1211.5215 (Erwin Hildebrandt et al.)

Physical properties and band structure of reactive molecular beam
epitaxy grown oxygen engineered HfO$_{2\pm x}$    [PDF]

Erwin Hildebrandt, Jose Kurian, Lambert Alff

We have conducted a detailed thin film growth structure of oxygen engineered monoclinic HfO$_{2\pm x}$ grown by reactive molecular beam epitaxy (MBE). The oxidation conditions induce a switching between ($\bar{1}11$) and (002) texture of hafnium oxide. The band gap of oxygen deficient hafnia decreases with increasing amount of oxygen vacancies by more than 1 eV. For high oxygen vacancy concentrations, defect bands form inside the band gap that induce optical transitions and $p$-type conductivity. The resistivity changes by several orders of magnitude as a function of oxidation conditions. Oxygen vacancies do not give rise to ferromagnetic behavior.

View original: http://arxiv.org/abs/1211.5215