  We have studied the structural stability of Sc-substituted rare earth (R)
ferrites R1-xScxFeO3, and constructed a structural phase diagram for different
R and x. While RFeO3 and ScFeO3 adopt the orthorhombic and the bixbyite
structure respectively, the substituted compound R1-xScxFeO3 may be stable in a
different structure. Specifically, for R0.5Sc0.5FeO3, the hexagonal structure
can be stable for small R, such as Lu and Yb, while the garnet structure is
stable for larger R, such as Er and Ho. The formation of garnet structure of
the R0.5Sc0.5FeO3 compounds which requires that Sc occupies both the rare earth
and the Fe sites, is corroborated by their magnetic properties.
