Gd2O3nanoparticles were synthesized from the commercial bulk Gd2O3 powders via a simple electrochemical method. The synthesized powders were characterized by means of X-ray powder diffraction(XRD),scanning electron mi...Gd2O3nanoparticles were synthesized from the commercial bulk Gd2O3 powders via a simple electrochemical method. The synthesized powders were characterized by means of X-ray powder diffraction(XRD),scanning electron microscopy(SEM), transmission electron microscopy(TEM) and Fourier transform infrared(FTIR) spectroscopy. The effects of solution p H on the morphological features of the sample were studied. The strategy developed in this study offers significant advantages for the synthesis of Gd2O3 nanoparticles from the bulk Gd2O3 powders compared with the conventional routes. From SEM observations, the size of the Gd2O3 nanoparticles is estimated to be significantly smaller than70 nm.展开更多
A facile compositional tuning by Sb and Cu addition is performed to generate engineered defects in GeTe alloys with ultra-low thermal conductivity.Substitution of Sb and Cu at the Ge-site enhances the power factor due...A facile compositional tuning by Sb and Cu addition is performed to generate engineered defects in GeTe alloys with ultra-low thermal conductivity.Substitution of Sb and Cu at the Ge-site enhances the power factor due to the optimization of carrier concentration while maintaining the convergence of the valence bands.Furthermore,complex multi-dimensional defect structures including 0D(0-dimensional)substituted Sb_(Ge)and Cu_(Ge),2D twin and inversion boundaries,3D herringbone structures,3D embedded nanostructures,and 3D Cu-rich coherent precipitates are generated,which significantly reduce the lattice thermal conductivity benefitting from a collective phonon scattering.Due to this simultaneous manipulation of electronic and thermal transport properties,a maximum thermoelectric figure of merit(zT)of 1.4 was obtained at 723 K.展开更多
基金financially supported by the Nuclear Science and Technology Research Institute of Iran
文摘Gd2O3nanoparticles were synthesized from the commercial bulk Gd2O3 powders via a simple electrochemical method. The synthesized powders were characterized by means of X-ray powder diffraction(XRD),scanning electron microscopy(SEM), transmission electron microscopy(TEM) and Fourier transform infrared(FTIR) spectroscopy. The effects of solution p H on the morphological features of the sample were studied. The strategy developed in this study offers significant advantages for the synthesis of Gd2O3 nanoparticles from the bulk Gd2O3 powders compared with the conventional routes. From SEM observations, the size of the Gd2O3 nanoparticles is estimated to be significantly smaller than70 nm.
基金supported by grants from the National Research Foundation(NRF)of Korea(No.2021R1A4A2001658)funded by the Korean government(MSIT).
文摘A facile compositional tuning by Sb and Cu addition is performed to generate engineered defects in GeTe alloys with ultra-low thermal conductivity.Substitution of Sb and Cu at the Ge-site enhances the power factor due to the optimization of carrier concentration while maintaining the convergence of the valence bands.Furthermore,complex multi-dimensional defect structures including 0D(0-dimensional)substituted Sb_(Ge)and Cu_(Ge),2D twin and inversion boundaries,3D herringbone structures,3D embedded nanostructures,and 3D Cu-rich coherent precipitates are generated,which significantly reduce the lattice thermal conductivity benefitting from a collective phonon scattering.Due to this simultaneous manipulation of electronic and thermal transport properties,a maximum thermoelectric figure of merit(zT)of 1.4 was obtained at 723 K.
