In掺杂对磁性半导体Li_(1.05)(Zn_(0.925),Mn_(0.075))As中铁磁序的调控  

Manipulation of ferromagnetic ordering in magnetic semiconductor Li1.05(Zn0.925,Mn0.075)As by In doping

作　　者：谢玲凤 董金瓯 赵雪芹 杨巧林 宁凡龙 Xie Ling-Feng;Dong Jin-Ou;Zhao Xue-Qin;Yang Qiao-Lin;Ning Fan-Long(Zhejiang Province Key Laboratory of Quantum Technology and Device,School of Physics,Zhejiang University,Hangzhou 310058,China;Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China;State Key Laboratory of Silicon and Advanced Semiconductor Materials,Zhejiang University,Hangzhou 310058,China;Science and Technology Innovation Center,Chifeng High-Tech Industrial Development Zone,Chifeng 025250,China)

机构地区：[1]浙江大学物理学院,浙江省量子技术与器件重点实验室,杭州310058 [2]南京大学,人工微结构科学与技术协同创新中心,南京210093 [3]浙江大学,硅及先进半导体材料全国重点实验室,杭州310058 [4]赤峰高新技术产业开发区,科技创新中心,赤峰025250

出　　处：《物理学报》2024年第8期317-322,共6页Acta Physica Sinica

基　　金：国家重点研究发展计划(批准号:2022YFA1402701,2022YFA1403202);国家自然科学基金(批准号:12074333);浙江省重点研发计划(批准号:2021C01002)资助的课题.

摘　　要：磁性半导体中磁矩受载流子调控形成有序态,但其机制尚存在着争议.本文利用高温固相反应法,通过(Zn^(2+),In^(3+))替换,即In^(3+)占据Zn^(2+)的晶格位置,在p型块状磁性半导体Li_(1.05)(Zn_(0.925),Mn_(0.075))As中引入n型载流子,成功合成了一系列Li_(1.05)(Zn_(0.925-y),Mn_(0.075),In_(y))As(y=0,0.05,0.075,0.1)新材料.在保持Mn掺杂浓度为7.5%不变时,仍可在所有In掺杂的样品中观察到铁磁转变.随着In掺杂浓度的增大,其居里温度被不断压制.样品的电阻率随着In掺杂浓度的增大而逐渐增大.实验结果表明,随着In的掺杂,Li_(1.05)(Zn_(0.925),Mn_(0.075)),As中原有的p型载流子被部分抵消,导致总载流子浓度降低,反映了n型载流子对Li_(1.05)(Zn_(0.925),Mn_(0.075))As中铁磁序的压制作用,同时也验证了载流子对磁性半导体中铁磁序的重要影响.Magnetic semiconductors(MSs)that can manipulate both spin degree of freedom and charge degree of freedom have become an important research field in semiconductor spintronics.In recent years,a new series of bulk form MSs,which are iso-structure to the iron-based superconductors were reported.In these new materials,spins and carriers are separately introduced,and can be precisely manipulated.Li(Zn,Mn)As with T_(C)~50 K is the first bulk MS with spins and charges separated.The Li(Zn,Mn)As has p-type carriers,which is in contradiction with the theoretical calculation results by Masek et al.,who claimed that doping extra Li will induce n-type carriers.So,it is necessary to study the formation reason of hole carriers in Li(Zn,Mn)As and their effect on ferromagnetic ordering.In this work,a series of Li_(1.05)(Zn_(0.925-y),Mn_(0.075),In_(y))As(y=0,0.05,0.075,0.1)new materials are successfully synthesized by introducing n-type carriers into the p-type bulk MS Li_(1.05)(Zn_(0.925),Mn_(0.075))As through(Zn^(2+),In^(3+))substitution.Magnetization measurements reveal that all the samples still maintain a ferromagnetic transition signal similar to MS Li_(1.05)(Zn_(0.925),Mn_(0.075))As,and the Curie temperature TC is obviously suppressed with the increase of In-doping concentration.Clear hysteresis loops demonstrate the ferromagnetic ordering state.The resistivity increases gradually with the increase of In-doping concentration.Our results show that the(Zn^(2+),In^(3+))substitution successfully introduces n-type carriers into Li_(1.05)(Zn_(0.925),Mn_(0.075))As,and the original p-type carriers in Li_(1.05)(Zn_(0.925),Mn_(0.075))As,which are partial neutralized,resulting in the decrease of p-type carrier concentrations,which obviously suppresses the ferromagnetic ordering of Li(Zn,Mn)As.It reflects the important roles played by carriers in forming ferromagnetic ordering in MS materials.The fabrication of Li_(1.05)(Zn_(0.925-y),Mn_(0.075),In_(y))As material gives us a better understanding of the mechanism of ferromagnetic ordering

关 键 词：磁性半导体 居里温度 铁磁序 

分 类 号：O469[理学—凝聚态物理]