The testing items include: critical temperature (Tc), measuring the transition temperature range from the normal state to the superconducting state of the material, with an accuracy of 0.01 K; critical magnetic field (Hc), determining the minimum magnetic field strength that destroys the superconducting state, with a resolution of 0.001 T; critical current density (Jc), assessing the maximum current-carrying capacity, with an error range of ≤5%; resistivity testing, measuring resistance values in the 10⁻Ωm range; magnetic susceptibility measurement; thermal analysis testing, determining melting and crystallization temperatures; and microstructure analysis, observing the microstructure of the material.
Regarding testing methods, resistivity testing uses the DC four-probe method; critical current density measurement uses the four-probe method; magnetic susceptibility measurement combines specific low-temperature magnetic performance testing specifications; thermal analysis testing uses differential scanning calorimetry; and microstructure analysis utilizes scanning electron microscopy.
The testing equipment standards require the PPMS integrated physical property measurement system to accurately measure resistivity and magnetic susceptibility within the temperature range of 1.9K-400K; the SQUID magnetometer is equipped with a 7T superconducting magnet, capable of measuring hysteresis loops in magnetic fields from 0 to 7T; the cryostat system provides a continuously variable temperature environment from 4K to 300K; the high-precision DC power supply outputs current ranging from 1μA to 1A with a resolution of 10fA; the X-ray diffractometer is equipped with a LynxEye detector with an angular resolution of 0.0001; the scanning electron microscope has a resolution of 1nm and is equipped with an EDAX energy dispersive spectroscopy system; the four-probe test stage supports low-temperature testing from 77K to 300K; and the vibrating sample magnetometer has a magnetic field range of 3T and a sensitivity of 10⁻⁶emu.
