Pb- and Ti-isotope Effects in Pb TiO₃ by Heat Capacity Measurement and Neutron Powder Diffraction

Abstract

The heat capacity and the crystal structure of perovskite lead titanate, PbTiO₃, have been analyzed by differential scanning calorimetry and neutron powder diffraction, respectively, in order to investigate the isotope effect. The ferroelectric transition temperature and the shape of the anomaly in the heat capacity due to phase transition changed by Pb- and Ti-isotope substitution. On the other hand, Rietveld refinement of the neutron diffraction data confirmed that the differences in the lattice parameters and the structural parameters among isotope-enriched and natural samples were not observed within experimental error below 500 K.

KEYWORDS:

• PbTiO₃
• ferroelectric phase transition
• isotope effects
• heat capacity
• neutron powder diffraction
• crystal structure
• lead
• titanium
• titanium oxides