在二甲亚砜中La-Fe合金膜电化学制备的研究  

Electrochemical Preparation of La-Fe Alloy Films in Dimethylsulfoxide

作　　者：袁定胜[1] 刘冠昆[1] 童叶翔[1] 沙励嫦[1] 

机构地区：[1]中山大学化学与化学工程学院,广东广州510275

出　　处：《中国稀土学报》2001年第3期238-242,共5页Journal of the Chinese Society of Rare Earths

基　　金：广东省自然科学基金资助项目 !(960 0 0 2 )

摘　　要：研究了二甲亚砜 (DMSO)中La3+ 和Fe2 + 在Pt ,Cu和Ni电极上的电化学行为。Fe2 + 在Pt电极上一步不可逆还原为Fe ,La3+ 在Pt电极上表现为准可逆电极过程。在 2 98K时 ,利用循环伏安法测定了 0 0 1mol·L- 1 FeCl2 0 1mol·L- 1 LiCl DMSO溶液中Fe2 + 的扩散系数、传递系数分别为 2 5 4× 10 - 6 cm2 ·s- 1 和 0 2 4;利用计时电流法测定了 0 0 1mol·L- 1 LaCl3 0 1mol·L- 1 LiCl DMSO溶液中La3+ 的扩散系数为 3 10×10 - 6 cm2 ·s- 1 。在铜电极上于 -1 75 0～ -2 45 0V (vs .SCE)下恒电位电解 ,可获得La含量达 2 2 7%～ 3 7 1%的La Fe合金膜 ;应用脉冲电解技术于 2～ 6mA·cm- 2 也可获得La Fe合金膜。这些合金膜是均匀的 。The cyclic voltmmetry and potential step methods were used to investigate the electrochemical behavior of Fe 2+ and La 3+ in FeCl 2 LiCl DMSO and LaCl 3 LiCl DMSO systems on Pt, Cu and Ni cathodes. The electroreduction of Fe 2+ to Fe is irreversible in one step, while the electroreduction of La 3+ to La is quasireversible. The diffusion coefficient of La 3+ in LaCl 3 LiCl DMSO system at 298 K is 3 10×10 6 cm 2·s -1 . The diffusion coefficient and transfer coefficient of Fe 2+ in FeCl 2 LiCl DMSO system at 298 K are 2 54×10 6 cm 2·s -1 and 0 24, respectively. Potentiostatic and pulse electrolysis were used to prepare La Fe alloy films. La Fe alloy films containing La from 22 7% to 37 1% (mass fraction) were prepared by potentiostatic electrolysis on Cu substrates at deposition potential from -1 750 V to -2 450 V (vs SCE). The fine La Fe alloy films were also obtained by pulse electrolysis at pulse current from 2 to 6 mA·cm -2 . The surfaces of these alloy films are smooth, adhesive, uniform and with metallic luster.

关 键 词：稀土 镧 电沉积 DMSO La-Fe合金 扩散系数 传递系数 合金膜 镧铁合金 磁性材料 

分 类 号：TG146.45[一般工业技术—材料科学与工程] TM27[金属学及工艺—金属材料]