluntarily the placement of IUD. Then all of them were followed up for 3, 6 and 12 months. RESULTS: At Month 12, the pregnant rate with IUD in situ of VCu and TCu380A IUD were 1.02% and 4.64%, expulsion rate 0 and 3.1% and withdrawing rate 1.02% and 4.13% respectively. The pregnant rate was significantly different (P < 0.05); VCu showed a lower expulsion and withdrawing rate than that in TCu380A (P < 0.05); the continuation rate of VCu was higher than that of TCu380A (P < 0.05). CONCLUSION: VCu offers a better efficacy of contraception with a lower expulsion and withdrawing rate, a higher continuation rate and a simpler placement method.