Non-destructive evaluation of defects in ferromagnetic plates using a sensitive magnetic sensor based on second harmonic response of superconducting Bi1.6Pb0.4Sr2Ca2Cu3O10+�? pellet

[摘要] The characteristics of a magnetic sensor, based on the non-linear electromagnetic response of the weak links present in polycrystalline BPSCCO superconductor are reported. The second harmonic response of the sensor in an alternating magnetic field at 40 kHz and at 77 K being a strong linear function of low d.c. field is utilized for magnetic field sensing. The noise limited resolution of the sensor is found to be 3.16 Ã�? 10^-9 T/√ Hz for 𝐻_a.c. = 16 G and frequency 40 kHz. The magnetic sensor has been applied for non-destructive detection of various types of flaws in ferromagnetic plates and also for detection of small magnetic inclusions in a non-magnetic matrix. Our results suggest that the 2ð‘�?? response based BPSCCO superconductive magnetometer has potential for its appication in the area of non-destructive evaluation of defects in ferromagnetic materials.

[学科分类] 材料工程

[关键词] BPSCCO superconductor;second harmonic response;magnetic sensor;non-destructive evaluation.