화학공학소재연구정보센터
Thin Solid Films, Vol.565, 261-266, 2014
Holmium titanium oxide thin films grown by atomic layer deposition
Thin solid holmium titanium oxide films were grown by atomic layer deposition at 300 degrees C on silicon substrates. The precursors used were Ho(thd)(3), Ti(OCH(CH3)(2))(4) and O-3. The composition of the films was varied via changing the holmium-titanium ratio by variation of relative amounts of the sequential deposition cycles of constituent oxides, i.e. Ho2O3 and TiO2. The constituent oxides alone were crystallized in as-deposited states. After mixing the Ho2O3 or TiO2 layers the films were amorphous but were crystallized after annealing at 800-1000 degrees C, mostly transforming into the Ho2Ti2O7 phase. The stoichiometric ratio of 1: 1 between Ti and Ho contents was achieved by application of at least twice as many Ho2O3 deposition cycles as TiO2 cycles. Magnetometry revealed that saturation magnetization could be observed in the films containing lower amounts of holmium compared to titanium. (C) 2014 Elsevier B.V. All rights reserved.