The phase transformation behavior and physical properties of the technologically important PbZr1-xTixO3 (PZT) solid solution series are of great interest. For example, the large piezoelectric response of PZT (x = 0.45) makes this compound suitable for transducer applications. Understanding the physics of PZT at the atomic level would help in designing materials with improved performance and reliability. Ab initio statistical mechanics (AISM) is expected to be very useful for modeling PZT. In AISM, first principles calculations are used both to develop effective Hamiltonians which contain only the degrees of freedom that are relevant to the observed phase transitions and to determine the values of the parameters in the resultant model. We present the development of an effective Hamiltonian for PbZrO3 (PZ). PZ is an endmember compound of the PZT series. Its complicated 40-atom ground state will ultimately provide a sensitive test of the validity of an effective Hamiltonian. Using local density functional theory total energy and linear response calculations, we have determined that Pb motion, O motion, and the coupling be3tween the two are all important in driving the antiferroelectric phase transition in PZ.
Citation: First-Principles Effective Hamiltonians for PbZrO<sub>3</sub>
Pub Type: Others
antiferroelectrics, ferroelectrics, PbZrO<sub>3</sub>, PZT