Comment on "Monoclinic phase of PbZr0.52Ti0.48O3 ceramics: Raman and phenomenological thermodynamic studies" - art. no. 176102

Recently, Souza Filho el al. [A. G. Souza Filho, K. C. V. Lima, A. P. Ayala , I. Guedes, P. T. C. Freire, J. Mendes Filho, E. B. Araujo, and J. A. Eira s, Phys. Rev. B 61, 14 283 (2000)] reported a phase transition between mono clinic and tetragonal phases as a function of temperature in a PbZr0.52Ti0. 48O3 ceramic sample, observed by Raman spectroscopy. We show that their obs ervation has no relation to the phase transition and the anomaly they inter preted as an indication of a phase transition was due to the erroneous curv e fit procedure, which predicts a clearly observable phase transition for a ll tetragonal lead-zirconate-titanate ceramics, including lead titanate. A more appropriate way to study this phase transition phenomena by Raman spec troscopy is discussed.