Search

The growth of single crystals of MoS2and WS2by materials transport through a liquid salt flux made from a low-melting mixture of NaCl and CsCl is presented. The crystals are structurally characterized by single-crystal X-ray diffraction, which reveals that the 2H-MoS2crystals contain a very small percentage (about 3%) of 3R intergrowths and that the 2H-WS2crystals display less than 1% of 3R intergrowths. Characterization of the crystals by scanning electron microscopy is presented as are photoluminescence spectra of exfoliated monolayers that show that MoS2crystals grown by this method are superior in quality to commercially available MoS2crystals and equivalent to the current state of the art.

A previously unreported family of electrically insulating rare-earth borates, RbBaR(BO3)2(R= Y, Gd–Yb), was designed and then successfully obtained by traditional solid-state reaction. They crystallize in a monoclinic crystal system space group P21/m(No. 11). They feature triangular planar rare-earth (R) lattices, which are part of, for example, [Yb(BO3)2]3–infinite 2D layers. These R-based triangular lattices are stacked with layers of crystallographically ordered Rb and Ba atoms to build the 3D structures. Polycrystalline samples of RbBaR(BO3)2were used to study the elementary magnetic properties, and millimeter-size RbBaYb(BO3)2single crystals were grown by spontaneous nucleation for further anisotropic magnetic characterization. Antiferromagnetic spin interactions are observed for all magnetic compounds, and no long-range magnetic ordering is found down to 1.8 K. Our results suggest that this RbBaR(BO3)2(R= Gd–Yb) family may be of further interest both experimentally and theoretically as highly geometrically frustrated magnets.