  The tungsten ditelluride WTe2 was suggested to belong to the Weyl semimetal
family. We studied 125Te spin-lattice relaxation and NMR spectra in a WTe2
single crystal within a large range from 28 K up to room temperature.
Measurements were carried out on a Bruker Avance 500 NMR pulse spectrometer for
two orientations of the crystalline c axis, parallel and perpendicular to
magnetic field. Relaxation proved to be single-exponential. The relaxation time
varied depending on the sample position in magnetic field and frequency offset.
The relaxation rate increased about linearly with temperature below 70 K
however the dependence became nearly quadratic at higher temperatures. The
relaxation rate within the total temperature range was fitted using a
theoretical model developed in [41] for Weyl semimetals and assuming the
decrease of the chemical potential with increasing temperature. The results
obtained for 125Te spin-lattice relaxation evidence in favor of the topological
nontriviality of the WTe2 semimetal. The 125Te NMR spectra agreed with the
occurrence of nonequivalent tellurium sites and varied insignificantly with
temperature.
