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Nanodiamonds of different sizes doped with B and N impurities are studied by density functional theory. We find that the most stable sites for the B and N dopants are different. The substitutional B tends to stay in the middle region of a nanodiamond, while the energetically preferable site for N is on the surface of the nanodiamond. The chemical bonding and electronic properties of the B- and N-doped nanodiamonds are also discussed.

In this paper, we present our study of optical properties of ZnS and ZnS:Mn at 0–12 at. % concentration Mn²⁺ prepared by the wet chemical method. All the resulting ZnS samples are of the single phase with sphalerite crystal structure. The average particle size is about 5–10 nm. The photoluminescence intensity of samples is shown to increase with increasing Mn concentration, reaching a maximum at the solid solubility limit of Mn²⁺ in ZnS.

Theoretical investigation of nonlinear frequency conversion in pure ZnO, ZnO:Ag (1.6 at.%) and ZnO:Cu (4.7 at.%) films account for phase effects has been carried out. For this, the constant-intensity approximation of fundamental radiation is applied. The analytical method also lets estimation of the influence of impurities on the nonlinear optical properties of films by third harmonic generation (THG) method and approximation of the maximum value of the third harmonic intensity in pure and doped ZnO by silver and copper films. In this study, the factors which limit the efficiency of the process of conversion of frequency are outlined. Namely, at chosen pump intensity of laser-radiator, it is possible to calculate the coherent length of a crystal-converter. Method of analysis of THG in pure and doped ZnO films, used in the present work, will be extended to other doped nanostructures in future.

Silver molybdate nanoparticles were successfully prepared by the hydrothermal process. Polyaniline–silver molybdate nanocomposites were prepared by in situ chemical oxidative polymerization technique. Silver molybdate nanoparticles and the polymer samples were characterized by conductivity studies, Fourier transform infrared spectra (FT-IR), UV-visible spectra, photoluminescence spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The electrical conductivity of PANI-Cl^- increases when doped with silver molybdate nanoparticles and follows the percolation threshold.

Doping carbon materials with heteroatoms such as N, F is an effective approach to elevating the capacitive performance of supercapacitors. In this paper, nitrogen and fluorine dual-doped two-dimensional (2D) porous carbon nanosheets (PCNSs) have been fabricated by a straightforward template carbonization method, using trisodium citrate as carbon source and self-template, and ammonium fluoride as N/F dopants. The N/F-doped carbon samples are well characterized by a series of techniques and measured in a three-electrode system and two-electrode system, respectively. As a result, N/F-doped carbon has delivered large capacitance of 110Fg${}^{-1}$ at 1Ag${}^{-1}$ and high-energy density of 3.82W h kg${}^{-1}$ at the power density of 0.5kWkg${}^{-1}$. It is also revealed that semi-ionic C–F bonds in PCNSs have enhanced electrical conductivity, hence, facilitating electron transport in the electrode. For comparison, ammonium chloride is used as sole dopant for producing N-doped carbon materials, whose capacitive performances are much lower than the N/F-codoped one, indicating the synergistic effect of N/F for capacitive improvement.

Nickel-rich LiNi${}_{0.8}$Co${}_{0.1}$Mn${}_{0.1}$O₂ (NCM811) oxide is a prospective cathode material of Li-ion batteries owing to its high energy density and affordable price, however, it suffers from the poor cycling performance. The doping for metal cations is considered as an effective way to enhance its cycling stability. In this work, titanium was chosen to partially substitute transition-metal ions, i.e. Ni, Co and Mn, and the Ti content was optimized to improve the electrochemical performance of NCM811. The Ti-doped Li(Ni${}_{0.8}$Co${}_{0.1}$Mn${}_{0.1}{){}_{1-x}}_{}$Ti${}_x$O₂ powder was prepared using high temperature solid-state synthesis. The layered $\alpha$-NaFeO₂-type structure of NCM811 survives in the doped samples, and the lattice parameters $a$ and $c$ increase linearly with the Ti content. XPS spectra indicate that the Ni ions show a mixing state of +2 and +3, and the portion of Ni${}^{2+}$ increases by the Ti doping. The cycling stability is improved evidently by a small amount of Ti doping, i.e. capacity retention of 88.3–96.9% for $x$ = 0.01–0.03 versus 64.1% for $x$ = 0 after 100 cycles at 0.1 C. Thus, the sample with $x$ = 0.01 delivers the high discharge capacity of 180.6 mAh g${}^{-1}$ after 100 cycles, much greater than 116.5 mAh g${}^{-1}$ of $x$ = 0. Nevertheless, more Ti doping with $x$ = 0.04–0.05 deteriorates the electrochemical performance. It illustrates the presence of optimal Ti-doping range in NCM811, which was rationalized as the synergetic effects of bond strength, Li${}^{+}$ diffusion, chemical composition and valence state of cations.

(Ba_0.3Bi_0.7)(Mg_0.05Fe_0.6Ti_0.35)O₃ ceramics were either doped with vanadium or sintered in calcined powder with the same composition. Compared to an undoped ceramic sintered without the calcined powder, both ceramics showed reduced leakage current densities (lower than 1 × 10^-7 A/cm²) and absence of dielectric relaxation behaviors observed in frequency- and temperature-dependent dielectric measurements. The Curie temperatures of both samples were higher than 460°C. The maximum field-induced strain over the applied field, S_max/E_max, of 366 pm/V of the undoped ceramic sintered without the calcined powder increased to 455 and 799 pm/V for the V-doped ceramics and the ceramics sintered with the calcined powder, respectively. The increase was related to a reduced concentration of bismuth vacancy–oxygen vacancy defect dipoles.

Antimony sulfoiodide (SbSI) is a highly efficient energy conversion piezoelectric material. We obtained SbSI doped with tin (II) ions according to the formula Sb${}_{1-x}$Sn_xSI${}_{1-x}$ ($x=0.01$–0.1). This heterovalent doping has been performed by the novel method of synthesis in an aqueous solution. The introduction of tin cations leads to a material Curie point increase of more than 10K. The samples containing 5mol.% of the dopant possess the best piezoelectric properties: piezomodule $d_{33}\sim 750$pC/N, dielectric constant at a frequency of 1kHz — 1758, dielectric loss tangent — 0.054, and piezosensitivity — 50mV×m/N. Thus, tin-doped SbSI is a promising material for highly efficient electromechanical transducers and sensors.

A new series of chiral two-arm dopant containg active group were first synthesized. Four precursors of C1~C4 were obtained at first and then were esterized separately with isosorbide and got four two-arm liquid crystals (MC1~MC4). The chemical structures and LC properties of the liquid crystalline molecule were measured by spectrum and thermal analysis techniques. XRD curves of MC1~MC4 samples only showed broad peaks at wide-angle, no sharp peak was seen for all the samples. The results showed that MC1~MC4 appeared cholesteric phase with oily streak texture or lined texture and finger print texture. Cholesteric phase was successfully induced by isosorbide. The different active group of two arm liquid crystal and chiral core had effects on their liquid crystalline properties.

The paper mainly discussed the preparation of conductive polypyrrole conducting fabrics which were treated with NaOH solution and prepared by in-situ polymerization. It is the first time trying to use PPy coating fabrics for electrical stimulation therapy for diabetic foot cure. FTIR spectroscopy analysis was used to investigate the existence of polypyrrole. The influence of alkali treatment on the conductive property was analyzed. The results showed that after in-situ polymerization, the surface of cotton and PET fabrics became to be black. Alkali treatment period has significant influence on surface resistance of PPy/cotton and PPy/PET fabrics. SEM showed that cells were adhered on the PET multifilament and cells could survival well with the PET/PPy materials.

Highly resistive Al₂O₃ ceramics have been widely used for electrostatic chucking of silicon wafer. However, there are some restrictions to use such chuck material on higher resistance substrates, such as glass or sapphire wafer. In this study, Al₂O₃ compositions were modified by various dopants ; TiO₂, CuO and SiO₂, and their sinterability, crystal structure, electrical properties and chucking property were investigated with different doping concentrations and sintering conditions. Both of TiO₂ and CuO were found to be key dopants on controlling the sintering temperature and electrical resistivity. When 2~3 mol% of TiO₂ and CuO, and 1mol% of SiO₂ were added simultaneously, the specimens having lowered resistivity, ~10¹² Ωcm were obtained at a relatively lowered sintering temperature, 1250°C, which means that the electrostatic chuck for display and LED sapphire chip processes can be economically fabricated by using simple ceramic process.