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The phase transition of Nd2In and Pr2In has been studied and found to be between the first-order and second-order nature. Hardly any hysteresis nor obvious cell volume changes are presented. Concurrently the field-triggered metamagnetism is demonstrated with lambda-like peak on specific heat curve. For the field change of 7 T, giant magnetic entropy changes of 13.2 J kg−1 K−1 and 19.5 J kg−1 K−1 and adiabatic temperature changes of 6.5 K and 7.4 K have been achieved in Nd2In and Pr2In alloys respectively, which is partially contributed by strong magnetoelastic coupling represented by high saturation magnetostriction of ∼450 ppm. Such unique feature is proposed to be originated from the delocalized 5d electrons, as evidenced by the negative magnetoresistance caused by the phase transition.

Novel rare-earth-contained W-based in-plane chemically ordered (W2/3R1/3)2AlC (R = Gd, Tb, Dy, Ho, Er, Tm and Lu) i-MAX phases have been firstly reported. All are identified to be C2/c monoclinic by structural analysis. Magnetic ground state is found to change from linear antiferromagnetism for R = Gd to paramagnetism for R = Lu with gradually decreased ordering temperature with the evolution on magnetic configurations. By exfoliation and delamination, brittle W1.33C MXene fragments have been obtained and demonstrated undesired specific capacitance of 76 F g−1 at 1 A g−1. By making W1.33C/Ti3C2 composite MXene, flexible free-standing paper has been obtained and the specific capacitance is substantially enhanced to 183 F g−1 with good retention, which is the highest performance realized in W1.33C MXene up to now.

Effects of Ga substitutions in R2Al1-xGax (R = Gd, Er) alloys have been studied. Gd2Al1-xGax (x ≤ 0.2) and Er2Al1-yGay (y ≤ 0.3) alloys are found to be crystallized in Co2Si-type orthorhombic structure. With increased Ga substitution for Al, the phase transition temperature is gradually increased. For the field change of 7 T, the maximum of entropy change (-ΔSM) is increased to 14.8 J/kgK and 11.2 J/kgK in Gd2Al0.8Ga0.2 and Er2Al0.7Ga0.3 alloys compared with 11.4 J/kgK and 8.3 J/kgK of Gd2Al and Er2Al alloys. And the relative cooling power is nearly doubled to 699.6 J/kg in Gd2Al0.8Ga0.2 alloy. As increasing Ga substitution, the critical magnetic field for the transition is decreased in Gd2Al1-xGax (x ≤ 0.2) alloys, and the magnetization is increased in Er2Al1-yGay (y ≤ 0.3) alloys. The considerable ΔSM implies that those materials are promising candidates for magnetic cooling.

The crystallographic structure of rare-earth-contained (Mo2/3R1/3)2AlC (R = Gd, Tb, Dy, Ho, Er and Y) i-MAX phases have been verified to be C2/c monoclinic. The magnetic behaviors are varied from antiferromagnetism to non-linear ferromagnetism from R = Gd to Ho in (Mo2/3R1/3)2AlC i-MAX phases due to variant R-R interactions. The capacitance of Mo1.33C@R MXene derived from different (Mo2/3R1/3)2AlC precursors varies from 170 F/g to 228 F/g but can be double by hydrazine monohydrate treatment. The highest one of 431 F/g up to now has been achieved in Mo1.33C@Y-HM MXene, which is caused by the increased fraction of critical -O group evidenced by XPS spectra. Our results illustrate the promising applications in supercapacitor of Mo1.33C MXene derived from R-contained (Mo, R)2AlC i-MAX phases.

The effects of Fe substitution for Ti on the structural and magnetic properties of the (Ti1-xFex)3AlC2(x = 0, 0.025, 0.05, 0.075) MAX phases have been studied. The Fe substitution leads into the expansion along c-axis but shrinkage within ab-plane of the hexagonal unit cell and also the ferromagnetic state at low temperature. The Curie temperature is increased with more Fe substitution. After exfoliation and delamination, their (Ti1-xFex)3C2Tδ 2D MXenes counterparts are obtained with paramagnetic state, which is due to the broken exchange coupling along c-axis resulting from the etching away of Al layer. The best electromagnetic interference properties of − 30 dB within a wide range of frequency with 5.8–26.5 GHz can be achieved in (Ti0.975Fe0.025)3C2Tδ free-standing “paper” made of the corresponding MXene by vacuum-infiltration.

It is highly important to develop ultrastable electrode materials for Li-ion batteries (LIBs), especially in the low temperature. Herein, we report Fe3+-stabilized Ti3C2Tx MXene (donated as T/F-4:1) as the anode material, which exhibits an ultrastable low-temperature Li-ion storage property (135.2 mA h g−1 after 300 cycles under the current density of 200 mA g−1 at −10 °C), compared with the negligible capacity for the pure Ti3C2Tx MXene (∼26 mA h g−1 at 200 mA g−1). We characterized as-made T/F samples via the X-ray photoelectron spectroscopy (XPS), Fourier transformed infrared (FT-IR) and Raman spectroscopy, and found that the terminated functional groups (-O and -OH) in T/F are Li+ storage sites. Fe3+-stabilization makes -O/-OH groups in MXene interlayers become active towards Li+, leading to much more active sites and thus an enhanced capacity and well cyclic stability. In contrast, only -O/-OH groups on the top and bottom surfaces of pure Ti3C2Tx MXene can be used to adsorb Li+, resulting in a low capacity. Transmission electron microscopy (TEM) and XPS data confirm that T/F-4:1 holds the highly stable solid electrolyte interphase (SEI) layer during the cycling at −10 °C. Density functional theory (DFT) calculations further uncover that T/F has fast diffusion of Li+ and consequent better electrochemical performances than pure Ti3C2Tx MXene. It is believed that the new strategy used here will help to fabricate advanced MXene-based electrode materials in the energy storage application.

Metamagnetic phase transition of Mn2-xCrxSb (x = 0.07, 0.09, and 0.11) and Mn2-yVySb (y = 0.1, 0.15) alloys had been studied. More Cr and V substitutions lead into increased phase transition temperature, which is confirmed by differential scanning calorimetry (DSC) measurement. The maximized saturation magnetostriction (λs//) of − 1350 ppm and − 610 ppm under 7 T have been realized in Mn1.93Cr0.07Sb alloy and Mn1.9V0.1Sb alloy, respectively, and gradually decreased with more substitution. Giant negative thermal expansion (NTE) is triggered by metamagnetism. The highest linear coefficient of − 42.4 ppm/K is obtained in Mn1.93Cr0.07Sb alloy, but almost zero expansion is obtained in Mn1.85V0.15Sb alloy. The coincident highest ΔSmax associated with the maximized λs// in both Mn2-xCrxSb (x = 0.07, 0.09, and 0.11) and Mn2-yVySb (y = 0.1, 0.15) systems suggests that the strong magnetoelastic coupling is also beneficial to enhance the magnetic entropy change.

A novel rare-earth-based YCxTδ two-dimensional metal carbide (MXene), with feather-like morphology and hexagonal structure, has been prepared by selective etching of a nanolaminated precursor YAl3C3 non-transition-metal-aluminum-carbides (non-MAX) phase. By analyzing the gas products and first-principle calculation, the chemical reaction is concluded. The YCxTδ MXene shows high reversible gravimetric specific capacity of ~ 84 mAh/g as Li ion battery anode and a specific capacitance of 18 F/g as electrode of super capacitors. These intriguing properties suggest the promising application potentials of high-abundance Y in energy storage 1 .

The single-layer Ta(20 nm)Nd13Fe77B10(100 nm)Ta(20 nm) film was prepared and diffusion-processed by Nd25Cu75(20 nm) and Nd70Cu30(20 nm). The evolutions of microstructure and magnetic properties were comparably studied. By using same amount of diffusion layer, different coercivities were achieved. The coercivity enhancement mechanism was explained phenomenologically by surface defects of Nd2Fe14B grains and estimation of activation volume. It was found that due to the increased Nd composition in grain boundaries, the activation volume was reduced and the local anisotropy was enhanced due to the remedied surface defect. Such dependence was consistent with the coercivity changes.

As the emerging ambient low-cost magnetic refrigeration system, the substitution effects on the magnetic properties and magnetocaloric effects in Al1−xSixFe2B2 (x = 0, 0.1, 0.2, 0.3) and Al1−yGayFe2B2 (y = 0.1 and 0.2) have been studied. The single phase is formed in a wide substitution composition region. All phase transitions in these compounds are of second-order and their Curie temperature (Tc) increases with more Si and Ga substitutions. For a field change of 5 T and 7 T, the maximum of entropy change (ΔSmax) of 4.9 J Kg−1 K−1 and 6.3 J Kg−1 K−1 are obtained and not dependent on the Si substitution amount in Al1−xSixFe2B2. As comparison, by Ga substitution, for the field change of 7 T and 5 T, the ΔSmax have been increased to 7.5 J Kg−1 K−1 and 6 J Kg−1 K−1 respectively. The tunable ambient Tc and considerable ΔSmax suggest that AlFe2B2-based compounds are potential low-cost ambient magnetic refrigeration candidates.

To enhance the magnetocaloric effect of the second-order magnetic phase transition is eagerly sought in the development of practical magnetic refrigeration technology. Here, demonstrated by Dy2In1−xAlx (0 ≤ x ≤ 0.5) system, the max magnetic entropy change is significantly enhanced to 13.4 Jkg−1 K−1 in Dy2In0.7Al0.3 and 10.8 Jkg−1 K−1 in Dy2In0.6Al0.4 alloys compared with 8.8 Jkg−1 K−1 in Dy2In through a field-induced metamagnetic phase transition, which is unconventionally of nonhysteresis confirmed by magnetic measurements. Considering that nonhysteresis metamagnetic transition occurs at the critical composition where hexagonal structure is formed for x ≤ 0.3 while orthorhombic structure for x ≥ 0.4, the origin is ascribed to the lattice distortion.

Fabrication of exchange-coupled nanocomposite magnets has been considered to be the most effective method to achieve the high energy product for advanced permanent magnet applications. In this work, we report a facile auto-combustion synthesis to prepare porous exchange-coupled hard–soft ferrite-based magnetic BaFe8Al4O19−x wt% Co0.6Zn0.4Fe2O4 nanocomposites (where x = 10, 20, 30 and 40), which realize an effective exchange-coupled interaction when the x value is less than 30. Compared with BaFe8Al4O19, the optimized nanocomposite with 20% Co0.6Zn0.4Fe2O4 shows a 70.3% increase in Ms and a 60.4% enhancement in Mr and maintains a high Hc value of 8.8 kOe. The work demonstrates that the auto-combustion synthesis is a promising approach for the fabrication of high-performance ferrite-based permanent magnets.

The magnetocaloric effects in Sn-substituted Mn2Sb1-xSnx system (x = 0.1, 0.2, 0.3) have been studied. With more Sn content, metamagnetic phase transition temperature (Tt) is increased with gradually reduced Curie temperature, thermal hysteresis and the maximum of magnetic entropy change (ΔSmax). By hydrostatic pressure of 2.5 kbar, Tt is lowered but ΔSmax is enhanced from 4.2 JKg−1K−1 to ∼5.5 Jkg−1K−1 in Mn2Sb1-xSnx (x = 0.1, 0.2) ingots. The uniaxial magnetocrystalline anisotropy is found in all Mn2Sb1-xSnx ingots and abnormally increased with elevated temperature, leading to the abnormal coercivity-temperature dependence in the corresponding ribbons. The microstructure of the ribbons is sensitively dependent on Sn composition. Our work demonstrates that high ΔSmax tuned by hydrostatic pressure and high magnetocrystalline anisotropy can be realized together in Mn2Sb1-xSnx system, which may help the development of such bifunctional alloy exhibiting refrigerating capability as well as the hard magnetic properties simultaneously.

D022-structure and L10-structure had been realized in Mn100-xGax (x = 67.5, 70, 72.5 and 75) annealed ribbons and identified by X-ray diffraction and transmission electron diffraction. The Mn-dependent Curie temperature and coercivity had been studied. By applying hydrostatic pressure of 2.5 kbar, the coercivity had been enhanced in D022-structured ribbons but a kink was observed on the hysteresis loop of L10-structured ribbon. The different effects of hydrostatic pressure on magnetic coupling were also observed in the ribbons possessing D022-and L10-structure. They were explained by the affected magnetocrystalline anisotropy in D022-and L10-structures under hydrostatic pressure, which was further verified by the first-principles calculations. Our work demonstrated the feasibility of tuning coercivity of hard magnetic materials by hydrostatic pressure besides of the conventional microstructural optimization.

The lattice distortion of tetragonal Cu 2 Sb-type Mn 1.95 V 0.05 Sb alloy was realized by Li interstitial doping or hydrostatic pressure. The metamagnetic transition temperature was decreased and the thermal hysteresis was widened by either depressurization or increasing interstitial Li content. Its effects on magnetic entropy changes ( ∆ S ) and critical field had been studied. Thanks to moderate hydrostatic pressure, the beneficial enhancement of maximum of ∆ S was achieved in tetragonal Cu 2 Sb-type Mn 1.95 V 0.05 Sb alloy. Our experiment demonstrates that the interatomic distance between Mn II -Mn II sites and the electronic density surrounding Mn II sites are critical for metamagnetic phase transition.

Magnetic properties as well as microstructural evolution were firstly studied in Cr(20 nm)/Ce13Fe79B8(100 nm)/Cr(20 nm) benchmark film and the film diffusion-processed with Ce70Cu30(11 nm), Nd(11 nm) and Nd70Cu30(11 nm) alloy layer. The coercivities were still as low as 0.6 T with poor squareness even after diffusion process. By Nd substitution for Ce in Ce13 − xNdxFe79B8 magnetic layer, squareness was greatly improved. The coercivity was tunable between 0.6 T and 2.34 T and maximum energy product was ranged from 83.4 kJ/m3 to 204.6 kJ/m3 depending on the Nd composition in Cr(20 nm)/Ce13 − xNdxFe79B8(100 nm)/Nd(11 nm)/Cr(20 nm) (x = 3, 6, 9) films. Transmission electron microscopy observation showed the columnar 2:14:1 phase grains with typical core/shell microstructure and rare-earth-rich grain boundaries. Our results demonstrated the promising commercialization potential of Ce-Fe-B based magnets with performance between ferrites and Nd-Fe-B magnets.

High-purity RAl3C3 phases (R = Nd, Gd, Tb, Dy, Ho, Er and Tm) have been synthesized and all crystallized in hexagonal structure with the space group (#194) P63/mmc. Lattice parameters are decreased from R = Nd to R = Tm due to lanthanide contraction. Two nonlinear antiferromagnetic states are found in NdAl3C3 phase. While simple ferromagnetic state is observed for R = Gd, Tb, Ho and Er cases. A high coercivity of 0.45 T has been achieved in TbAl3C3 phase at 4 K indicating the uniaxial magnetocrystalline anisotropy. Before entering into paramagnetic state, DyAl3C3 phase undergoes the complex magnetic phase transition with increasing temperature. All these phase transitions are of second-order due to nonhysteresis.

By hetero-structural alloying ferromagnetic hexagonal Ho2In with antiferromagnetic orthorhombic Ho2Al, the magnetic and structural changes have been observed in Ho2In1-xAlx (0 ≤ x ≤ 0.4) alloys. At the critical composition x = 0.1, the highest maxima of magnetic entropy change of 16.3 Jkg-1K−1 and the adiabatic temperature change of 6.5 K have been obtained via an unconventional hysteresis-free metamagnetic phase transitionm, which is higher than 9 Jkg-1K−1 and 5.4 K in Ho2In benchmark alloy undergoing second-order phase transition. Such increment is associated with the intensified magnetoelastic coupling. The deeper origin is proposed to be from the delocalized 5d electrons of rare-earth atoms by external field since the magnetoresistence is also maximized at the critical composition. The hetero-structural alloying strategy is demonstrated to be effective to intensify the MCE effect without causing the undesirable hysteresis.

Chemical bonding has been regarded as an effective modification strategy to enhance the electrochemical performance of MXenes for Li-ion batteries (LIBs). However, the in-depth mechanism, especially concentrating on the regulation of chemical bond, is rarely explored. Herein, we design an atomically dispersed Fe in Ti3C2Tx MXene (Fe-Ti3C2Tx) by a doping route and the underlying mechanism of high-capacity LIBs is comprehensively investigated. Density functional theory (DFT) calculations reveal that unsaturated O coordination can be induced by electron transfer on Fe–O bond, which enables improved Li-ion adsorption on the surface of Fe-Ti3C2Tx nanosheet during charge/discharge process. The experimental observations from X-ray photoelectron spectroscopy (XPS) confirm the successful introduction of Fe atoms into intrinsic structure of Ti3C2Tx MXene, and the X-ray absorption spectroscopy (XAS) data verify the electron transfer of Fe–O bond. Moreover, Fe-Ti3C2Tx electrode exhibits greatly enhanced electrochemical performance (564.9 mAh g−1 at 50 mA g−1 under −10 °C), surpassing that of pristine Ti3C2Tx (77 mAh g−1). The cycling stability of Fe-Ti3C2Tx over 500 cycles (418.8 mAh g−1 at 200 mA g−1 under −10 °C). This work is expected to provide a guideline to develop brand-new MXene-based electrode materials with high-capacity for energy storage.

A polycrystalline AlN underlayer prepared by reactive sputtering has been used for the preparation of SmCo 3.5 Cu 0.5 thin films with varying thickness. The out-of-plane (OOP) texture is confirmed by X-ray diffraction and magnetic measurements. A highest ambient coercivity of 2.92 T is obtained with good squareness. The microstructure shows columnar grains and a high density of stacking faults. Additionally, a twinning structure is found. The thermal stability of the coercivity of AlN-buffered SmCo 3.5 Cu 0.5 thin films has been investigated in correlation with the microstructure. The present work demonstrates the great potential of using AlN underlayer for the preparation high-performance Sm-(Co,Cu) thin films with OOP texture.

The tetragonal Cu 2 Sb-type Mn 1.8 Cu 0.2 Sb alloy was prepared by solidification under zero field and high magnetic field of 12 T. No thermal hysteresis was observed. High-magnetic-field (HMF) solidification led into c -axis texture in Mn 1.8 Cu 0.2 Sb alloy. Moreover, the severity of metamagnetic transformation in a Mn 1.8 Cu 0.2 Sb alloy was steepened and the resultant magnetic entropy change was enhanced. The exchange bias at low temperature was observed. Our work demonstrated the pronounced influences of HMF solidification on the crystallographic orientation, metamagnetic phase transformation and the magnetic exchange couplings.

Mn 1.95 Cu 0.05 SbB x (x = 0, 0.06 and 0.1) alloys had been prepared and B interstitial effects on metamagnetic transition were studied. The metamagnetic transition temperature was reduced and thermal hysteresis was widened by higher B concentration. The saturation magnetization and the magnetic entropy change were increased by moderate amount of B addition. However, too high B composition led into the sluggish metamagnetic transition. By relating with crystallographic structure, our results further indicated that the electron density of the atoms at MnⅡ position plays critical role on influencing the metamagnetic transition in tetragonal Cu 2 Sb-type Mn 1.95 Cu 0.05 Sb alloys.

Effects of B4C addition on the microstructure and magnetic properties of FePt and FePt-C thin films have been studied. A high coercivity of 2.11 T with good squareness is achieved by B4C addition. By analyzing the mechanism and different isolation effects of B4C and C as segregants, a double-layer approach has been developed and a coercivity of 1.96 T is achieved with column-like FePt grains. The grain size and the size distribution are not deteriorated substantially compared with the single-layer case. These results indicate that addition of B4C as segregant is beneficial for the modification of microstructure and magnetic properties.

Fabrication of exchange-coupled nanocomposite magnets has been considered to be the most effective method to achieve the high energy product for advanced permanent magnet applications. In this work, we report a facile auto-combustion synthesis to prepare porous exchange-coupled hard-soft ferrite-based magnetic BaFe8Al4O19-x wt% Co0.6Zn0.4Fe2O4 nanocomposites (where x = 10, 20, 30 and 40), which realize an effective exchange-coupled interaction when the x value is less than 30. Compared with BaFe8Al4O19, the optimized nanocomposite with 20% Co0.6Zn0.4Fe2O4 shows a 70.3% increase in Ms and a 60.4% enhancement in Mr and maintains a high Hc value of 8.8 kOe. The work demonstrates that the auto-combustion synthesis is a promising approach for the fabrication of high-performance ferrite-based permanent magnets.

The importance of the solid electrolyte interphase (SEI) layer for enhanced Li-ion storage has been well established, but primary understanding of the chemical components and structure of SEI layer on MXene-based electrodes remains incomplete. Here, we characterized the morphology and components of SEI layer on Ti3C2Tx and Ti3C2Tx/Fe2O3 electrode materials through combination of X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and transmission electron microscopy (TEM). The results show the SEI layer formed on pillar-structured Ti3C2Tx/Fe2O3 is dense and intact after long cycling, while the SEI layer on Ti3C2Tx electrode is noncontinuous. The pillar-structured Ti3C2Tx/Fe2O3 exhibits significantly enhanced capacity of 449.6 mAh g−1 at 300 mA g−1 after 100 cycles compared with Ti3C2Tx (140.2 mAh g−1) owing to the intact SEI layer with friendly chemical components. This work elaborates a recognition for SEI layer in MXene-based electrode, which provides a useful strategy for further SEI engineering.

By gradually substituting Al for In in Gd2In1−xAlx (0.4 ≤ x ≤ 1) system, the hexagonal structure for Gd2In1−xAlx (x ≤ 0.6) is gradually evolved into orthorhombic one for x ≥ 0.7. The phase transition temperature is monotonously decreased. At the critical composition of x = 0.7, the second-order phase transformation in hexagonal Gd2In1−xAlx (x ≤ 0.6) is evolved into the first-order-like metamagnetic one without conventional hysteresis in orthorhombic Gd2In1−xAlx (x ≥ 0.7), leading into the enhanced magnetic entropy change and adiabatic temperature change. A lambda-like anomaly on the Cp-T curves is also caused. Due to being close to the phase borderline separating hexagonal and orthorhombic structure, such enhanced magnetocaloric effect is considered to be from the greatly distorted lattice.

Ce 13 Fe 79 B 8 ribbons were prepared by melt-spinning and diffusion-processing with minor amounts of Nd 70 Cu 30 and Nd 80 Ag 20 alloys. Low coercivities of ∼0.2 T were obtained in the as-melt-spun ribbons and annealed ribbons although Ce-rich grain boundaries were observed. By diffusion process, the coercivity was increased to be over 0.7 T, due to the formation of magnetically hardened (Nd,Ce) 2 Fe 14 B shell. The chemistry of Ce-rich grain boundary phase was studied and face-center-cubic crystallographic structure was determined by nano-beam diffraction. The Henkel plots confirmed the enhanced magnetocrystalline anisotropy due to the formation of core/shell microstructure.

The Nd 13.5 Fe 79.5 B 7 bulk magnets were prepared by melt-spinning followed by hot-compaction and post-annealing. In the optimized benchmark magnet, the diffusion process was carried out by using La 70 Cu 30 , Nd 70 Cu 30 and Dy 70 Cu 30 alloy powders. Elementary distribution showed that Nd was coexistent with La but immiscible with Dy in the grain boundary (GB) regions. Crystallized GB phase was observed. The components of coercivity enhancement contributed from ferromagnetic decoupling, remedied grain surface and magnetically hardened grain surface were analyzed. Our results demonstrated that remedied grain surface and magnetically hardened grain surface contribute mostly to the enhanced coercivity, instead of ferromagnetic decoupling.

By hetero-structural alloying antiferromagnetic orthorhombic Er2Al and ferromagnetic hexagonal Er2In which both undergo the second-order phase transition, an unconventional nonhysteretic metamagnetic phase transition is observed at the critical composition of x = 0.2 in Er2In1-xAlx (0 ≤ x ≤ 0.4) system. The magnetic entropy change and adiabatic temperature change is enhanced to 16.9 Jkg−1K−1 and 7.2 K in Er2In0.8Al0.2 with the largest saturation magnetostriction of -1117 ppm under 7 T. By correlating with specific heat and magnetotransport measurement, the origin of such unique nonhysteretic metamagnetism is assumed to be from the field-induced reconstruction of 5d subband of rare-earth elements.

The effects of Ta substitution on the phase transition have been studied in Hf1-xTaxFe1.98 (x = 0.125, 0.13, 0.135) alloys with kagome-type lattice. Increased Ta substitution leads into the reduced metamagnetic transition temperature (Tt). The nature of such phase transition is also changed from second-order type to the weak first-order one, suggested by the gradually observed hysteresis. The magnetic entropy change (ΔS) is meanwhile enhanced from 3.04 J kg−1 K−1 to 3.4 J kg−1 K−1. Such enhanced magnetocaloric effects are strongly correlated with the enhanced magneto-elastic effect, which is further confirmed by the maximized saturation magnetostriction (λs//) of ~1700 ppm near the Tt of Hf0.865Ta0.135Fe1.98 alloy. The concurrence of maximized ΔSmax and λs// suggests the strong magneto-elastic coupling during phase transition and the high linear co-efficiency of negative thermal expansion can be triggered in Fe-deficient Hf0.865Ta0.135Fe1.98 alloy.

A novel rare-earth-based YCxTδ two-dimensional metal carbides (MXene), with feather-like morphology and hexagonal structure, has been prepared by selective etching of a nanolaminated precursor YAl3C3 non-transition-metal-aluminium-carbides (non-MAX) phase. By analyzing the gas products and first-principle calculation, the chemical reaction is concluded. The YCxTδ MXene shows high reversible gravimetric specific capacity of ~84 mAh/g as Li ion battery anode and a specific capacitance of 18 F/g as electrode of super capacitors. These intriguing properties suggest the promising application potentials of high-abundance Y in energy storage.

In this study, an effective method was developed for the isolation and enrichment of Ginkgo biloba extract by continuous chromatography system. The adsorption and desorption ratio of flavonoids as main index, the best macroporous resin was screened out from six resins by static adsorption and desorption tests. At the same time the adsorption and desorption parameters were optimized by dynamic adsorption and desorption tests. Under optimal parameters, five operations consisting of loading, washing, desorbing, regenerating, and balancing were integrated across the continuous chromatography system for the purpose of refining 66 L of crude extract solution. The results were as follows, 198.22 g of Ginkgo biloba extracts was produced, which contained 65.83 g of flavonoids and 15.44 g of lactones. The content of flavonoids and lactones increased from 2.76 and 0.72% in the crude extract to 33.21 and 7.79%, with a recovery yield of 91.26 and 81.21%. Methodology validation showed that the proposed method had high stability and reproducibility. Compared with the traditional macroporous resin method, the proposed method had a short processing time and low solvent consumption. Our studies indicated that the newly developed method is an effective procedure for the isolation and enrichment of Ginkgo biloba extract.

Voltage gating is essential to the computational ability of neurons. We show this effect can be mimicked in a solid-state nanopore by functionalizing the pore interior with a redox active molecule. We study the integration of an active biological molecule-a quinone-into a solid state nanopore, and its subsequent induced voltage gating. We show that the voltage gating effect mimics biological gating systems in its classic sigmoidal voltage response, unlike previous synthetic voltage gating systems. Initially, the quinone undergoes a reduction due to radicals in the bulk solution, and is converted to the hydroquinone state. Upon deprontonation the hydroquinone then acts as a charged nanomechanical arm, which opens the channel under the applied potential. We establish that the quinone gains a single net charge when the pH inside of the nanopore reaches its pKa value, and explore factors that influence the net pH in the middle of the pore. Using a combination of theory, experiment and simulation, we conclude that concentration polarization and a shift of the pH inside of the channel is the main cause of this gating effect.

An analogue of DPP, dithienylbenzodipyrrolidone (DTBDPD), was successfully synthesized. Several D–A copolymers, with different electron donating capability donor unit (fluorene, difluorene, dithienosilole, and dithienopyrrole) and DTBDPD acceptor, were prepared by means of Suzuki and Stille coupling reaction. The optical and electrochemical properties were demonstrated through UV–vis–NIR absorption and cyclic voltammetry (CV). All polymers showed near-infrared or even infrared absorption and deeper LUMO levels, as low as −3.80 eV.