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Multilayer film with an interfacial buffer layer made of different material has been show to improve the film properties. However, it is not well understood if similar benefits may be achieved by multiple deposition of GZO without the addition of new interfacial materials. Here we prepared single-, double-, and triple-deposited GZO films on glass substrate (preheated to 180 °C) by atmosphere pressure plasma jet (APPJ). We found that the triple-deposited film exhibits overall enhancement over the single-deposited film in deposition rate (110 nm/min) and the key properties, such as resistivity (9.4 × 10 −4 Ω cm), crystallite size (16 nm), carrier concentration, mobility, and band gap. In particular, the resistivity and deposition rate are significantly improved by 33% and 35%, respectively. The results are attributed to the mitigation of lattice-mismatch between the film and the glass substrate by the bottom thin GZO film. The findings may also be applied to other deposition methods with moving nozzle or moving stage such as spray pyrolysis. [ABSTRACT FROM AUTHOR]

A prominent laser crystal Nd 3+ :NaLu(MoO 4 ) 2 with dimension of 25 × 20 × 8 mm 3 was successfully grown from a flux of Na 2 Mo 2 O 7 by the mean of top-seeded solution growth technique. The crystal phase was confirmed by the XRD powder diffraction. The results of the DSC measurements indicate that the melting point of this crystal is 1060 ± 5 °C and that the crystal will decompose into the compounds of Na 2 MoO 4 and Lu 2 (MoO 4 ) 3 when the temperature is above its melting point. The hardness of the crystal is about 440 VDH. The crystal has broad absorption and emission cross-sections. The largest absorption cross-sections are 11.48 × 10 −20 cm 2 and 4.05 × 10 −20 cm 2 at about 817 nm for the π- and σ-polarizations with the full width at half-maximum (FWHM) of 10 nm and 16 nm, respectively. The emission cross-sections reach to 12.31 × 10 −20 cm 2 at 1064 nm for the π-polarization and 6.22 × 10 −20 cm 2 at 1069 nm for the σ-polarization. The lifetime is estimated to be 127.6 μs. The laser experiment has also been performed and the highest slope efficiency is about 30.6%. All the results demonstrate that Nd 3+ :NaLu(MoO 4 ) 2 crystal may be a potential laser gain medium for the diode laser pumping. [ABSTRACT FROM AUTHOR]

An Nd 3+ :KBaY(MoO 4 ) 3 crystal with dimensions of 27 × 21 × 8 mm 3 was grown by the TSSG method. KBaY(MoO 4 ) 3 crystal with disordered structure crystallizes in the monoclinic system with space group C2/c. The spectral properties of KBaY(MoO 4 ) 3 crystal have been investigated. It exhibits broad absorption and emission bands, which is caused by its disordered structure and distorted Y(Nd) O 8 polyhedron. Nd 3+ :KBaY(MoO 4 ) 3 crystal has large values of peak absorption and emission cross-sections. The fluorescence quantum efficiency η is up to 97.3%. Therefore, the combination of all the optical parameters favorably distinguishes the Nd 3+ :KBaY(MoO 4 ) 3 crystal from other Nd-doped crystals and makes it as a promising laser material for DPSSL application. [ABSTRACT FROM AUTHOR]

• The unique wounded CNTs were generated from the pyrolysis of the precursor without the addition of carbon sources. • The embedded Co 9 S 8 nanoparticle was obtained easily and required no further treatment or addition of metal sources. • This structure design strategy could be easily extended. • The Co 9 S 8 @NCNHP/S cathode exhibits the great electrochemical performance. [Display omitted] Lithium-sulfur (Li-S) battery is one of the most promising candidates for next-generation rechargeable batteries, while the volume expansion, severe shuttle effect, and sluggish reaction kinetics hinder its practical applications. Herein, a novel structure composed of Co 9 S 8 nanoparticles embedded in a N-doped carbon nanotube hollow polyhedron (Co 9 S 8 @NCNHP) is designed to address these issues. Co 9 S 8 nanoparticles can efficiently accelerate the kinetics of redox reaction and anchor the polysulfides, enhancing the electrochemical performance of cathodes. Furthermore, NCNHP can accommodate the huge volume expansion and block the diffusion of lithium polysulfides. Benefiting from this rational design, the Co 9 S 8 @NCNHP/S cathode exhibits a high initial discharge capacity of 1186 mAh·g−1 with a decay rate of 0.1% per cycle during 200 cycles at 0.2 C. An initial discharge capacity of 780 mAh·g−1 as well as a decay rate of 0.15% per cycle after 200 cycles can be obtained at a sulfur loading of 3.2 mg·cm−2. This strategy based on the combination of rational structure design and electrocatalysis could advance the cathode construction in Li-S batteries. [ABSTRACT FROM AUTHOR]

Hydrogen production by electrochemical water splitting is one of the best ways to store renewable energy. Metal organic framework (MOF)-derived non-precious metal catalysts are an effective idea for large-scale commercialization and electrolysis of water for hydrogen production. Herein, we have synthesized Ni,Mo bimetallic selenide MoSe 2 @NiSe 2 heterojunctions with hollow core-shell using a selenization reaction to combine MoSe 2 with NiMOF-derived NiSe 2. The spherical clusters of MoSe 2 prevents the agglomeration and sintering of NiSe 2 and shorten the electron transfer distance form MoSe 2 to NiSe 2. The electron flow between the transition metals Ni and Mo after the selenization reaction, which alters the electronic structure of NiMOF and MoSe 2. NiSe 2 derived from NiMOF provides more active center as well as better conductivity to accelerate the electron transfer rate. Thus facilitating the HER catalytic process. Electrochemical analysis confirmed that the activity of Hydrogen evolution reaction (HER) of MoSe 2 @NiSe 2 was significantly increased in 0.5 M H 2 SO 4 , with an overpotential of 187 mV at 10 mA cm−2 and a tafel slope of 71.43 mV dec−1. This work provides a new route for the design and preparation of the NiMOF-based catalysts in HER. [Display omitted] • MoSe 2 @NiSe 2 heterojunctions with hollow core-shell was synthesized. • The HER activity of MoSe 2 @NiSe 2 was significantly increased. • The core-shell interface of MoSe 2 @NiSe 2 exhibiting sufficient active sites. • NiSe 2 and MoSe 2 synergistically accelerate the charge transfer rate. [ABSTRACT FROM AUTHOR]

Single-crystalline H 2 Ti 6 O 13 nanofibers have been prepared from Li 2 Ti 6 O 13 nanobelts as precursor templates via hydrogen/lithium ion-exchange under hydrothermal condition. Then, H 2 Ti 6 O 13 nanofibers are successfully converted into anatase TiO 2 nanofibers with high-density nanocavities after calcination at 700 °C for 10 h in air. Both H 2 Ti 6 O 13 and anatase TiO 2 nanofibers are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. When evaluated for photocatalytic properties for the degradation of Rhodamine B under ultraviolet light irradiation, anatase TiO 2 nanofibers exhibit higher photocatalytic behavior than H 2 Ti 6 O 13 nanofibers. Furthermore, the photocatalytic efficiency of anatase TiO 2 nanofibers with high-density nanocavities is higher than that of anatase TiO 2 nanoparticles with an average diameter of 40 nm, which may be attributed to its one-dimensional morphology and high-density nanocavities. [ABSTRACT FROM AUTHOR]

Novel visible-light-induced Bi 2 WO 6 photocatalysts were successfully synthesized by a molten salt method. The effects of the calcination temperature and the salt amount were investigated. The results indicated that the presence of molten salts significantly enhanced the surface area of the powders from 7.08 to a maximum of 21.09 m 2 g −1 , and higher calcination temperature improved the crystallinity but decreased the surface area of the powders. When the precursor powders were calcinated at 300 °C for 8 h with the presence of 10 times weight of salts, the as-synthesized Bi 2 WO 6 powders exhibited the highest degradation efficiency in the photodegradation of RhB under the visible light irradiation and the reaction contant was more than 10 times that of the samples synthesized without adding salts. [ABSTRACT FROM AUTHOR]

In this paper, porous NiO nanoflake arrays@V 2 O 5 nanoparticles (PNFAs@VNPs) composite is fabricated on Ni foam through a facile hydrothermal process. The PNFAs@VNPs composite has an ordered array structure, a large active surface, and favorable physical stability. Based on the CV profile, the specific capacitance can achieve 950 F g−1 and remain stable at 95.8 % of the original value after 5000 loops. When the PNFAs@VNPs composite is assembled into a symmetric supercapacitor, the energy density can reach 67.0 W h kg−1 at a power density of 550 W kg−1. Even if the power density rises to 11,000 W kg−1, the energy density can still be held at 25.3 W h kg−1. The high supercapacitive property of the PNFAs@VNPs composite is owed to the synergic action of the PNFAs and VNPs. The PNFAs@VNPs composite with the advantages of battery-type and capacitive-type pseudocapacitances has higher charge transfer dynamics, making it a potential supercapacitive electrode material. [Display omitted] • Porous NiO nanoflake arrays (PNFAs) is successfully prepared on nickel foam. • V 2 O 5 nanoparticles (VNPs) are loaded on the PNFAs to form a hierarchical structure. • The PNFAs@VNPs has the advantages of Faraday and intercalation type pseudocapacitor. • The PNFAs@VNPs shows a specific capacitance of 950 F g−1at 5 mV s−1. • The PNFAs@VNPs supercapacitor has an energy density of 67.0 W h kg−1 at 550 W kg−1. [ABSTRACT FROM AUTHOR]

Abstract: Bi2−x Ag3x S3 (x =0–0.06) polycrystals were fabricated by mechanical alloying (MA) and spark plasma sintering (SPS). The phase, microstructure, electrical and thermal transport properties were investigated with a special emphasis on the influence of Ag doping content. All the Bi2−x Ag3x S3 powders can be indexed as single phase with an orthorhombic symmetry, a second AgBi3S5 phase in SPSed bulks occurs as the doping contents x ≥0.02, which enhances the electrical conductivity, resulting in improvement of electrical transport properties for Bi2−x Ag3x S3 bulk samples. A maximum ZT value reached 0.23 at 573K for the Bi1.99Ag0.03S3 sample, which is 130% higher than that (0.11) of the pure Bi2S3. [Copyright &y& Elsevier]

V 2 O 5 nanobelt arrays (VNBAs) is fabricated on Ni foam by using an easy hydrothermal route and then NiO nanosheet arrays (NNSAs) is grown on VNBAs by using a simple chemical bath deposition approach to form VNBAs/NNSAs composite. It is found that the monocrystalline VNBAs with a lamellar structure is uniformly distributed on nickel foam and the polystalline NNSAs with a close packed structure is closely covered on the VNBAs. CV, GCD, EIS and CA electrochemical techniques are used to test the supercapacitive properties of the VNBAs/NNSAs composite. The single electrode displays a high specific capacity of 875 F g−1, a good cycling stability of 96.1%, a small charge transfer resistance of 1.32 Ω and a rapid ion diffusivity of 2.5 × 10−8 cm2 s−1. The symmetric supercapacitor combined by the VNBAs/NNSAs displays a large energy density of 120.1 W h kg−1 at 400 W kg−1 and it retains 68.3 W h kg−1 at 8000 W kg−1. The VNBAs/NNSAs composite with high electrochemical performance is a potential supercapacitor electrode material. [Display omitted] • The V 2 O 5 nanobelt arrays (VNBAs) is successfully prepared on a nickel foam. • The NiO nanosheet arrays (NNSAs) is compounded on the VNBAs to form a hierarchy. • The VNBAs/NNSAs shows a high specific capacitance of 875 F g−1 at 5 mV s−1. • The VNBAs/NNSAs has an energy density of 120.1 W h kg−1 at 400 W kg−1. • The high performance of the VNBAs/NNSAs are ascribed to its synergistic effect. [ABSTRACT FROM AUTHOR]

Abstract WO 3 nano-fibers with super large aspect ratio are synthesized on a Cu conductive current collector by using a simple hydrothermal method. The as-prepared WO 3 nano-fibers can accommodate a large number of electrolyte ions and provide a rapid route for the migration of electrons and electrolyte ions due to its direct growth, high specific surface area, and one dimensional (1D) pipeline structure. The WO 3 nano-fibers exhibit excellent cyclic reversibility (98% at 1.0 A g−1), good cycling stability (93% after 5000 cycles), high specific capacitance (436 F g−1 at 1.0 A g−1) and low charge transfer resistance (29 Ω). After the WO 3 nano-fibers are assembled into a symmetric supercapacitor, the symmetric supercapacitor device has a wide effective operating range of 0–1.8 V and high energy density of 99.0 W h kg−1 at the power density of 450 W kg−1. The good electrochemical performances of as-prepared WO 3 nano-fibers make it an attractive candidate for high energy storage systems and promising supercapacitor electrode material. Graphical abstract Image 1 Highlights • WO 3 nano-fibers with super large aspect ratio are prepared directly on a Cu foil. • The WO 3 nano-fibers exhibit a high specific capacitance of 436 F g−1 at 1.0 A g−1. • The WO 3 nano-fibers have a high energy density of 99.0 W h kg−1 at 450 W kg−1. • The good properties of WO 3 nano-fibers are ascribed to their special structure. [ABSTRACT FROM AUTHOR]

Abstract Transparent gallium-doped zinc oxide films were deposited on large area (117 mm × 185 mm) glass substrates by atmospheric pressure plasma jet method, using two different enclosure conditions—with and without side opening boundary. The opening allows gas exchange between the growth ambient and outside atmosphere. The spatial resistivity distribution was apparently influenced by the air flow field. The case with side opening has higher overall non-uniformity, and the film near the opening has the highest resistivity, caused by considerable reduction in carrier concentration (−32%) and mobility (−15%). Computer fluid dynamics simulations show that air was drawn in, through the side opening, from outside atmosphere, resulting in a much higher oxygen mass fraction (+50%) near the opening. As such, the film near the opening was deposited in O-rich conditions. The degradation of electrical conductivity in O-rich conditions cannot be explained by oxygen vacancies. We suggest that it is due to the formation of dopant-defect complex Ga Zn −V Zn (the lowest formation energy) and reduction of hydrogen impurity (reduced hydrogen partial pressure) in O-rich conditions. Therefore, the tool enclosure, gas flow field, and scanning trajectory must be carefully designed to achieve minimum resistivity non-uniformity on large-area substrates. Highlights • Large-area GZO film deposited on 180 °C glass in open air by atmospheric pressure plasma jet. • Ambient gas flow field affects spatial resistivity distribution, which correlates with oxygen mass fraction distribution. • The film deposited in O-rich conditions exhibits much lower carrier concentration (−32%) and Hall mobility (−15%). [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) porous ZnMn 2 O 4 thin films on nickel foam substrates have been successfully synthesized through electrostatic spray deposition (ESD) method followed by an annealing process for lithium-ion battery anodes. These films exhibit excellent cycling performance with a reversible capacity of around 982 mAh g −1 after 100 cycles at 400 mA g −1 . The ZnMn 2 O 4 films also display good rate capability with 455 mAh g −1 at 5 A g −1 . The superior battery performances of ZnMn 2 O 4 films are ascribed to 3D porous ZnMn 2 O 4 film directly deposited on Ni foam, which can offer effective empty space to accommodate the large volume variation during cycling, increase reaction sites, and improve the electron transport. The ESD strategy is facile, cost-effective, which can be potentially utilized to construct other 3D porous mixed transition-metal oxides materials as well. [ABSTRACT FROM AUTHOR]

SnO 2 /polypyrrole (SnO 2 /PPy) hollow spheres were fabricated by a liquid-phase deposition method using colloidal carbon spheres as templates followed by an in-situ chemical-polymerization route. The obtained SnO 2 /PPy composite particles had a size of 610–730 nm. The thickness of inner shell (SnO 2 ) and outer shell (PPy) for composites was about 35 and 90 nm, respectively. As an anode for lithium ion batteries, the SnO 2 /PPy composites electrode showed superior rate capability and excellent long-term cycling performance. After a long-term cycling of 600 cycles at different current densities, a capacity of 899 mAh g −1 was achieved at the current density of 100 mA g −1 for SnO 2 /PPy composites. The excellent electrochemical performance was attributed to the synergistic effect between the PPy coating layer and the hollow SnO 2 spheres, which guaranteed vast lithium storage sites, good electronic conductivity, fast lithium ion diffusion, and sufficient void space to buffer the volume expansion. [ABSTRACT FROM AUTHOR]

In this work, the Bi 2 Se 3 /Mo 3 Se 4 composite is obtained through electrochemical activation of Bi 2 Se 3 /MoSe 2 composite, which has been synthesized by an ordinary hydrothermal reaction closely followed by selenization process. The Bi 2 Se 3 /Mo 3 Se 4 composite appears good electrochemical property as the negative electrode material for sodium ion batteries (the stable reversible capacity is 409 (346) mAh g−1 at 100 (1000) mA g−1). The outstanding electrochemical property can be attributed to the unique Bi 2 Se 3 /Mo 3 Se 4 composite architecture, in which Bi 2 Se 3 is responsible for offering a high capacity, and Mo 3 Se 4 is responsible for improving electrochemcial stability. Moreover, the small particle sizes for Bi 2 Se 3 /Mo 3 Se 4 resulting from the amorphous to crystalline transitions during cycling is also the cause of the increased stability of the electrode. The design of the Bi 2 Se 3 /Mo 3 Se 4 composite provides a potential tactics to construct other metal selenides composites for sodium-ion battery anode. • Bi 2 Se 3 /Mo 3 Se 4 composite was synthesized by convenient strategy. • Bi 2 Se 3 /Mo 3 Se 4 composite exhibits excellent cycling performance for SIBs anode. • Bi 2 Se 3 /Mo 3 Se 4 composite shows good rate capability for SIBs anode. [ABSTRACT FROM AUTHOR]

In this paper, four NiO nano-arrays with different morphology on nickel foam were synthesized by a hydrothermal approach. It is found that the porous single crystal NiO nanoflake array (PNFA) holds superior electrochemical properties, better than the other three samples. The specific capacitance of the PNFA obtained from the cyclic voltammetry curve was 716 F g−1 and that derived from the galvanostatic charge-discharge curve was 589 F g−1 in three-electrode system. The cycling stability of the PNFA could retain as high as 92.4% after 5000 cycles. When the PNFA was assembled into a symmetric supercapacitor, the PNFA//PNFA device exhibited an energy density of 39.3 W h kg−1 (at 550 W kg−1) and could retain 13.2 W h kg−1 (at 11,000 W kg−1) in two-electrode system. Furthermore, the SEM, XRD, TEM and XPS results prove that the PNFA is a special porous single crystal structure, which combines the advantages of the cross-linked single crystal structure for facilitating electron transfer and the porous structure providing more interfaces for insertion/exit of electrolyte ions from the active material. It indicates that the PNFA is a potential electrode material for supercapacitors. [Display omitted] • Porous single crystal NiO nanoflake array (PNFA) is directly grown on nickel foam. • The PNFA is prepared by a facile hydrothermal method following an annealing process. • The PNFA combines the advantages of porous material and single crystal material. • The PNFA shows a specific capacitance of 716 F g−1 at a scan rate of 5 mV/s. • The PNFA//PNFA supercapacitor has an energy density of 39.3 W h kg−1 at 550 W kg−1. [ABSTRACT FROM AUTHOR]

• The effects of Sc, Y and Zr on the performances and microstructure evolution of Al-0.7Mg-0.6Si-0.2Ce alloys were studied. • An excellent combination of strength, elongation and electrical conductivity was achieved with the addition of Sc and Y. • The strengthening and electrical resistance mechanism of the studied alloys were revealed by statistical calculation. [Display omitted] In order to achieve the compatibility between excellent mechanical properties and good electrical conductivity of Al-Mg-Si alloys, detailed investigation was carried out to understand the microstructure evolution and their influences on performances of different Al-0.7Mg-0.6Si-0.2Ce-X (X Sc, Y and Zr) alloys prepared by casting, homogenization, hot extrusion, solution and aging treatments. Under aging state, Ce can form a large number of micron-sized AlCeSi and a few AlCeFeSi phase. The strength increased to 334 MPa as a result of decreased grain size and improved precipitation effect and the electrical conductivity increased up to 53.53%IACS because of lower solute Si atoms. The β" precipitates were coarsened and consequently the volume fracture was largely reduced due to the presence of Sc element, leading to the decreased strength of 311 MPa. The more solute Mg, Si and Sc atoms increased the degree of free electron scattering and the electrical conductivity decreased to 51.86%IACS. It is also found that Sc significantly enhanced the elongation of the alloy from 11.8% to 18.0%, which might be attributed to the formation of Al 3 Sc and (Al, Si) 3 Sc phases. The addition of Y raised the electrical conductivity of Al-Mg-Si-Ce alloy to 55.79%IACS by ameliorating the volume fraction and distribution of β" precipitates and decreasing the solute Si atoms. The co-addition of Sc and Y inherited the advantages of such two alloys. The ultimate tensile strength, elongation, electrical conductivity of Al-0.7Mg-0.6Si-0.2Ce-0.2Sc-0.1Y alloy processed by aging treatments is 336 MPa, 19.4% and 53.11%IACS, respectively. [ABSTRACT FROM AUTHOR]

Abstract: The spectroscopic properties of the Dy3+:LiLa(MoO4)2 crystal prepared by the Czochralski method, have been investigated so as to assess its potentialities for direct yellow laser operation upon excitation with blue–violet or near UV laser diodes. Optical absorption, excitation, emission and fluorescence decay measurements have been performed at room temperature. An intense yellow emission band with favorably high yellow-to-blue luminescence intensity ratio has been observed in the visible region, and relevant parameters for laser applications have been determined in accordance with the Judd–Ofelt theory and Füchtbauer–Ladenburg formula. Based on analysis of Dy3+ concentration dependence of fluorescence lifetime, the energy transfer among Dy3+ ions by the dipole–dipole interaction has been found to be responsible for the fluorescence self-quenching of the 4F9/2 upper laser level at higher dopant concentration. The prospect of the Dy3+:LiLa(MoO4)2 crystal for the realization of efficient yellow laser systems has been discussed. [Copyright &y& Elsevier]

Abstract: The optical properties of a locally disordered Tm3+:Li2Gd4(MoO4)7 crystal have been investigated extensively to assess its feasibility of efficient ultrafast laser operation in the 2μm spectral region. The main spectroscopic parameters relevant to laser applications have been evaluated by analyzing the polarized absorption spectra using the Judd–Ofelt theory. The cross-relaxation mechanisms between Tm3+ levels have been applied to analyze the lifetimes of the 3F4, 3H4, and 1G4 manifolds. The potential for producing subpicosecond laser pulses has been discussed on the basis of the calculated emission and gain cross-sections around 2μm wavelength. The crystal exhibits broad optical bandwidths, large absorption/emission cross sections, and a long 3F4 fluorescence lifetime. All these features indicate that the Tm3+:Li2Gd4(MoO4)7 crystal is a promising gain medium for tunable and ultrafast (fs) pulse lasers. [Copyright &y& Elsevier]

• Highly efficient Ca 3 Y 2 Ge 3 O 12 :Cr3+ phosphors have been synthesized. • The excitation wavelength matches the blue LED chip. • The abroad emission peaked at 800 nm due to Cr3+ in six-coordinated Y3+ site. Near-infrared phosphor (NIR) integrated light-emitting diode (LED) has ideal application prospects in the fields of food inspection and medical imaging. Herein, we have synthesized a garnet-type Ca 3 Y 2 Ge 3 O 12 :Cr3+ NIR phosphor using solid state reaction method. Broadband NIR emission ranging from 700 to 1100 nm with a peak located at 800 nm indicates a weak crystal field strength for Cr3+, which occupies the six-coordinated Y3+ site. Moreover, the phosphor has satisfactory luminous intensity showing 81%/10% internal/external quantum efficiency and excellent luminescence thermal stability. Our work provides an excellent NIR phosphor choice for NIR LED devices. [ABSTRACT FROM AUTHOR]

In this study, we report a facile in situ synthesis of hierarchical NiO/NiFe 2 O 4 sub-microcubes by annealing Ni 3 [Fe(CN) 6 2 sub-microcubes fabricated via a one-step solution-precipitation method. The temperature-dependent magnetization curves show that there exists a collective freezing of the moments of interface spin clusters at T B ≈ 296 K , which further indicates the appearance a coupling interaction between the ferrimagnetic NiFe 2 O 4 and antiferromagnetic NiO nanoparticles. Furthermore, hysteresis loops measurements reveal the existence of an exchange bias effect in the NiO/NiFe 2 O 4 composite system. Interestingly, no training effect of exchange bias is observed, which indicates that the magnetic pinning interaction between NiFe 2 O 4 and NiO is stable and robust. Exchange bias field shows an exponential dependence on temperature and vanishes at about 150 K, which reveals the strong coupling interaction does not improve effectively the thermal stability of exchange bias effect in the current system. The scanning electron microscope (SEM) image of as-synthesized NiO/NiFe 2 O 4 sub-microcubes and hysteresis loops (M − H) under zero-field-cooled (ZFC) and field-cooled (FC) modes measured with a magnetic field of 1 kOe between ± 50 kOe at 2 K. The inset is the central part of M − H loops showing an obvious shift of FC-loop along field axis. Image 1 • NiO/NiFe 2 O 4 sub-microcubes are synthesized by annealing Ni–Fe PBA sub-microcubes. • NiO/NiFe 2 O 4 sub-microcubes exhibit an exchange bias effect. • Exchange bias field shows an exponential dependence on the temperature. • No training effect of exchange bias is observed in NiO/NiFe 2 O 4 sub-microcubes. [ABSTRACT FROM AUTHOR]