Nonlinear uniaxial pressure dependence of the resistivity in Sr1−xBax Fe1.97Ni0.03As2<xref rid="cpb_27_8_087402fn1" ref-type="fn">*</xref><fn id="cpb_27_8_087402fn1"><label>*</label>Project supported by the Science Fonds from the Ministry of Science and Technology of China (Grant Nos. 2017YFA0302903, 017YFA0303103, 2016YFA0300502, and 2015CB921302), the National Natural Science Foundation of China (Grant Nos. 11674406 and 11674372), the “Strategic Priority Research Program (B)” of the Chinese Academy of Sciences (Grant Nos. XDB07020300 and XDB07020200), and the Youth Innovation Promotion Association of the Chinese Academy of Sciences.</fn>

Nonlinear uniaxial pressure dependence of the resistivity in Sr_1−xBa_x Fe_1.97Ni_0.03As₂**

Project supported by the Science Fonds from the Ministry of Science and Technology of China (Grant Nos. 2017YFA0302903, 017YFA0303103, 2016YFA0300502, and 2015CB921302), the National Natural Science Foundation of China (Grant Nos. 11674406 and 11674372), the “Strategic Priority Research Program (B)” of the Chinese Academy of Sciences (Grant Nos. XDB07020300 and XDB07020200), and the Youth Innovation Promotion Association of the Chinese Academy of Sciences.

Mao Hui-Can^{1, 2}, Gong Dong-Liang^{1, 2}, Ma Xiao-Yan^{1, 2}, Luo Hui-Qian¹, Yang Yi-Feng^{1, 2, 3}, Shan Lei^{1, 2, 3}, Li Shi-Liang^{1, 2, 3, †}

(color online) (a) The cubic (black squares) and quadratic (red circles) components in the uniaxial pressure dependence of resistance of the x = 0.64 sample at 135 K. (b) Illustration on how the quadratic term may be wrongly. The blue line is a linear fit to the cubic function of x + x³ (black squares). The red circles are subtracted results from the cubic function by the linear fit result. The cyan line is fitted by the quadratic function. (c) Uniaxial pressure dependence of the nonlinear part of the resistance for the x = 0.64 sample. The solid lines are fitted by Eq. (15). The numbers in the label are temperatures with the unit of Kelvin. (d) Temperature dependence of γ for the x = 0.64 sample. The solid line is fitted by Eq. (16).