Verwey-type transition within the Pb3Rh7−xMnxO15 solid solution

A complete solid solution was found between isostructural Pb{sub 3}Mn{sub 7}O{sub 15} and Pb{sub 3}Rh{sub 7}O{sub 15}. Single-crystals of two members of the solid solution Pb{sub 3}Rh{sub 7-x}Mn{sub x}O{sub 15} (x=1.07 and 2.26) were grown and their crystal structures were determined. The Verwey-type transition for Pb{sub 3}Rh{sub 7}O{sub 15} at 185 K remains with a 3% substitution of Mn for Rh but disappears with 4% substitution of Mn for Rh. The magnetic ordering temperature found for Pb{sub 3}Mn{sub 7}O{sub 15} at about 70 K is maintained at a 43% substitution of Rh for Mn but has disappeared for 57% substitution of Rh for Mn. The unit cell volume of this layered structure contracts with increasing x for Pb{sub 3}Rh{sub 7-x}Mn{sub x}O{sub 15} phases, but the structure actually expands in the direction perpendicular to the layers due to increased separation between the layers. - Graphical abstract: A complete solid solution is formed between isostructural Pb{sub 3}Mn{sub 7}O{sub 15} and Pb{sub 3}Rh{sub 7}O{sub 15}. The effect of Mn substitution for Rh on the previously discovered Verwey-type transition in Pb{sub 3}Rh{sub 7}O{sub 15} is described.