The effect of a strong magnetic field on the tetragonal phase of ${\mathrm{V}}_2$Si is examined theoretically using the linear-chain model of Labbé and Friedel. A careful examination of the free energy of this system shows that, for any temperature below 17.4°K, some applied magnetic field will produce a discontinuous structural transformation from the state with $\frac{c}{a}>1\mathrm{}$ to that with $\frac{c}{a}<1\mathrm{}$. At $T=17.4\mathrm{}$°K, the needed field is $H\cong 275$ kOe.

• Received 11 December 1972

DOI:https://doi.org/10.1103/PhysRevLett.30.1245