Stability of Pyrochlore Oxides.

Minervini, L. ; Grimes, R. ; Sickafus, K.

Technical Information Center Oak Ridge Tennessee

关键词: Crystallography;    Contour plots;    Disorder reaction energies;    Charge transport;    Oxides;   

RP-ID  :  DE2001763366

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

A Contour plot of the disorder reaction energies across a wide variety of A(sub2)B(sub2)O(sub7) pyrochlore oxides has been produced using atomistic simulation calculations based on energy minimization techniques. Cations studied range from LU(sup3+) to La(sup3+) on the A site and Ti(sup4+) to Ce(sup4+) on the B site. The results relate the experimentally observed stability range of the pyrochlore structure to A and B cation size and disorder. Disorder enthalpies decrease dramatically with increasing B cation size whilst the rate of increase with A cation size depends markedly on the particular B cation. The association of anion Frenkel and cation antisite disorders is found to be of importance.