Gd-Co alloy films were synthesized by potentiostatic electrolysis on Cu substrates in urea-acetamide-NaBr-KBr melt at 353 K. The electroreduction of Co^2＋ and Gd^3＋ was investigated by cyclic voltammetry. The reduct...Gd-Co alloy films were synthesized by potentiostatic electrolysis on Cu substrates in urea-acetamide-NaBr-KBr melt at 353 K. The electroreduction of Co^2＋ and Gd^3＋ was investigated by cyclic voltammetry. The reduction of Co^2＋ is an irreversible process. Gd^3＋ cannot be reduced alone, but it can be inductively co-deposited with Co^2＋. Both the Gd content and microstructure of the prepared Gd-Co alloy films can be controlled by the deposited potential. The content of Gd was analyzed using an inductively coupled plasma emission spectrometer （ICPES）, and the microstructure was observed by scanning electron micrograph （SEM）. The films were crystallized by heat-treatment at 823 K for 30 s in Ar atmosphere, and then were investigated by XRD. The hysteresis loops of the Gd-Co alloy films were measured by a vibrating sample magnetometer （VSM）. The experimental results reveal that the deposited Gd-Co alloy films are amorphous, while the annealing causes the samples to change from amorphous to polycrystalline, thus enhancing their magnetocrystalline anisotropy and coercivity. Moreover, the magnetic properties of the Gd-Co alloy films depend strongly on the Gd content.展开更多
The Gd-Co-Mn alloys with compositions of Gd33.3Co66.7, Gd33.3Mn66.7, Gd22.2Co74.8Mn3 and Gd25Co70Mn5 were prepared and examined by X-ray diffractometer. The electrochemical properties of these alloys such as discharge...The Gd-Co-Mn alloys with compositions of Gd33.3Co66.7, Gd33.3Mn66.7, Gd22.2Co74.8Mn3 and Gd25Co70Mn5 were prepared and examined by X-ray diffractometer. The electrochemical properties of these alloys such as discharge capacity, cycling performance and high rate dischargeability were investigated by battery testing instruments in alkaline electrolyte. The discharge capacity of Gd22.2Co74.8Mn3 was the highest among these alloys at the same discharge current density, and the maximum value was 376.7 mAh/g discharged at 150 mA/g. The discharge capacities of the alloys Gd33.3Co66.7 and Gd33.3Mn66.7 reached their maxima （about 225 and 325 mAh/g） at discharge current density of 150 mA/g. A comparison of the electrochemical performance of the Gd-Co-Mn alloys revealed that the alloy Gd22.2Co74.sMn3 possessed better electrochemical performance and had better discharge capacity, cycle stability, while the alloy Gd25Co70Mn5 had a better high rate discharge ability. In general, the electrochemical performance of ternary alloys was better than binary alloys in this case.展开更多
基金financially supported by the Science Foundation of the Educational Department of Fujian Prov-ince (No. 2008F5021)the Natural Science Foundation of Fujian Province (No. A0510013)the National Natural Science Foundation of China (No. 60676055)
文摘Gd-Co alloy films were synthesized by potentiostatic electrolysis on Cu substrates in urea-acetamide-NaBr-KBr melt at 353 K. The electroreduction of Co^2＋ and Gd^3＋ was investigated by cyclic voltammetry. The reduction of Co^2＋ is an irreversible process. Gd^3＋ cannot be reduced alone, but it can be inductively co-deposited with Co^2＋. Both the Gd content and microstructure of the prepared Gd-Co alloy films can be controlled by the deposited potential. The content of Gd was analyzed using an inductively coupled plasma emission spectrometer （ICPES）, and the microstructure was observed by scanning electron micrograph （SEM）. The films were crystallized by heat-treatment at 823 K for 30 s in Ar atmosphere, and then were investigated by XRD. The hysteresis loops of the Gd-Co alloy films were measured by a vibrating sample magnetometer （VSM）. The experimental results reveal that the deposited Gd-Co alloy films are amorphous, while the annealing causes the samples to change from amorphous to polycrystalline, thus enhancing their magnetocrystalline anisotropy and coercivity. Moreover, the magnetic properties of the Gd-Co alloy films depend strongly on the Gd content.
基金National Natural Science Foundation of China(50861005,50961002)Natural Science Foundation of Guangxi(2011GXNSFD018005)Plan of the Top Innovation Team Construction of Guangxi University(31)
文摘The Gd-Co-Mn alloys with compositions of Gd33.3Co66.7, Gd33.3Mn66.7, Gd22.2Co74.8Mn3 and Gd25Co70Mn5 were prepared and examined by X-ray diffractometer. The electrochemical properties of these alloys such as discharge capacity, cycling performance and high rate dischargeability were investigated by battery testing instruments in alkaline electrolyte. The discharge capacity of Gd22.2Co74.8Mn3 was the highest among these alloys at the same discharge current density, and the maximum value was 376.7 mAh/g discharged at 150 mA/g. The discharge capacities of the alloys Gd33.3Co66.7 and Gd33.3Mn66.7 reached their maxima （about 225 and 325 mAh/g） at discharge current density of 150 mA/g. A comparison of the electrochemical performance of the Gd-Co-Mn alloys revealed that the alloy Gd22.2Co74.sMn3 possessed better electrochemical performance and had better discharge capacity, cycle stability, while the alloy Gd25Co70Mn5 had a better high rate discharge ability. In general, the electrochemical performance of ternary alloys was better than binary alloys in this case.
