Proper characterisation of investigated samples is vital when studying superconductivity as impurities and doping inhomogeneities can affect the physical properties of the measured system. We present a method where a polarised neutron imaging setup utilises the precession of spin-polarised neutrons in the presence of a trapped field in the superconducting sample to spatially map out the critical temperature for the phase transition between superconducting and non-superconducting states. We demonstrate this method on a superconducting crystal of the prototypical high-temperature superconductor (La,Sr)₂CuO₄. The results, which are backed up by complementary magnetic susceptibility measurements, show that the method is able to resolve minor variations in the transition temperature across the length of the LSCO crystal, caused by inhomogeneities in strontium doping.

当研究超导性时，正确表征被研究样品至关重要，因为杂质和掺杂不均匀性会影响被测系统的物理性能。我们提出了一种方法，其中极化中子成像装置在超导样品中存在俘获场的情况下利用自旋极化中子的进动，以空间映射出超导状态和非超导状态之间相变的临界温度。我们在原型高温超导体（La，Sr）₂ CuO ₄的超导晶体上证明了该方法。通过互补磁化率测量得到的结果表明，该方法能够解决由于锶掺杂不均匀而导致的整个LSCO晶体长度上转变温度的微小变化。