AI 中文总结
该研究利用EPR谱仪，在不同磁场和温度下表征FeSe单晶，通过非共振信号确定其超导临界参数，观测到Fe²⁺顺磁信号及超导混合态的非线性信号。
AI 中文摘要
使用EPR谱仪，在高达6000 Oe的磁场、3.5 K至8 K的超导态温度，以及8 K以上至25 K的正常态温度下，对单晶FeSe的性质进行了研究。研究表明，通过测量零磁场及高达30 Oe的弱磁场下的非共振谱仪信号，可确定FeSe单晶的临界温度Tc、超导转变宽度，以及第一临界磁场Hc1的值。在1400 Oe和3400 Oe的磁场下观测到共振EPR信号，对应FeSe晶体中 doubly ionized iron atoms（Fe²⁺）的顺磁性。在3.5 K至8 K的温度下，高达6000 Oe的磁场中的非共振EPR信号是磁场的非线性函数，对应FeSe的超导混合态；而在8 K以上（至25 K）的温度下，这些信号与磁场无关。
英文摘要
Using an EPR spectrometer, the properties of single-crystal FeSe were studied in a magnetic field up to 6000 Oe at temperatures from 3.5 K to 8 K in the superconducting state and at temperatures above 8K and up to 25K in the normal state. It was shown that by measuring non-resonant spectrometer signals in zero and weak magnetic fields up to 30 Oe, it is possible to determine critical temperature Tc, the superconducting transition width, and the value of the first critical magnetic field Hc1 in FeSe single-crystal. Resonant EPR signals are observed in fields at 1400 Oe and 3400 Oe, which corresponds to the paramagnetism of doubly ionized iron atoms (Fe2+) in the FeSe crystal. Non-resonant EPR signals in a magnetic field up to 6000 Oe at temperatures from 3.5K to 8K are a nonlinear function of the field, and correspond to the superconducting mixed state of the FeSe, but at temperatures above 8K (up to 25K) they are field independent.
Comments9 pages, 6 figures
