Structural and physical properties evolution in the 6H BaRu1−xMnxO3 synthesized under high pressure

Molecule-like cluster magnetism and cationic order in the new hexagonal perovskite Ba4Sn1.1Mn2.9O12

The new hexagonal perovskite phase of composition Ba₄Sn_1.1Mn_2.9O₁₂ has been synthesized by solid-state reactions at 1673 K. The crystal structure has been investigated using X-ray and neutron diffraction. The hexagonal perovskite structure has an ordered arrangement of Sn and Mn ions on the corner-sharing octahedral centers and the face-sharing octahedral centers respectively. Short Mn–Mn distances have been evidenced in the face-sharing trimer of MnO₆ octahedra. The magnetic susceptibility shows magnetic cluster behavior, with cluster formation temperature ∼220 K. Antiferromagnetic order has been observed at T_N ∼ 6 K. Ba₄Sn_1.1Mn_2.9O₁₂ is a semiconductor with a transport activation energy of 0.61 eV.

The new 12R hexagonal perovskite Ba₄Sn_1.1Mn_2.9O₁₂ shows molecular-like cluster magnetism and Sn/Mn cationic order.

New 10H perovskites Ba5Ln1−xMn4+yO15−δ with spin glass behaviour

New 10H perovskites Ba₅Ln_1−xMn_4+yO_15−δ with ordered arrangements of Ln and Mn ions and spin glass behavior were synthesized and investigated.

Structural and magnetic properties of Ba0.7Sr0.3Ru(1-x)Mn(x)O3 hexagonal perovskites

The structures and properties of Ba(0.7)Sr(0.3)Ru(1-x)Mn(x)O(3) perovskites have been investigated in samples prepared at 1300 degrees C in air. Two polytypes are found, a 6H phase for 0.2 < or = x < or = 0.4 and a 4H type for 0.6 < or = x < or = 1. The cell parameters and volume vary linearly in both solid solution ranges. Spin-freezing transitions up to 60 K are observed for the 6H samples, but the 4H materials show high temperature Néel transitions at 210 to 280 K.