Effect of residual stress on nematic domains in BaFe2-xNixAs2 studied by angular magnetoresistance  

作　　者：胡定 张汶良 魏源 张笑天 任聪 单磊 杨义峰 罗会仟 李世亮 

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China [2]Collaborative Innovation Center of Quantum Matter, Beifing, China

出　　处：《Chinese Physics B》2016年第5期342-345,共4页中国物理B（英文版）

基　　金：Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB07020300);the National Basic Research Program of China(Grant Nos.2012CB821400 and 2011CBA00110);the National Natural Science Foundation of China(Grant Nos.11374011,11374346,and 11305257)

摘　　要：We have studied the angular magnetoresistance of iron pnictides BaFe_（2-x）Ni_xAs_2, which shows clear 180 degree periodicity as fitted by a cosine function. In the x = 0.065 sample, the phase of the two-fold symmetry changes 90 degrees above the tetragonal-to-orthorhombic structural transition temperature Ts. Since the phase at low temperature is associated with the rotation of orthorhombic domains by magnetic field, we show that even vacuum grease can push the presence of orthorhombic domains at temperatures much higher than Ts. Our results suggest that residual stress may have significant effects in studying the nematic orders and its fluctuations in iron pnictides.We have studied the angular magnetoresistance of iron pnictides BaFe_（2-x）Ni_xAs_2, which shows clear 180 degree periodicity as fitted by a cosine function. In the x = 0.065 sample, the phase of the two-fold symmetry changes 90 degrees above the tetragonal-to-orthorhombic structural transition temperature Ts. Since the phase at low temperature is associated with the rotation of orthorhombic domains by magnetic field, we show that even vacuum grease can push the presence of orthorhombic domains at temperatures much higher than Ts. Our results suggest that residual stress may have significant effects in studying the nematic orders and its fluctuations in iron pnictides.

关 键 词：SUPERCONDUCTIVITY electronic nematic fluctuations iron pnictides 

分 类 号：O469[理学—凝聚态物理]