  209Bi nuclear magnetic resonance (NMR) spectroscopy was employed to probe
potential spin-orbit effects on orbital diamagnetism in YPtBi and YPdBi
crystals. The observed opposite sign and temperature dependent magnitude of
209Bi NMR shifts of both crystals reveal experimental signatures of enhanced
orbital diamagnetism induced by spin-orbit interactions. This investigation
indicates that NMR isotropic shifts might be beneficial in search of
interesting spin-electronic phases among a vast number of topological
nontrivial half-Heusler semimetals.
