Zn2＋ ions doped quasi-one-dimensional spin-chain materials LiCul-xZnxVO4（x=0, 0.1, 0.2） were prepared by solid-state reaction and the effect of nonmagnetic Zn2＋ ions on the crystal structure, valence state and mag...Zn2＋ ions doped quasi-one-dimensional spin-chain materials LiCul-xZnxVO4（x=0, 0.1, 0.2） were prepared by solid-state reaction and the effect of nonmagnetic Zn2＋ ions on the crystal structure, valence state and magnetic proper- ties of them were studied by X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS） and dc magnetization. The elongation of a and b axes and the shrinkage of c axis indicate a reduced effect of the Jahn-Teller distortion after Zn2＋ ions doping, while the valence state of transition metal ions in LiCu1- xZnrVO4 remains unchanged since the equi- valence doping of Zn2＋ ions on the Cu2＋ sites. The corrected Bonner-Fisher equation fitting to the susceptibility indicates that isolated dimers and spins are created along with the departure from infinite spin chains to finite ones.展开更多
The effect of external quasi-hydrostatic pressure on the inverse spinel structure of LiCuVO4 was studied in this paper. High-pressure synchrotron X-ray diffraction and Raman spectroscopy measurements were carried out ...The effect of external quasi-hydrostatic pressure on the inverse spinel structure of LiCuVO4 was studied in this paper. High-pressure synchrotron X-ray diffraction and Raman spectroscopy measurements were carried out at room temperature up to 35.7 and 40.3 GPa, respectively. At a pressure of about 20 GPa, both Raman spectra and X-ray diffraction results indicate that LiCuVO4 was transformed into a monoclinic phase, which remained stable up to at least 35.7 GPa. Upon release of pressure, the high-pressure phase returned to the initial phase. The pressure dependence of the volume of low pressure orthorhombic phase and high-pressure monoclinic phase were described by a second-order Birch-Murnaghan equation of state, which yielded bulk modulus values of B0 = 197 （5） and 232（8） GPa, respectively. The results support the empirical suggestion that the oxide spinels have similar bulk modulus around 200 GPa.展开更多
以碳酸锂、五氧化二钒和硝酸铜为原料,通过球磨混合结合高温固相法成功制备锂离子电池新型负极材料LiCuVO_4。热重分析法（TG）、X射线衍射光谱法（XRD）、扫描电子显微镜法（SEM）和电化学测试方法对合成材料进行了研究。结果表明所制...以碳酸锂、五氧化二钒和硝酸铜为原料,通过球磨混合结合高温固相法成功制备锂离子电池新型负极材料LiCuVO_4。热重分析法（TG）、X射线衍射光谱法（XRD）、扫描电子显微镜法（SEM）和电化学测试方法对合成材料进行了研究。结果表明所制备LiCuVO_4负极材料主要由微米尺寸的块状颗粒组成。在0.01~3.0 V充放电区间内,在50 m A/g进行充放电,所制备的材料首次充电比容量达到425.2 m Ah/g,循环50次后充电比容量仍保持在370.8 m Ah/g。在1 A/g电流密度下,循环50次后,充电比容量仍高达288.6 m Ah/g。展开更多
文摘Zn2＋ ions doped quasi-one-dimensional spin-chain materials LiCul-xZnxVO4（x=0, 0.1, 0.2） were prepared by solid-state reaction and the effect of nonmagnetic Zn2＋ ions on the crystal structure, valence state and magnetic proper- ties of them were studied by X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS） and dc magnetization. The elongation of a and b axes and the shrinkage of c axis indicate a reduced effect of the Jahn-Teller distortion after Zn2＋ ions doping, while the valence state of transition metal ions in LiCu1- xZnrVO4 remains unchanged since the equi- valence doping of Zn2＋ ions on the Cu2＋ sites. The corrected Bonner-Fisher equation fitting to the susceptibility indicates that isolated dimers and spins are created along with the departure from infinite spin chains to finite ones.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11074089 and 11004073)the National Basic Research Program of China (Grant No. 2011CB808200)CHESS is supported by NSF and NIH/NIGMS through a NSF award DMR-0936384
文摘The effect of external quasi-hydrostatic pressure on the inverse spinel structure of LiCuVO4 was studied in this paper. High-pressure synchrotron X-ray diffraction and Raman spectroscopy measurements were carried out at room temperature up to 35.7 and 40.3 GPa, respectively. At a pressure of about 20 GPa, both Raman spectra and X-ray diffraction results indicate that LiCuVO4 was transformed into a monoclinic phase, which remained stable up to at least 35.7 GPa. Upon release of pressure, the high-pressure phase returned to the initial phase. The pressure dependence of the volume of low pressure orthorhombic phase and high-pressure monoclinic phase were described by a second-order Birch-Murnaghan equation of state, which yielded bulk modulus values of B0 = 197 （5） and 232（8） GPa, respectively. The results support the empirical suggestion that the oxide spinels have similar bulk modulus around 200 GPa.
文摘以碳酸锂、五氧化二钒和硝酸铜为原料,通过球磨混合结合高温固相法成功制备锂离子电池新型负极材料LiCuVO_4。热重分析法（TG）、X射线衍射光谱法（XRD）、扫描电子显微镜法（SEM）和电化学测试方法对合成材料进行了研究。结果表明所制备LiCuVO_4负极材料主要由微米尺寸的块状颗粒组成。在0.01~3.0 V充放电区间内,在50 m A/g进行充放电,所制备的材料首次充电比容量达到425.2 m Ah/g,循环50次后充电比容量仍保持在370.8 m Ah/g。在1 A/g电流密度下,循环50次后,充电比容量仍高达288.6 m Ah/g。
