Magnetic susceptibility and heat capacity of a quasi-spin chain compound, Li2CuO2

Abstract

Magnetization and heat capacity ($C_p$) measurements were performed on blade-shaped single crystals of Li${}_2$CuO${}_2$, a one-dimensional spin-chain compound synthesized via the flux method. The magnetization and heat capacity measurements confirm a long-range antiferromagnetic transition at $T_N$ = 9.3 K. The magnetic susceptibility, $\chi$ with magnetic field applied parallel (${\chi }_{\parallel b}$) and perpendicular (${\chi }_{\perp b}$) to the spin chain direction (crystallographic $b$-axis) is reported. $\chi \left(T\right)$ measurements reveal anisotropic behavior, with ${\chi }_{\perp b}$ $>{\chi }_{\parallel b}$ in the temperature range $T_N<T<350$ K, with a ratio of ${\chi }_{\perp }/{\chi }_{\parallel }$ = 1.15 at 300 K and with ${\chi }_{\perp b}$ $<{\chi }_{\parallel b}$ at $T=2$ K, with a ratio of ${\chi }_{\perp }/{\chi }_{\parallel }$ = 0.86 at 2 K. Unlike the previous studies reporting ferromagnetic components at low temperatures, we report the absence of a ferromagnetic ordering at low temperatures.