溶融法和机械合金法制备Fe0．65Cr0．35-xVx合金的穆斯堡尔谱研究

Mssbauer spectrum study on Fe_(0.65)Cr_(0.35-x)V_x alloys prepared by arc-melting and mechanical alloying

通过机械合金法和溶融法制备了Fe_(0.65) Cr_(0.35-x)V_x三元合金,采用X射线衍射、穆斯堡尔谱和振动样品磁强计(VSM)对其三元合金性质进行了研究。两种不同制备方法得到的样品均为体心立方(bcc)结构。采用二项式理论计算了的超精细磁场分布.并与实验值进行比对,在V高浓度时实验与理论值吻合地很好.这表明V原子可随机地占据Fe的bcc晶格位置;而当V原子浓度增加时,超精细磁场分布的实验值转移到低场处。引起它的原因可能有两种:(1)Fe-Cr系统比Fe-V系统进一步合金化更困难;(2) Cr原子或Cr原子团簇形成近程有序。从平均每个Fe原予的磁矩随V含量的变化图中可以看出,随着V含量的增加,平均原子磁矩逐渐减小。

Ternary Fe0.65Cr0.35-xVx alloys prepared by arc-melting and mechanical alloying were studied by X-ray diffraction,Moessbauer spectra and VSM. Both samples prepared by different methods maintain the BCC structure. We calculated theoretical field distributions of the ternary Fe0.65 Cr0.35-xVx alloys using binomial theory. And compared with the experimental ones for these alloys,the good agreement of experimental HFD＇s for the high concentration of vanadium with the calculated HFD＇s indicates that the vanadium atom occupy of the bee lattice sites of Fe randomly. With the inceasing of vanadium concentration,the experimental HFD＇s are considerably shifted to lower fields. It may be caused by two reasons.one is that the alloying progress of Fe-Cr system is more difficult than the one of Fe-V, second is that chromium atoms undergo the short range order（SRO）effect or form cluster. It was found that the average moment per Fe atom decrease versus V concentration increase for Fe0.65 Cr0.35-x Vx alloys.