Crystal Growth of the S =1/2 Antiferromagnet K2PbCu(NO2)6 Elpasolite

The elpasolite K₂PbCu(NO2)6is known for its two structural transitions at 281 K and 273 K. Single crystals of K₂PbCu(NO₂)₆ have been grown in aqueous solution, but the rapid nucleation rate and convective transport renders it difficult to obtain large high quality single crystals. We developed a gel method to grow K₂PbCu(NO₂)₆ Elpasolite with sizes up to 5x5x5 mm³, suitable for neutron diffraction measurements. Susceptibility measurements clearly show that the Jahn-Teller distortions at 286K and 273K with associated orbital ordering produce a linear chain Heisenberg antiferromagnetic system. The intrachain interaction strength has been derived from a Bonner-Fisher analysis that yielded a value of 5.4K.

This work was supported by the National Science Foundation, under award DMR-1534818. A portion of this work has been performed at the National High Magnetic Field Laboratory, which is supported by the National Science Foundation Cooperative Agreement.