We report evidence for phase coexistence of orbital orderings of different symmetry in ${\mathrm{SmVO}}_3$ by high resolution x-ray powder diffraction. The phase coexistence is triggered by an antiferromagnetic ordering of the vanadium spins near 130 K, below an initial orbital ordering near 200 K. The phase coexistence is the result of the intermediate ionic size of samarium coupled to exchange striction at the vanadium spin ordering.

• Received 10 June 2005

DOI:https://doi.org/10.1103/PhysRevLett.96.036401