  We present ultra-high-resolution dilatometric studies in magnetic fields on a
quasi-two-dimensional organic conductor
$\kappa$-(D8-BEDT-TTF)$_{2}$Cu[N(CN)$_{2}$]Br, which is located close to the
Mott metal-insulator (MI) transition. The obtained thermal expansion
coefficient, $\alpha(T)$, reveals two remarkable features: (i) the Mott MI
transition temperature $T_{MI}$ = (13.6 $\pm$ 0.6)\,K is insensitive to fields
up to 10\,T, the highest applied field; (ii) for fields along the interlayer
\emph{b}-axis, a magnetic-field-induced (FI) phase transition at $T_{FI}$ =
(9.5 $\pm$ 0.5)\,K is observed above a threshold field $H_c \sim$ 1 T,
indicative of a spin reorientation with strong magneto-elastic coupling.

Strongly Correlated Electrons;Superconductivity