Phase-transition analysis through soft-phonon-polariton behavior in the temporal domain: A1-symmetry investigation of the PbTiO3 perovskite. [electronic resource] - Physical review. B, Condensed matter May 1993 - 11027-11030 p. digital Publication Type: Journal Article ISSN: 0163-1829 Standard No.: 10.1103/physrevb.47.11027 doi