Spin-glass behavior in Li₃NiCuBiO₆: a two-dimensional distorted honeycomb-lattice

Abstract

We report a detailed experimental study on the structural and magnetic properties of Li3NiCuBiO6 by means of various characterization techniques. It crystallizes into a monoclinic crystal structure composed of a layered magnetic honeycomb lattice along the c-axis. The existence of a glassy state below 4 K is indicated by dc and ac susceptibility measurements. Magnetic contribution to the total heat capacity also peaks around the freezing temperature, and its linear temperature dependence backs our claim of a glassy state in the compound. The calculated magnetic entropy unveil that only ∼ 26 % of the total entropy is released for the system (S = 3/2) and a tremendous amount of spin entropy is retained in the system. Further, analysis of the frequency-dependent freezing temperature with the help of power law confirms the presence of a spin glass state. Moreover, the appearance of magnetic memory and relaxation effect below freezing temperature manifest the development of the system via a large number of intermediate metastable states. All these measurements confirm the spin-glass behavior of the compound. We consider the presence of different magnetic atoms in honeycomb lattice as the main driving factor for the spin-glass ground state.

Spin-Cluster Glassy and Long-Range Ordered Magnetic States in Honeycomb-Layered Compositionally Complex Oxides Na3–xLixT2SbO6 (T = Cu1/3Ni1/3Co1/3)

“…Several quasi-binary solid solutions A 3 M 2– x M′ x XO 6 have been studied, − but we could not find any report on magnetism of A 3 M 2 XO 6 with a combination of more than two M 2+ cations. The only known work on truly high-entropy Na 3 M 2 SbO 6 materials combining up to five M cations is devoted to photocatalysis and does not report magnetic properties.…”

“…The Li-substituted compounds evidence hysteretic behavior most pronounced in Li 3 T 2 SbO 6 . These dependences are of characteristic S-shape typical for spin-glass or spin-cluster systems. ,− The M ( H ) curve in Na 3 T 2 SbO 6 is nonhysteretic, showing the spin-flop transition in moderate magnetic field μ 0 H = 3.2 T, which corresponds to the maximum in the d M /d H curve. At μ 0 H = 9 T, the magnetization M in all compounds is still far from the saturation value estimated to be higher than 4 μ B .…”