%0 Journal Article
%A Scigaj, Mateusz
%A Gázquez, Jaume
%A Varela Del Arco, María
%A Fontcuberta Griñó, Josep
%A Herranz Casabona, Gervasi
%A Sánchez Barrera, Florencio
%T Conducting interfaces between amorphous oxide layers and SrTiO_3(110) and SrTiO_3(111)
%D 2015
%@ 0167-2738
%U https://hdl.handle.net/20.500.14352/24360
%X Interfaces between (110) and (111)SrTiO_3 (STO) single crystalline substrates and amorphous oxide layers, LaAlO_3 (a-LAO), Y:ZrO_2 (a-YSZ), and SrTiO_3 (a-STO) become conducting above a critical thickness tc. Here we show that t_c for a-LAO is not depending on the substrate orientation, i.e. t_c (a-LAO/(110)STO) ≈ t_c(a-LAO/(111)STO) interfaces, whereas it strongly depends on the composition of the amorphous oxide: t_c(a-LAO/(110)STO) < t_c(a-YSZ/(110)STO) < t_c(a-STO/(110)STO). It is concluded that the formation of oxygen vacancies in amorphous-type interfaces is mainly determined by the oxygen affinity of the deposited metal ions, rather than orientational-dependent enthalpy vacancy formation and diffusion. Scanning transmission microscopy characterization of amorphous and crystalline LAO/STO(110) interfaces shows much higher amount of oxygen vacancies in the former, providing experimental evidence of the distinct mechanism of conduction in these interfaces.
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