Single crystal growth and anisotropic magnetic properties of Li${}_2$Sr[Li${}_{1-x}$Fe${}_x$N]${}_2$

Abstract

Up to now, investigation of physical properties of ternary and higher nitridometalates was severely hampered by challenges concerning phase purity and crystal size. Employing a modified lithium flux technique, we are now able to prepare sufficiently large single crystals of the highly air and moisture sensitive nitridoferrate $\mathrm{L}{\mathrm{i}}_2\mathrm{Sr}[\mathrm{L}{\mathrm{i}}_{1-\mathrm{x}}\mathrm{F}{\mathrm{e}}_{\mathrm{x}}\mathrm{N}{]}_2$ for anisotropic magnetization measurements. The magnetic properties are most remarkable: large anisotropy and coercivity fields of 7 Tesla at $T=2$ K indicate a significant orbital contribution to the magnetic moment of iron. Altogether, the novel growth method opens a route towards interesting phases in the comparatively recent research field of nitridometalates and should be applicable to various other materials.

10 pages, 5 figures, published open access in Inorganics, minor typos corrected