Effects of cation-size variance on spin and orbital orders in Eu 1 − x (La 0.254 Y 0.746 ) x VO 3

We have investigated the $R$-ion ($R$ $=$ rare earth or Y) size variance effect on spin/orbital order in Eu${}_{1\ensuremath{-}x}$(La${}_{0.254}$Y${}_{0.746}$)${}_{x}$VO${}_{3}$. The size variance disturbs one-dimensional orbital correlation in $C$-type spin/$G$-type orbital ordered states and suppresses this spin/orbital order. In contrast, it stabilizes the other spin/orbital order. The results of neutron and resonant x-ray scattering denote that in the other ordered phase, the spin/orbital patterns are $G$ type/$C$ type, respectively.