⁵¹V NMR studies on single crystal of A15 superconductor V₃Si

The Martensitic transformation (MT) in A15 binary-alloy superconductor V₃Si is a second-order, displacive structural transition from cubic to tetragonal symmetry, at temperature T_m a few K above the superconducting transition temperature T_c = 17 K. Though studied extensively, the MT has not yet been conclusively linked with a transition to superconductivity, while V₃Si continues to be of current interest. Previous NMR studies on the MT in V₃Si have been on powder samples, and with little emphasis on temperature dependence during transformation. Here we study a high-quality single crystal, where quadrupolar splitting and Knight shift of NMR spectra for ⁵¹V allowed us to distinguish between transverse chains of V as a function of temperature. This capability has led to evidence of coexistence of transformed and untransformed phases over a few K below and above T_m [Gapud et al., Physica C, vol. 602, 1354137], as well as new details regarding the evolution of the Knight Shift and of the longitudinal relaxation time T1 across this transition, as will be reported and discussed.