Abstract
Using a flux technique we have grown sizable single crystals of . With x rays and neutrons we have studied both the static and dynamic aspects of the tetragonal to orthorhombic structural phase transition; classic soft-phonon behavior is observed at the ((1/2, 1) / 2 , 0) zone boundary involving rotations of octahedra. The pure and lightly-doped single crystals show hopping conductivity, lnρ∼(/T, indicating that the electronic states at the Fermi energy are localized.
- Received 7 July 1987
DOI:https://doi.org/10.1103/PhysRevLett.59.1329
©1987 American Physical Society