【摘要】 本文讨论了一种脉冲磁场下确定高T_c氧化物上临界场的方法。利用锁相放大器,使测量信噪比提高近二个量级。本文分析了所测量的信号。 确定H_c2为磁阻饱和时的磁场。最后测量了Bi_1.6Pb_0.4Sr₂Ca₂Cu_3.2O_y的H_c2与温度关系。更多还原

【Abstract】 This paper discusses a mothod for determining the upper critical magnetic field of highT_c superconductor under pulsed magnetic field. The precision of measurement was raised nearly by two power magnitude using a lock-in amplifier. We have analyzed the measured signal.The H_c2 is defined as the field where the resistance becomes nnchanged. Finally, the relation of H_c2 with the temperature of Bi_1.6Pb（0.4）Sr₂Ca₂Cu_3.2O_y has been measured更多还原