Magnetic Ordering of Compositionally Complex Oxides Na₂Z₂TeO₆ (Z=Cu, Co, Ni, Zn, Fe)

Layered honeycomb oxides have attracted growing interest as model systems for exploring magnetic frustration and correlated behavior in low-dimensional lattices. Here, we investigate a family of compositionally complex oxides, Na₂Z₂TeO₆ (Z = Cu, Co, Ni, Zn, Fe), designed to probe the interplay between chemical disorder and magnetic ordering. A series of multicomponent compositions CCO-I Na₂(Ni₀.₅₀Cu₀.₂₀Zn₀.₁₀Fe₀.₁₀Co₀.₁₀)₂TeO₆, CCO-II Na₂(Ni₀.₅₀Fe₀.₁₀Co₀.₄₀)₂TeO₆, CCO-III Na₂(Ni₀.₅₀Zn₀.₁₀Fe₀.₁₀Co₀.₃₀)₂TeO₆, and CCO-IV Na₂(Ni₀.₅₀Cu₀.₁₀Zn₀.₁₀Fe₀.₁₀Co₀.₂₀)₂TeO₆ were synthesized by solid-state reaction. X-ray diffraction and Rietveld refinement confirm that all compounds adopt the P6₃/mcm structure, maintaining the layered honeycomb framework. Magnetic susceptibility measurements show a progressive suppression of long-range antiferromagnetic order, with Néel temperatures varying between ~14 K and ~25 K. Neutron Powder Diffraction models further validate the suppression of long-range magnetic order below the transition temperatures. The results highlight how cationic disorder and competing exchange interactions disrupt coherent spin alignment, suggesting a route toward emergent spin-glass-like behavior in layered high-entropy oxides.