Systematic investigation of spin ordering study in a frustrated 2D honeycomb SrMnTeO6 single crystals

Moovendaran K^1*, R. Kalaivanan¹, Raman Sankar¹

¹Institute of Physics, Academia Sinica, Taipei 11529, Taiwan, Taiwan

* Presenter:Moovendaran K, email:moovendaran@gmail.com

We report the successful growth of high-quality single crystals of SrMnTeO6 using a self-flux method. The structural, electronic, and magnetic properties of SrMnTeO6 are investigated by X-ray, thermodynamic, and nuclear magnetic resonance techniques in conjunction with density functional theory (DFT) calculations. Our studies reveal that SrMnTeO6 is a large bandgap semiconductor with ~ 2.39 eV and crystallizes in a non-centrosymmetric hexagonal structure (space group P6̅2m) involving edge-shared (Mn4+/Te6+)O6 cations randomly distributed in a trigonal prismatic environment. Alternating arrangements of (Mn/Te)6O18 and SrO6 octahedra along the c axis lead to the formation of a S = 3/2 honeycomb-like lattice. DFT calculations support a frustrated J1-J2 honeycomb magnet made of competing antiferromagnetic exchange interactions between the nearest and second nearest-neighbouring Mn4+ ions. The magnetic susceptibility and specific heat data evidence a weak long-range order at TN = 6.56 K. The estimated Curie-Weiss temperature ϴCW = −21.05 K indicates the presence of a sizable frustration. Further, both the magnetic entropy and the 125Te nuclear spin-lattice relaxation rate showcase that short-range spin correlations persist up to the Curie-Weiss temperature, signifying two-dimensional frustration arising from exchange frustration.

Keywords: Flux growth, Honeycomb lattice, Magnetic studies, Specific heat, Antiferromagnetic coupling