Field induced metamagnetic transitions in quasi-one-dimensional Ising spin chain CoV$_{2}$O$_{6}$

We have investigated the temperature and magnetic field dependence of magnetization ($M$), specific heat ($C_p$), and relative sample length change ($\Delta L/L_0$) for understanding the field-induced metamagnetic transitions in quasi-one-dimensional monoclinic ($\alpha$ phase) and triclinic ($\gamma$ phase) CoV$_2$O$_6$ spin chains. With the application of external magnetic field, a sharp peak emerges in $C_p$($T$) below $T_N$$=$15 K in $\alpha$ phase and a hump-like feature appears above $T_N$$=$6.5 K in $\gamma$ phase due to the field-induced ferrimagnetic and ferromagnetic transitions, respectively. Strong field dependence of linear thermal expansion and large positive magnetostriction have been observed in $\alpha$ phase. Though magnetization data indicate strong spin-orbit coupling for both phases, other measurements show that this effect is very weak for the $\gamma$ phase.