Phase Separation of Alkoxy‐derived (Ti,Sn)O₂ Oriented Thin Films

Abstract

Oriented (Ti,Sn)O 2 thin films with modulated microstructure were successfully synthesized on sapphire substrates by using sol-gel processing combined with spinodal decomposition. The degree of orientation of (Ti 0.5 Sn 0.5 )O 2 thin films increased in the following order: sapphire (0001),, and (0112). (Ti 0.5 Sn 0.5 )O 2 thin films underwent spinodal decomposition at 900°C by annealing. The variation of the 2 value of the 202 reflection of (Ti 0.5 Sn 0.5 )O 2 films showed the typical behavior of spinodal decomposition. The rate of spinodal decomposition of the (Ti 0.5 Sn 0.5 )O 2 films on sapphire (1120) was faster than that on sapphire (0112) substrates. The characteristic modulated microstructure was observed for the spinodally decomposed (Ti 0.5 Sn 0.5 )O 2 films on sapphire (0112) substrates by transmission electron microscopy. (Ti 0.3 Sn 0.7 )O 2 films on sapphire (0112) substrates were binodally decomposed during annealing at 1300°C.

Gas Semiconducting Sensors Based on Metal Oxide Nanocomposites

“…The second category includes mixed oxides, which form solid solutions. An example of such a system is the mixture of TiO 2 and SnO 2 , which form solid solutions over the entire range of compositions but only above a certain critical temperature (Edelman, et al, 2000;Arakawa, et al, 1997). The third group consists of systems that give neither individual compounds nor solid solutions.…”

Suppressing spinodal decomposition by incorporation of reduced graphene oxide into (Sn0.5Ti0.5)O2 solid solution

“…Spinodal decomposition is one of the methods of phase separation leading to the unique microstructure by a nearly sinusoidal composition modulation at the nanometer level, which is a general phenomenon observed in various systems such as metallic alloys, polymers, glasses, and metal oxides [1][2][3][4][5]. Although the spinodal decomposition in ceramic materials is relatively rare, it has been known to happen particularly in several metal oxide/non-oxide systems: e.g., SnO 2 -TiO 2 , TiO 2 -VO 2 , Al 2 O 3 -Cr 2 O 3 , CoFe 2 O 4 -Co 3 O 4 , and SiC-AlN [2,5]. Among them, SnO 2 -TiO 2 solid solution is the representative system found from the early study of spinodal decomposition in ceramic materials, where it has a tetragonal rutile-type structure and the well-defined miscibility gap which is a phase-separation region by spinodal decomposition at its phase diagram [2-4, 6, 7].…”

“…Moreover, such aliovalent dopants can affect particle size and surface morphology for the change in microstructure via phase separation [19]. For thin-film materials, it is known that the rate of spinodal decomposition in (Sn 0.5 Ti 0.5 )O 2 thin films, grown on single-crystalline sapphire substrates, is dependent on the type of substrate and the preferred orientation of film [2]. Similarly, different modes of spinodal decomposition and film microstructure can be achieved depending on the type of sapphire substrate in TiO 2 -VO 2 thin films [20].…”

Magnetic-field-induced phase separation via spinodal decomposition in epitaxial manganese ferrite thin films

“…SD is a general phenomenon observed in various systems, such as alloys, glasses, and oxides. It is well-established theoretically and experimentally that SD could occur generally in material systems whose phase diagram shows a miscibility gap, such as Al 2 O 3 -Cr 2 O 3 [9], TiO 2 -SnO 2 [10], HfO 2 -SiO 2 [11], and CoFe 2 O 4 -Co 3 O 4 [12,13]. …”