Cho Kyuil, Kończykowski Marcin, Tanatar Makariy A, Mazin Igor I, Liu Yong, Lograsso Thomas A, Prozorov Ruslan
Ames National Laboratory, Ames, IA 50011, USA.
Department of Physics, Hope College, Holland, MI 49423, USA.
Materials (Basel). 2023 Jun 22;16(13):4520. doi: 10.3390/ma16134520.
Low-temperature variable-energy electron irradiation was used to induce non-magnetic disorder in a single crystal of a hole-doped iron-based superconductor, Ba1-xKxFe2As2, = 0.80. To avoid systematic errors, the beam energy was adjusted non-consequently for five values between 1.0 and 2.5 MeV when sample resistance was measured in situ at 22 K. For all energies, the resistivity raises linearly with the irradiation fluence suggesting the creation of uncorrelated dilute point-like disorder (confirmed by simulations). The rate of the resistivity increase peaks at energies below 1.5 MeV. Comparison with calculated partial cross-sections points to the predominant creation of defects in the iron sublattice. Simultaneously, superconducting Tc, measured separately between the irradiation runs, is monotonically suppressed as expected, since it depends on the total scattering rate, hence on the total cross-section, which is a monotonically increasing function of the energy. Our work experimentally confirms an often-made assumption of the dominant role of the iron sub-lattice in iron-based superconductors.
利用低温可变能量电子辐照在空穴掺杂的铁基超导体Ba1-xKxFe2As2（x = 0.80）单晶中诱导非磁性无序。为避免系统误差，当在22 K原位测量样品电阻时，对1.0至2.5 MeV之间的五个值非连续地调整束流能量。对于所有能量，电阻率随辐照通量呈线性增加，这表明产生了不相关的稀有点状无序（模拟结果证实）。电阻率增加率在能量低于1.5 MeV时达到峰值。与计算的部分截面比较表明，铁亚晶格中主要产生缺陷。同时，在辐照运行之间单独测量的超导转变温度Tc如预期的那样被单调抑制，因为它取决于总散射率，因此取决于总截面，而总截面是能量的单调递增函数。我们的工作通过实验证实了一个经常做出的假设，即铁亚晶格在铁基超导体中起主导作用。
