He^+辐照对Ga_(0.94)Mn_(0.06)As薄膜铁磁性的改善  

Amending the ferromagnetic properties of Ga_(0.94)Mn_(0.06)As films by He^+ irradiation

作　　者：丁斌峰[1] 相凤华[1] 王立明[1] 王洪涛[1] 

机构地区：[1]廊坊师范学院物理与电子信息学院,廊坊065000

出　　处：《物理学报》2012年第4期326-331,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50802041;50872050);国家重点基础研究发展计划(973)项目(批准号:2011CB832923);廊坊师范学院重点项目(批准号:LSZZ201 101)资助的课题;Project supported by the National Natural Science Foundation of China(Grant Nos.10875004;11005005);the National Basic Research Program of China(Grant No.2010CB832904)

摘　　要：离子辐照半导体可以很好的改善半导体材料的磁学性质.用He^+辐照Ga_(0.94)Mn_(0.06)As薄膜,可以较方便的调制Ga_(0.94)Mn_(0.06)As薄膜中产生铁磁性载体的浓度.由于空穴居间而导致Ga_(0.94)Mn_(0.06)As薄膜的铁磁性,可以通过He^+的辐照来得到改善,其结果是Ga_(0.94)Mn_(0.06)As薄膜的矫顽力可以增加3倍多.当He^+辐照流强增加时,居里温度和沿着样品面外磁化难轴方向的饱和磁场都减小了.被辐照的Ga_(0.94)Mn_(0.06)As薄膜的电学性质和结构特征显示,He^+辐照Ga_(0.94)Mn_(0.06)As薄膜可以有控制地改善它的铁磁性,其结果源于He^+辐照Ga_(0.94)Mn_(0.06)As薄膜所诱导产生电缺陷对空穴的补偿,而不是He^+辐照改变了Ga_(0.94)Mn_(0.06)As薄膜的结构.Ion irradiation of semiconductors is a well understood method to tune the carrier concentration in a controlled manner.We show that the ferromagnetism in Ga_（0.94）Mn_（0.06）As films,known to be hole-mediated,can be modified by He ion irradiation.The coercivity can be increased by more than three times.The magnetization,Curie temperature and the saturation field along the out-of-plane hard axis all decrease as the fluence increases.The electrical and structural characterization of the irradiated Ga_（0.94）Mn_（0.06）As layers indicates that the controlled amending of magnetism results from a compensation of holes by generated electrical defects and not from a structural modification.

关 键 词：离子辐照 铁磁性 磁阻 

分 类 号：O484.43[理学—固体物理]