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4d/5d transitional metal oxides with trimers can often be described by molecular orbitals and host interesting physics including charge density wave, quantum liquid phase, etc. [1, 2].  Our newly synthesized trimer lattice Ba₄Ru₃O₁₀ features an insulating state that is sensitive to small external DC currents and a sharp transition at T = 100 K that is independent of applied magnetic field up to μ₀H = 14 T. This behavior is in sharp contrast to that of its sister compound BaRuO₃ that is metallic without any long-range order.   The results will be presented and discussed in comparison with other 4d/5d trimer oxides.