Iron is the most important impurity in Earth-forming minerals. Although it is well known iron influences their thermodynamics and elasticity significantly, effects at high pressures, in particular on elasticity, are still almost uncertain. Several complexities such as multi-valence, magnetism, high/low-spin problem, etc. introduced by iron make their high-pressure investigation substantially difficult both experimentally and theoretically. These complexities basically come from the strongly correlated nature of the iron (transition metal) oxide bonding. Using a rotationally invariant formulation of LDA+U with internally consistent U, we have recently succeeded in first principles studies of (Mg,Fe)-silicate perovskite and magnesiowustite, most abundant lower mantle phases. This technique will open a gate to clarify some important unresolved issues observed in LM.
問い合わせ先：土屋 卓久 TEL （089）927-8198
E-mail takut@sci.ehime-u.ac.jp
