醇体系中合成CuGaS2纳米晶及其形貌演变

Using ethylene glycol as solvent and reductant, CuCl2·2H2O, (NH2)2CS and self-prepared GaCl3 as the starting materials, CuGaS2 nanostrucutures were synthesized on a large scale at 220 ℃. Powder X-ray diffraction,transmission electron microscopy, field-emission scanning electron microscope, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy were used to characterize the products. It demonstrated the evolution of the CuGaS2 particles from spherical assemblies to flowerlike morphology, over time,at 220 ℃. Simultaneously, we elucidated the specific roles of reaction temperature, reaction time and solvent in the formation of the final CuGaS2 nanostructures. A possible formation mechanism of CuGaS2 nanostrucutures was also discussed. The room temperature photoluminescence spectrum showed blue-shift and an increase of intensity, with a decrease in the sizes of CuGaS2 particles.     

A STUDY OF RAMAN SCATTERING AND INFRARED ABSORPTION SPECTRUM IN A NEW SERIES OF MERCURY-BASED HIGH-Tc SUPERCONDUCTOR (Hg,Mo)Sr2(Y1-xCax)Cu2O6+δ

Lattice vibrations of the (Hg,Mo)Sr₂(Y_1-xCa_x)Cu₂O_6+δ—a new series of mercury-based high-T_c superconductor are analyzed with the aid ofgroup theory. The vibrations of species are given. They are 4A_1g+ B_1g+ 5E_g+ 7A_2u + B_2u+ 8E_u. The 4A_1g, B_1g and 5E_g modes are Ramma active, the 6A_2u and 7E_u are infrared active. Phonon vibration characteristics of the samples are studied using Raman scattering and infrared absorption spectra. The experimental results show that the typical phonon vibrational modes appear mainly at 145, 320, 440, 578, 592 and 645cm^-1, The intensities of the 145, 320, 440, 578 and 645 peaks decrease with increasing Ca content x and the position of 645 peak moves to higher wavenumber slightly. In this article, the phonan modes are assigned and their variation behavior with increasing Ca content x are discussed.     

Synthesis and Properties of Pr1-xRbxMnO3 (0.05≤x≤0.08) with Perovskite-Type Structure

Rb-substitued Pr_1-xRb_xMnO₃ (0.05≤x≤0.08) was successfully synthesized by solid state reaction. Powder X-ray diffraction showed that all the compounds were orthorhombic with the space group of Pnma. Spin glass behaviors were observed for all the compounds at low temperature, suggesting the competition between ferromagnetic and antiferromagnetic. The temperature dependence of the resistivity for the compound Pr_0.92Rb_0.08MnO_3.02 at 0 and 2 T magnetic field was also investigated. The compound shows semiconducting behavior, and the band gap is 0.3 eV. The maximum magnetoresistance is about 30% at 2 T magnetic field near 116 K.     

过渡金属氧化物插层化学及其电催化应用的新进展（英文）

插层化学是指客体插入到主体形成插层化合物的过程.近年来,插层化学作为一种有效的材料结构修饰方法,已广泛应用于电化学储能和转换领域.过渡金属氧化物由于其结构和成分的可调性,在插层性能和应用方面取得了很大进展,但仍存在插层机理及性质变化原因不明确等问题.本文首先对过渡金属氧化物的插层机理进行了综合评述,分析归纳了常见的插层制备方法，然后总结了插层过渡金属氧化物在电催化中研究的最新进展,最后对该领域未来面临的机遇和挑战进行了展望.