Crystal Structure, Magnetic Properties, and Platinum Incorporation in a 2H-Perovskite Ruthenate

2H-perovskites are distinguished by their unique structural features and various physical properties, which have continuously attracted considerable research interest in solid-state chemistry and condensed matter physics. One well-known example is the Sr4PtO6 (SPO) structure type, a member of the 2H-perovskite family. This material exhibits a quasi-one-dimensional chain structure along the c-axis, formed via face-sharing by alternating polyhedral octahedra and trigonal prisms. In this study, we report a previously unknown compound, Sr4Ru0.3Pt0.7O6 (SRPO), using the high-temperature flux method in a platinum crucible. SRPO inherits the structural features of its parent compound, SPO, and crystallizes in the trigonal crystal system with the R3̅c space group. The coexistence of ruthenium and platinum ions in the crystal structure of SRPO was confirmed by combining single-crystal X-ray diffraction and energy-dispersive X-ray spectroscopy analyses. Magnetic susceptibility and specific heat measurements revealed that SRPO exhibits no long-range magnetic order down to 1.8 K. Specific heat measurements further indicated a magnetic entropy (Sm) of 2.76 J mol–1 K–1, aligning with the theoretical value of 0.30Rln3. Our results provide a new chemical intuition for introducing magnetism into a nonmagnetic structure motif, expanding the scope of material systems for exploring low-dimensional magnetism.