Field induced metamagnetic transitions in quasi-one-dimensional Ising spin chain CoV₂O₆

Abstract

We have investigated the temperature and magnetic field dependence of magnetization (M), specific heat (Cp), and relative sample length change (∆L /L0) for understanding the field-induced metamagnetic transitions in quasi-one-dimensional monoclinic (α phase) and triclinic (γ phase) CoV₂O₆ spin chains. With the application of external magnetic field, a sharp peak emerges in Cp(T) below TN = 15 K in α phase and a hump-like feature appears above TN = 6.5 K in γ 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 α phase. Though magnetization data indicate strong spin-orbit coupling for both phases, other measurements show that this effect is very weak for the γ phase.