By means of new muon spin relaxation experiments, we disentangle extrinsic and intrinsic sources of low-temperature bulk magnetism in the candidate topological Kondo insulator (TKI)

. Results on Al-flux-grown

single crystals are compared to those on a large floating-zone-grown

single crystal in which a 14 meV bulk spin exciton has been detected by inelastic neutron scattering. Below

, we detect the gradual development of quasistatic magnetism due to rare-earth impurities and Sm vacancies. Our measurements also reveal two additional forms of intrinsic magnetism: (1) underlying low-energy (

) weak magnetic moment (

) fluctuations similar to those detected in the related candidate TKI

that persist down to millikelvin temperatures, and (2) magnetic fluctuations consistent with a 2.6 meV bulk magnetic excitation at zero magnetic field that appears to hinder surface conductivity above

. We discuss potential origins of the magnetism.

通过新的介子自旋弛豫实验，我们可以解开候选拓扑近藤绝缘子（TKI）中低温体磁的外部和本征源

。助焊剂生长的结果

将单晶与在大浮区上生长的单晶进行比较

通过非弹性中子散射检测到14 meV本体自旋激子的单晶体。以下

，我们检测到由于稀土杂质和Sm空位导致的准静态磁场的逐渐发展。我们的测量还揭示了固有磁场的两种其他形式：（1）潜在的低能（

）弱磁矩（

）波动，类似于在相关候选TKI中检测到的波动

会持续下降到毫ikelvin温度，并且（2）磁场波动与2.6 meV在零磁场下的体磁激发相一致，这似乎会阻碍表面电导率高于

。我们讨论了磁性的潜在起源。