Martensitic transformation in V_3Si single crystal: ^51V NMR evidence for coexistence of cubic and tetragonal phases

A. A. Gapud; S. K. Ramakrishnan; E. L. Green; A. P. Reyes

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arXiv · 2204.03729

Martensitic transformation in V_3Si single crystal: ^51V NMR evidence for coexistence of cubic and tetragonal phases

A. A. Gapud·S. K. Ramakrishnan·E. L. Green·A. P. Reyes

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Abstract

The Martensitic transformation (MT) in A15 binary-alloy superconductor V_3Si, though studied extensively, has not yet been conclusively linked with a transition to superconductivity. Previous NMR studies have mainly been on powder samples and with little emphasis on temperature dependence during the transformation. Here we study a high-quality single crystal, where quadrupolar splitting of NMR spectra for ^51V allowed us to distinguish between spectra from transverse chains of V as a function of temperature. Our data revealed that (1) the MT is not abrupt, but rather there is a microscopic coexistence of pre-transformed cubic phase and transformed tetragonal phase over a few K below and above Tm, while (2) no pre-transformed phase can be found at Tc, and (3) the Martensitic lengthening of one axis occurs predominantly in a plane perpendicular to the crystal growth axis, as twinned domains.

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A. A. Gapud, S. K. Ramakrishnan, E. L. Green, A. P. Reyes. 2022-04-07. Martensitic transformation in V_3Si single crystal: ^51V NMR evidence for coexistence of cubic and tetragonal phases. https://arxiv.org/abs/2204.03729

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