1305.5027 (M. Nandi et al.)

Field-induced spin-structural transition and giant magnetostriction in
Ising chain $α$-CoV$_2$O$_6$    [PDF]

M. Nandi, N. Khan, D. Bhoi, A. Midya, P. Mandal

We have measured magnetization, specific heat ($C_p$), and sample length change ($\Delta L/L$) for understanding the field-induced spin-structural change in quasi-one-dimensional antiferromagnetic (AFM) spin chain $\alpha$-CoV$_2$O$_6$. Analysis of $C_p$($T$) shows that an effective $S$$=$1/2 Ising state is realized below 20 K, though the magnetic fluctuations persist well above $T_N$. Both $C_p$ and $\Delta L/L$ exhibit strong $H$ dependence in the AFM state. With increasing $H$, a sharp and symmetric peak emerges below $T_N$ due to the field-induced first order magnetic transition. The large magnetostriction and the emergence of new peak below $T_N$ suggest strong spin-lattice coupling in $\alpha$-CoV$_2$O$_6$.

View original: http://arxiv.org/abs/1305.5027