Field-driven linear magnetoelectric coupling and entangled spin-phonon behavior in the antiferromagnetic spin-chain compound MnS b 2 O 4

Low-dimensional magnets are known for their intriguing magnetic properties, often intricately linked with a variety of other physical phenomena. In this study, we report that the spin-chain compound ${\mathrm{MnSb}}₂{\mathrm{O}}₄$ undergoes long-range antiferromagnetic (AFM) ordering at ${T}_N=52$ K. Analysis of neutron powder diffraction data reveals $A$-type AFM ordering with a magnetic space group of $C{c}^{\ensuremath{'}}cm$, associated with the magnetic point group ${m}^{\ensuremath{'}}\mathit{mm}$. The proposed magnetic structure is supported by first-principles density functional theory calculations, allowing a quantitative analysis of interatomic magnetic exchange interactions and providing crucial insights into the strength and nature of magnetic couplings. Interestingly, below ${T}_N$, a magnetic field-driven electric polarization with strong linear magnetoelectric coupling is observed, which is well supported by the magnetoelectric tensor associated with the m\ensuremath{'}mm symmetry. High-resolution synchrotron x-ray diffraction and Raman spectroscopy studies reveal a local structural distortion occurring below 150 K, which appears to be linked to the short-range AFM spin correlations prevailing well above ${T}_N$. Additionally, a significant phonon renormalization induced by spin ordering is observed, indicating substantial spin-phonon coupling in this system.