Structure-property relationship in layered BaMn2Sb2 and Ba2Mn3Sb2O2

Layered transition-metal compounds have received great attention owing to their physical properties. Here, we present the structural, electronic, thermal, and magnetic properties of $\mathrm{BaM}{\mathrm{n}}₂\mathrm{S}{\mathrm{b}}₂$ and $\mathrm{B}{\mathrm{a}}₂\mathrm{M}{\mathrm{n}}₃\mathrm{S}{\mathrm{b}}₂{\mathrm{O}}₂$ single crystals, both with the layered structure analogous to high-temperature Cu- and Fe-based superconductors. While the Mn moment in the $\mathrm{MnS}{\mathrm{b}}₄$ tetrahedral environment forms a long-range $G$-type antiferromagnetic (AFM) ordering in both $\mathrm{BaM}{\mathrm{n}}₂\mathrm{S}{\mathrm{b}}₂$ (${T}_{\mathrm{N}1}\ensuremath{\approx}443\phantom{\rule{0.16em}{0ex}}\mathrm{K}$) and $\mathrm{B}{\mathrm{a}}₂\mathrm{M}{\mathrm{n}}₃\mathrm{S}{\mathrm{b}}₂{\mathrm{O}}₂$ (${T}_{\mathrm{N}1}\ensuremath{\approx}314\phantom{\rule{0.16em}{0ex}}\mathrm{K}$), a short-range AFM order is found in the intercalated $\mathrm{Mn}{\mathrm{O}}₂$ layer at a much lower temperature $({T}_{\mathrm{N}2}\ensuremath{\approx}60\phantom{\rule{0.16em}{0ex}}\mathrm{K})$ coexisting with long-range $G$-type order in $\mathrm{MnS}{\mathrm{b}}₄$ layer in $\mathrm{B}{\mathrm{a}}₂\mathrm{M}{\mathrm{n}}₃\mathrm{S}{\mathrm{b}}₂{\mathrm{O}}₂$. The directions of the ordered moments in these two magnetic sublattices of $\mathrm{B}{\mathrm{a}}₂\mathrm{M}{\mathrm{n}}₃\mathrm{S}{\mathrm{b}}₂{\mathrm{O}}₂$ are perpendicular to each other, even though the system is electrically conductive. The $G$-type AFM order in $\mathrm{MnS}{\mathrm{b}}₄$ layers in both compounds is distinct from the stripe-like order in Fe-based superconductors, but the in-plane magnetic structure in $\mathrm{Mn}{\mathrm{O}}₂$ layers of $\mathrm{B}{\mathrm{a}}₂\mathrm{M}{\mathrm{n}}₃\mathrm{S}{\mathrm{b}}₂{\mathrm{O}}₂$ is found to be similar to that in the cuprates. Our study reveals the significant and distinct roles of the $\mathrm{Cu}{\mathrm{O}}₂$- and $\mathrm{FeA}{\mathrm{s}}₄$-type transition metal layers in the structure and their magnetic and electronic properties.