In near-field communication (NFC) antennas, soft magnetic ferrites are usually applied as a substrate to reduce eddy current loss and increase magnetic field coupling. For this purpose, the applied ferrites are required to have high permeability and saturation magnetization together with low magnetic loss and dielectric loss. However, for most soft magnetic ferrites, it is difficult to meet all the requirements. Herein novel Ni–Zn ferrite ceramics co-doped by Ho³⁺ and Co²⁺ ions with chemical formula Ni_0.5−xZn_0.5Ho_0.02Co_xFe_1.98O₄ (x = 0–0.2) were designed and prepared to balance these needs on the basis of molten salt synthesis with metal nitrates as raw materials and potassium hydroxide (KOH) as the precipitation agent and molten salt precursor. After the substitution of Ho³⁺, the saturation magnetization and initial permeability decrease, but with further doping of Co²⁺, the saturation magnetization gradually increases, while the initial permeability continues to decrease. When x = 0.1, the sample will have the lowest dielectric constant, magnetic and dielectric loss, as well as the highest Curie temperature (305 ℃). Moreover, the acquired Ni–Zn ferrites have been applied simulatively in NFC antennas, revealing that the device manufactured with the optimal Ni_0.4Zn_0.5Ho_0.02Co_0.1Fe_1.98O₄ ferrite ceramics would have significantly improved performance at 13.56 MHz with low leakage and long transmit distance of magnetic field. Therefore, the Ni_0.4Zn_0.5Ho_0.02Co_0.1Fe_1.98O₄ ferrite ceramics would be a good candidate for NFC antenna substrates.

Owing to the robust Li-ion storage properties induced by entropy stabilization effect, transition metal (TM)-based high-entropy oxides (HEOs) are promising electrode materials for high-performance Li-ion batteries (LIBs). In this study, a six-component Zn_0.5Co_0.5Mn_0.5Fe_0.5Al_0.5Mg_0.5O₄ spinel-structured HEO (denoted as 6M-HEO, where M = Zn, Co, Mn, Fe, Al, and Mg) was synthesized using a facile coprecipitation method. When used as an anode of the LIBs, its stable high-entropy nanostructures exhibit high specific capacity (290 mAh·g⁻¹ at a current density of 2 A·g⁻¹), ultra-long cycling stability (maintained 81% of the initial capacity after 5000 cycles), and outstanding rate performance. Such excellent performance can be attributed to two factors. Firstly, its high-entropy structure can reduce the stress caused by intercalation and avoid volume expansion of the HEO nanostructures. As a result, the cyclic stability was significantly enhanced. Secondly, owing to the unique element selection in this study, four active elements (Zn, Co, Mn, and Fe) were incorporated in inactive MgO and Al₂O₃ matrice after the first discharge process, which would allow such high-entropy materials to withstand the rapid shuttle of Li ions.

MoS₂ nanoflowers are favored for their potential in the production of elemental sulfur due to abundant surface area and good catalytic performance for reducing SO₂. A novel synthetic strategy of porous Al₂O₃ supported on the MoS₂ with nanoflower structure was proposed. The effects of preparation concentration, calcination atmosphere, and Al₂O₃ contents on the growth of catalysts with nanoflower structure were systematically studied via X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and Brunauer–Emmett–Teller (BET). The surface area was increased to 295.502 m²/g and the amount of Lewis acid on the surface of the Al₂O₃/MoS₂ catalyst was increased by adjusting the ratio of Al/Mo. The porous and nanoflower structures of Al₂O₃/MoS₂ catalysts promoted the sulfur selectivity without inhibiting the catalytic performance of MoS₂. The conversion of SO₂ and the selectivity of sulfur were 100% and 92% after 100 h life evaluation.

Novel scheelite structures of Li₂Ca(WO₄)₂, Li₂Ca₂(WO₄)(SiO₄), and LiCa₂(WO₄)(PO₄) fluorescent materials were successfully prepared using a high-temperature solid-phase process. The compounds were characterized by X-ray diffraction and energy dispersive spectroscopy. The tests revealed that the substitution of [WO₄]^2- by [SiO₄]^4- or [PO₄]^3- tetrahedron in tungstate had no significant influence on the crystal structure of the Li₂Ca(WO₄)₂. When Dy³⁺ ions were introduced as an activator at an optimum doping concentration of 0.08 mol%, all of the as-prepared phosphors generated yellow light emissions, and the emission peak was located close to 576 nm. Replacing [WO₄]^2- with [SiO₄]^4- or [PO₄]^3- tetrahedron significantly increased the luminescence of the Li₂Ca(WO₄)₂ phosphors. Among them, the LiCa₂(WO₄)(PO₄):0.08Dy³⁺ phosphor had the best luminescence properties, decay life (τ = 0.049 ms), and thermal stability (87.8%). In addition, the as-prepared yellow Li₂Ca(WO₄)₂:0.08Dy³⁺, Li₂Ca₂(WO₄)(SiO₄):0.08Dy³⁺, and LiCa₂(WO₄)(PO₄):0.08Dy³⁺ phosphor can be used to fabricate white light emitting diode (LED) devices.

The critical requirements for the environmental barrier coating (EBC) materials of silicon-based ceramic matrix composites (CMCs) include good tolerance to harsh environments, thermal expansion matches with the interlayer mullite, good high-temperature phase stability, and low thermal conductivity. Cuspidine-structured rare-earth aluminates RE₄Al₂O₉ have been considered as candidates of EBCs for their superior mechanical and thermal properties, but the phase transition at high temperatures is a notable drawback of these materials. To suppress the phase transition and improve the phase stability, a novel cuspidine-structured rare-earth aluminate solid solution (Nd_0.2Sm_0.2Eu_0.2Y_0.2Yb_0.2)₄Al₂O₉ was designed and successfully synthesized inspired by entropy stabilization effect of high-entropy ceramics (HECs). The as-synthesized HE (Nd_0.2Sm_0.2Eu_0.2Y_0.2Yb_0.2)₄Al₂O₉ exhibits a close thermal expansion coefficient (6.96×10^-6 K^-1 at 300-1473 K) to that of mullite, good phase stability from 300 to 1473 K, and low thermal conductivity (1.50 W·m^-1·K^-1 at room temperature). In addition, strong anisotropic thermal expansion has been observed compared to Y₄Al₂O₉ and Yb₄Al₂O₉. The mechanism for low thermal conductivity is attributed to the lattice distortion and mass difference of the constituent atoms, and the anisotropic thermal expansion is due to the anisotropic chemical bonding enhanced by the large size rare-earth cations.

Rare-earth tantalates and niobates (RE₃TaO₇ and RE₃NbO₇) have been considered as promising candidate thermal barrier coating (TBC) materials in next generation gas-turbine engines due to their ultra-low thermal conductivity and better thermal stability than yttria-stabilized zirconia (YSZ). However, the low Vickers hardness and toughness are the main shortcomings of RE₃TaO₇ and RE₃NbO₇ that limit their applications as TBC materials. To increase the hardness, high entropy (Y_1/3Yb_1/3Er_1/3)₃TaO₇, (Y_1/3Yb_1/3Er_1/3)₃NbO₇, and (Sm_1/6Eu_1/6Y_1/6Yb_1/6Lu_1/6Er_1/6)₃(Nb_1/2Ta_1/2)O₇ are designed and synthesized in this study. These high entropy ceramics exhibit high Vickers hardness (10.9-12.0 GPa), close thermal expansion coefficients to that of single-principal-component RE₃TaO₇ and RE₃NbO₇ (7.9×10^-6-10.8×10^-6 ℃^-1 at room temperature), good phase stability, and good chemical compatibility with thermally grown Al₂O₃, which make them promising for applications as candidate TBC materials.

Rare-earth (RE) doping can greatly enhance the voltage gradient of ZnO-based varistors, and their nonlinear coefficient, leakage current, energy absorption capability, through-current capability and residual voltage can also be improved to certain extent. In this review, the progress on RE-doped ZnO-based varistor materials in recent years was summarized. The mechanism of RE doping on the electrical performance of ZnO varistors was analyzed. The issues in exploring new ZnO-based varistor materials by RE doping were indicated, and the development trends in this area were proposed.