Structure and stability of rare-earth and transition-metal oxides

The structural parameters of rare-earth oxides lanthania (La₂O₃) and ytterbia (YbO), and of transition-metal oxides yttria (Y₂O₃) and lutetia (Lu₂O₃), candidate replacements of silica as gate insulators in nanometric Si electronics, are determined via ab initio calculations. The stability against formation of silica, silicides, and silicates for these oxides in contact with silicon is also investigated: we find stability against silica and silicide formation, but not against silicates.