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arXiv · 1802.00964

Spin-specific heat determination of the ratio of competing first- and second-neighbor exchange interactions in frustrated spin-$\frac{1}{2}$ chains

Dayasindhu Dey·Manoranjan Kumar·Siân E. Dutton·Robert J. Cava·Zoltán G. Soos
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Abstract

The magnetic susceptibility $χ(T)$ of spin-1/2 chains is widely used to quantify exchange interactions, even though $χ(T)$ is similar for different combinations of ferromagnetic $J_1$ between first neighbors and antiferromagnetic $J_2$ between second neighbors. We point out that the spin specific heat $C(T)$ directly determines the ratio $α= J_2/|J_1|$ of competing interactions. The $J_1-J_2$ model is used to fit the isothermal magnetization $M(T,H)$ and $C(T,H)$ of spin-1/2 Cu(II) chains in LiCuSbO$_4$. By fixing $α$, $C(T)$ resolves the offsetting $J_1$, $α$ combinations obtained from $M(T,H)$ in cuprates with frustrated spin chains.

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Dayasindhu Dey, Manoranjan Kumar, Siân E. Dutton, Robert J. Cava, Zoltán G. Soos. 2018-02-03. Spin-specific heat determination of the ratio of competing first- and second-neighbor exchange interactions in frustrated spin-$\frac{1}{2}$ chains. https://doi.org/10.1103/physrevb.97.064407

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