非晶Fe_(52)Co_(34)Hf_7B_6Cu_1在中频磁脉冲处理下的正电子湮没研究  

Study on the positron annihilation of amorphous Fe_(52)Co_(34)Hf_7B_6Cu_1 by medium-frequency magnetic pulse treatment

作　　者：金莹[1,2] 晁月盛[2] 张艳华[1] 王莉[1] 

机构地区：[1]辽宁石油化工大学理学院,辽宁抚顺113001 [2]东北大学理学院,沈阳110004

出　　处：《功能材料》2014年第10期102-104,108,共4页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(50771025)

摘　　要：对Fe52Co34Hf7B6Cu1非晶试样进行了中频磁脉冲处理,脉冲磁场频率、作用时间保持恒定:1 500Hz、10min,脉冲磁场强度分别为15.92,19.9和23.88kA/m。用穆斯堡尔谱(MS)和正电子湮没寿命谱(PAS)方法研究了该试样在中频磁脉冲处理前后的结构及结构缺陷变化。结果表明,在非晶合金的制备态,正电子主要在自由体积中湮没,经中频磁脉冲处理后,非晶合金发生不可逆的结构弛豫,导致湮没寿命τ1下降。随着脉冲磁场强度的增加,非晶合金发生晶化,产生新的正电子俘获中心,导致强度I2急剧增加,I1急剧降低。The amorphous alloy specimens Fe52 Co34 Hf7 B6 Cu1 were treated by medium-frequency magnetic pulse. The treatment conditions were as follows：the pulsing magnetic field frequency and the acting time were kept at 1 500 Hz,10 min,and the field intensity were 15.92,19.9 and 23.88 kA/m respectively.The structural and structural defects of specimens before and after magnetic-pulsing were researched by Mossbauer spectroscopy （MS）and positron annihilation lifetime spectra （PAS）.The results show that in the as-quenched amorphous al-loy,the positron are mainly localized at vacancy-sized free volumes in the amorphous based phase,and the amorphous alloy produced irreversible structural relaxation after being treated by the medium-frequency mag-netic pulse which leaded to the decline of the annihilation lifetimeτ1 .With the increase of pulsing magnetic field intensity,new trapping centers of positrons are produced owing to the crystallization of amorphous phase,that leads to the intensity I 2 increases and I 1 decreases drastically.

关 键 词：Fe52Co34Hf7B6Cu1非晶合金 中频磁脉冲 正电子湮没寿命 结构缺陷 

分 类 号：TG139.8[一般工业技术—材料科学与工程]