Thermal-induced change in surface termination of DyScO3(110)

Ferroelectric domain structure of anisotropically strained NaNbO3 epitaxial thin films

“…Before introducing the perovskite substrates into the reactor chamber, they were annealed in pure oxygen gas flow at 1050 C for NdGaO 3 , GdScO 3 , and DyScO 3 and at 1150 C for TbScO 3 in order to generate a regular step-andterrace surface structure with $200 nm broad atomically smooth terraces and step heights of one monolayer ($4 Å ). 31,32 All NaNbO 3 films with thickness ranging from $10 nm to 140 nm were deposited at a substrate temperature of 700 C and an O 2 to Ar ratio in the gas phase of 0.63 at a gas pressure of 2.6 Â 10 3 Pa. The Na(thd) ((thd) ¼ 2,2,6,6-tetramethyl-3, 5-heptanedione) and Nb(EtO) 5 ((EtO) 5 ¼ penta-ethoxide) metal-organic precursors dissolved in dry toluene with a concentration of 0.01 M were evaporated at 230 C and 190 C, respectively, and transported by Ar as carrier gas into the reactor chamber via a showerhead.…”

Reconstructions at complex oxide interfaces

“…This is consistent with the observations of Dirsyte et al. [33] Note that the temperature during thin film growth is typically below the temperature where major bulk diffusion occurs and, therefore, should not result in unintended mixed termination of the surface. Since only one of the atomic layers seemed to be removed by 12 M NaOH (aq) (illustrated in Fig.…”

“…As mentioned before, exchanging this order gives another difficulty: Dy diffusion to the surface during high temperature annealing, resulting in mixed termination. [14,33] Therefore, an additional etching step after annealing is introduced, which roughens the topmost layer at the nanometer scale (see Fig. 2.8b).…”

“…[8,[28][29][30] However, surface treatments for perovskite-type scandates have hardly been addressed in literature. [31][32][33] Recently, Dirsyte et al showed that annealing of DyScO 3 at high temperatures in …”

“…[33] By prolongating the annealing time to more than 100 minutes, they observed a change of the predominant cation at the topmost surface layer. Annealing DyScO 3 substrates in an Ar flow resulted in surfaces with mainly Sc termination, independent of the annealing time.…”