Doping Sn into the Cu2Te lattice can synergistically enhance the power factor and decrease thermal conductivity, leading to remarkably optimized zTs. The lone pair electrons from the 5s orbital of Sn can increase the DOS near the Fermi level of Cu2Te to promote PF and reduce κe by decreasing the carrier concentration. This study explores a scalable strategy to optimize the thermoelectric performance for intrinsically highly degenerate semiconductors.

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Nd 2 Fe 14 B ∕ α - Fe nanocomposites were prepared using a melt-spinning method, subsequent annealing treatment, and ball milling. The complex permittivity and permeability of the composites were measured in the 0.5–18 and 26.5–40GHz frequency ranges. The permeability spectra of the Nd2Fe14B∕α-Fe nanocomposites exhibit relaxation and resonance type characteristic in the 0.5–18 and 26.5–40GHz frequency ranges, respectively. The resonance frequency (fr) of Nd10Fe78Co5Zr1B6 nanocomposite is 30GHz due to the large anisotropy field (HA). However, the resonance frequency of the Nd2Fe14B∕α-Fe sample is lower than that of Nd2Fe14B, due to the decrease of HA induced by the exchange interaction between hard and soft magnetic phases. These samples also showed good microwave absorption performance (reflection loss: <−20dB) in 9, 17, and 35–38GHz with matching thicknesses of 2, 1.2, and 0.37mm, respectively. Therefore, Nd2Fe14B∕α-Fe nanocomposites are thought to be a potential candidate for thinner microwave absorbers not only in the centimeter wave but also in the millimeter wave band.

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Hierarchical porous copper bulk can be fabricated through chemical dealloying of porous CuAl intermetallics under free corrosion conditions. The obtained precursor porous CuAl intermetallics and as-dealloyed hierarchical porous copper were characterised using X-ray diffraction, a field-emission scanning electron microscope and energy dispersive X-ray spectroscopy. It was found that the hierarchical porous copper can be easily prepared by this method. The dealloying solution will dramatically influence the morphology of the resultant hierarchical porous materials. As a result, trimodal porous copper composite material and bimodal porous copper can be achieved after being dealloyed in NaOH and HCl solutions, respectively. Therefore, the mechanisms of the evolution of hierarchical pores structure are also discussed.

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