Low temperature specific heat in BaFe_(1.9)Ni_(0.1)As_2 single crystals  

作　　者：ZENG Bin MU Gang LUO HuiQian WEN HaiHu 

机构地区：[1]National Laboratory for Superconductivity,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2010年第7期1221-1224,共4页中国科学:物理学、力学、天文学(英文版)

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 10221002/A0402 and 10774170/A0402);the National Basic Research Program of China (Grant Nos. 2006CB601000,2006CB921107,and 2006CB921802);the Chinese Academy of Sciences (ITSNEM)

摘　　要：Low-temperature specific heat was measured on the BaFe1.9Ni0.1As2 single crystals with critical transition temperature Tc = 20.1 K.A clear specific heat jump with the value ΔC/T|Tc ≈ 23 mJ/mol K2 was observed.In addition,a roughly linear magnetic field dependence of the electronic specific heat coefficient Δγ(H) was found in the zero-temperature limit,suggesting that at least one Fermi pocket,probably the hole derivative one,was fully gapped with a small anisotropy in the present sample.A slight curvature of the curve Δγ(H) may suggest a complex gap structure(anisotropic gap or nodes) at other Fermi surfaces.Low-temperature specific heat was measured on the BaFe1.9Ni0.1As2 single crystals with critical transition temperature Tc = 20.1 K.A clear specific heat jump with the value ΔC/T|Tc ≈ 23 mJ/mol K2 was observed.In addition,a roughly linear magnetic field dependence of the electronic specific heat coefficient Δγ(H) was found in the zero-temperature limit,suggesting that at least one Fermi pocket,probably the hole derivative one,was fully gapped with a small anisotropy in the present sample.A slight curvature of the curve Δγ(H) may suggest a complex gap structure(anisotropic gap or nodes) at other Fermi surfaces.

关 键 词：specific heat BaFe1.9Ni0.1As2 nodeless gap 

分 类 号：O611.3[理学—无机化学]