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arXiv · 1404.4579

Evolution of Magnetism in the $Na_{3-d}Na_{1-x}Mg_xIr_2O_6$ Series of Honeycomb Iridates

D. C. Wallace·C. M. Brown·T. M. McQueen
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Abstract

The structural and magnetic properties of a new series of iridium-based honeycomb lattices with the formula Na3-delta(Na1-xMgx)Ir2O6 (x = 0 to 1) are reported. As x and delta are increased, the honeycomb lattice contracts and the strength of the antiferromagnetic interactions decreases systematically due to a reduction in Ir-O-Ir bond angles. Samples with imperfect stoichiometry exhibit disordered magnetic freezing at temperatures Tf between 3.4 K and 5 K. This glassy magnetism likely arises due to the presence of non-magnetic Ir3+, which are distributed randomly throughout the lattice, with a possible additional contribution from stacking faults. Together, these results demonstrate that chemical defects and non-stoichiometry have a significant effect on the magnetism of compounds in the A2IrO3 materials family.

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D. C. Wallace, C. M. Brown, T. M. McQueen. 2014-04-17. Evolution of Magnetism in the $Na_{3-d}Na_{1-x}Mg_xIr_2O_6$ Series of Honeycomb Iridates. https://doi.org/10.1016/j.jssc.2014.03.013

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