  We demonstrate a unique approach to test the signature of the nodal-line
physics by thermodynamic methods. By measuring magnetic susceptibility in ZrSiS
we found an intriguing temperature-driven crossover from dia- to paramagnetic
behavior. We show that the anomalous behavior represents a real thermodynamic
signature of the underlying nodal-line physics through the means o chemical
pressure (isovalent substitution of Zr for Hf), quantum oscillations, and
theoretical model ng. The anomalous part of the susceptibility is orbital by
nature, and it arises due to the vicinity of the Fermi level to a degeneracy
point created by the crossing of two nodal lines. Furthermore, an unexpected
Lifshitz topological transition at the degeneracy point is revealed by tuning
the Ferm level. The present findings in ZrSiS give a new and attractive
starting point for various nodal-lin physics-related phenomena to be tested by
thermodynamic methods in other related materials.
