钽替代部分锰对锰钴锗合金马氏体相变和磁性能的影响

Effects of Ta substitution of Mn on Martensite transition and magnetic properties of MnCoGe alloy

为研究Ta替代部分Mn对Mn1-xTaxCoGe(x=0,0.01,0.02,0.03,0.04)系列合金晶体结构、马氏体相变和磁性能的影响,将Mn,Ta,Co,Ge金属单质(纯度为99.99%以上)置于充满高纯氩气(纯度为99.99%以上)的WK-Ⅱ型非自耗电弧炉内进行熔炼,冷却后置于充满氩气(纯度为99.99%以上)的石英管中,在1073 K的温度下退火120 h,随炉冷却至室温后得到Mn1-xTaxCoGe(x=0,0.01,0.02,0.03,0.04)系列合金。采用X射线衍射(XRD)、差示扫描量热仪(DSC)和多参数磁学测量系统对合金材料的晶体结构、马氏体相变和磁性能进行了表征。实验结果发现,室温下的Mn1-xTaxCoGe(x=0,0.01,0.02,0.03,0.04)系列合金呈现单一的正交马氏体相结构,Ta取代Mn没有改变合金在室温下的晶体结构,晶胞体积随着Ta含量的升高而增大;随着Ta对Mn的取代,马氏体相变温度从480K升高到585 K;马氏体相居里温度随Ta含量增加而降低,Ta含量从0到0.04的过程中,马氏体相居里温度从337 K降低到325 K。

In order to study the effect of Ta substitution for Mn on the crystal structure,martensitic transformation and magnetic properties of Mn1-xTaxCoGe(x=0,0.01,0.02,0.03,0.04)alloys,Mn,Ta,Co,Ge metal simplex(purity more than 99.99%)were put in a WK-Ⅱtype non-consumable arc furnace for smelting with a high-purity argon gas(purity more than 99.99%),annealed in a quartz tube at a temperature of 1073 K for 120 h,and then cooled to room temperature with the furnace to obtain a Mn1-xTaxCoGe(x=0,0.01,0.02,0.03,0.04)alloys.X-ray diffraction(XRD),differential scanning calorimeter(DSC)and multi-parameter magnetic measurement system were used to characterize the crystal structure,martensitic transformation and magnetic properties of the alloys.The experimental results show that the Mn1-xTaxCoGe(x=0,0.01,0.02,0.03,0.04)alloys at room temperature showed a single orthogonal martensitic phase structure.The substitution of Ta for Mn did not change the crystal structure of the alloys at room temperature.The cell volume increased with increasing Ta content.With the substitution of Ta for Mn,the martensitic transformation temperature increased from 480 K to 585 K.The Curie temperature of the martensitic phase decreased with increasing Ta content.During the Ta content increasing from 0 to 0.04,the Curie temperature of the Martensite phase decreased from 337 K to 325 K.