STM atomic-scale characterization of the γ′-Al2O3 film on Ni3Al(111)

Effect of the Noble Metals Addition on the Oxidation Behavior of Ni3Al

“…At 900 and 1000°C, the k p values of both doped and undoped alloys tend to k p values where the formation of the θ-Al 2 O 3 phase may be possible in NiAl as reported by Brumm and Grabke [72]. At 1100°C, the k p values are concentrated at a point between the formation of θ-Al 2 O 3 and α-Al 2 O 3 ; an explanation for this behavior could be that, at this temperature, the stability of the α-Al 2 O 3 begins [18] and this tends to decrease the weight gain [70,71]. At 900°C and 1000°C, the k p value of the undoped alloy is similar to results reported by Lee and Kim [26] and Choi et al [73], and at 1100°C, it is similar to results of Kuenzly et al [74].…”

“…Al 2 O 3 forms internally due to inward diffusion of O 2− anions, while NiO is a p-type conductor, which preferably promotes conduction of cations [15][16][17]. Al 2 O 3 growth onto alloys such as Ni 3 Al can adopt different crystallographic arrangements: between 427 and 927°C, the γ-Al 2 O 3 phase is stable; until 1077°C, the θ-Al 2 O 3 phase is stable; and above 1077°C, the α-Al 2 O 3 phase is stable [18]. e θ → α transformation is accompanied by a change in the transport properties of the scale.…”

The growth of protective ultra-thin alumina layers on γ-TiAl(111) intermetallic single-crystal surfaces

“…In all series, the thickness of the alumina layer increases rapidly after the first exposure to oxygen to reach 0.7-0.8 nm after less than 3 min of exposure, and levels off afterwards to reach 1.3-1.5 nm at the most. This range of thickness is typical for the alumina layers formed under UHV conditions on other aluminide alloys (NiAl) [16][17][18][19][20][21][22]. It amounts to oxide films consisting of 3-7 monolayers of oxide.…”

Metal thin film growth on multimetallic surfaces: From quaternary metallic glass to binary crystal

“…One should note that one of the significant features of the TM aluminides is that they can serve as templates for the growth of well-ordered oxide layers [62][63][64][65][66]. Due to their importance in a broad range of applications, thin oxide layers and their surfaces have attracted considerable attention.…”

“…Specifically, upon direct oxidation of clean alloy surfaces at high temperature, well-ordered thin alumina films have been identified on Ni 3 Al(111) [66], NiAl(111) [65], NiAl(001) [64], NiAl(110) [62,63] and FeAl(110) [61].…”