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arXiv · 1608.06205

Model analysis of magnetic susceptibility of Sr$_2$IrO$_4$ - 2D $J_{\rm eff}$ = 1/2 Heisenberg system with competing interlayer couplings

Tomohiro Takayama·Akiyo Matsumoto·George Jackeli·Hidenori Takagi
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Abstract

We report the analysis of magnetic susceptibility $\chi$($T$) of Sr$_2$IrO$_4$ single crystal in the paramagnetic phase. We formulate the theoretical susceptibility based on isotropic Heisenberg antiferromagnetism incorporating the Dzyaloshinsky-Moriya interaction exactly, and include the interlayer couplings in a mean-field approximation. $\chi$($T$) above $T_{\rm N}$ was found to be well described by the model, indicating the predominant Heisenberg exchange consistent with the microscopic theory. The analysis points to a competition of nearest and next-nearest neighbor interlayer couplings, which results in the up-up-down-down configuration of the in-plane canting moments identified by the diffraction experiments.

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Tomohiro Takayama, Akiyo Matsumoto, George Jackeli, Hidenori Takagi. 2016-08-22. Model analysis of magnetic susceptibility of Sr$_2$IrO$_4$ - 2D $J_{\rm eff}$ = 1/2 Heisenberg system with competing interlayer couplings. https://doi.org/10.1103/physrevb.94.224420

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