ARXPS study of the ion mobility through (HfO₂)_x(SiO₂)_1−x formed on air‐exposed HfSi_0.5As_1.5

Abstract

The oxidation of the (001) surface of HfSi 0.5 As 1.5 exposed to the atmosphere, as monitored by angle-resolved X-ray photoelectron spectroscopy (ARXPS), gives rise to a slightly Si-rich (HfO 2 ) x (SiO 2 ) 1−x film. As 2 O 3 and SiO 2 are present at the air-oxide interface, suggesting that both As and Si atoms can diffuse through the amorphous silicate film via vacancies, in the form of defects and interstitial sites. By exposing the surface over periods between 1 and 60 min, it was found that the oxidation of HfSi 0.5 As 1.5 follows logarithmic kinetics, indicating that the oxide film formed is passive.

Ternary arsenides Zr(Si As1−)As with PbCl2-type (0 ≤x≤ 0.4) and PbFCl-type (x= 0.6) structures

“…The tin-containing antimonides tend to be distinct, as exemplified by ZrSn x Sb 2−x (CrSi 2 -or PbCl 2 -types) [4,12], TiSnSb (Mg 2 Cu-type) [13,14], and Ti 11 Sn x Sb 8−x (Cr 11 Ge 8 -type) [15]. In contrast, examples of the other pnictides (Pn = P, As, Bi) have been relatively sparse so far: Hf 27 Si 6 P 10 (own type) [16], Hf(Si 0.5 As 0.5 )As (PbFCltype) [17,18], Zr 5 Sn 3 P or Zr 5 Sn 3 As (stuffed Mn 5 Si 3 -type) [19], and "Ti 3 SnBi" (unknown structure) [20,21]. The Ti-(Si,Ge)-Bi phase diagrams at 400 • C reveal no ternary phases [22].…”

Quaternary Germanide Arsenides ZrCuGeAs and HfCuGeAs

“…The derivation of the ZrCuSiAs‐type as a filled PbFCl‐type structure was recognized early on 2. Indeed, there do exist ternary PbFCl‐type arsenides Zr(Si 0.6 As 0.4 )As and Hf(Si 0.5 As 0.5 )Asthat could be regarded as the host structures of ZrCuSiAs and HfCuSiAs, respectively, in which tetrahedral voids are filled by copper atoms 7–9. However, the relationship is not strict because, as implied by the formulas, the silicon and arsenic atoms are partially disordered in the ternary compounds but ordered in the quaternary compounds.…”