Near-surface domain structures in uniaxially stressed SrTiO3

Weak uniaxial stress (<1 kPa) along the cubic [100] and [110] directions of SrTiO3 modifies significantly the domain structure near the crystal surface on cooling to the tetragonal phase. High-resolution x-ray rocking curves show that {110} oriented slabs have a preference of 'c' domains perpendicular to a small (001) surface. On heating from 10 K the domain population increasingly randomizes when the transition point is approached. In {100} oriented slabs the domain population is more random with little temperature dependence for nominally stress-free samples. Uniaxial stress along (001) increases the population of 'a' domains for T --> T-c. The 'c' domains have characteristically shorter length scales perpendicular to the surface than the larger 'a' domains. The rocking angle of 'c' domains has a much larger angular spread (ca 1 degrees) than those of 'a' domains.