A quantum molecular dynamics study of the cubic phase of BaTiO3 and BaZrO3

✍ Scribed by W Münch; G Seifert; K.D Kreuer; J Maier

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 374 KB
• Volume: 97
• Category: Article
• ISSN: 0167-2738
• DOI: 10.1016/s0167-2738(97)00085-4

✦ Synopsis

High proton mobility in perovskite-type oxides of composition ABO strongly depends on the dynamics of the proton 3 environment, especially on the fluctuations of the oxide ion separations. The dynamics of the oxide host lattices of the model materials BaTiO , and BaZrO have been studied using quantum molecular dynamics simulations. The simulation method 3 3 has already been shown to yield numerical results in agreement with experimental findings for the cubic phase of BaCeO .

3 At elevated temperatures, rotational diffusion of the protons around the oxygen atoms in the plane perpendicular to the B-O-B axis is found. The free energy of the oxygen lattice vibrations is evaluated and the activation energy for proton transfer is estimated to be 0.45 eV for BaTiO , 0.69 eV for BaZrO , and 0.64 eV for BaCeO . 3 3 3