Diffusive-like effects and possible non trivial local topology on the half-Heusler YPdBi compound

The non-ambiguous experimental identification of topological states of matter is one of the main interesting problems regarding this new quantum state of matter. In particular, the half-Heusler family RMT (R = rare-earth, T = Pd, Pt or Au and T = Bi, Sb, Pb or Sn) could be a useful platform to explore these states due to their cubic symmetry and the topological properties tunable via their unit cell volume and/or the nuclear charges of the M and T atoms. In this work, we report electron spin resonance (ESR) and complementary macroscopic measurements in the Nd-3 (+) -doped putative topologically trivial semimetal YPdBi. Following the Nd-3 (+) ESR lineshape as a function of microwave power, size of the particle and temperature, we have been able to observe an evolution from a Dysonian lineshape to a diffusive-like lineshape. Furthermore, the Nd-3 (+) ESR intensity saturation is concentration dependent, which could be due to a phonon-bottleneck process. Comparing these results with the Nd-3 (+) -doped YPtBi, we discuss a possible scenario in which the Nd-3 (+) ions could locally tune the topological properties of the system. (c) 2018 Author(s). (AU)