Analysis of the electronic structure of Hf(Si0.5As0.5)As by X-ray photoelectron and photoemission spectroscopy

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

“…The plate-shaped habit of the Zr(Si0.6As0.4)As crystal is common to other compounds, such as Hf(Si0.5As0.5)As, that adopt the PbFCl-type structure in the tetragonal space group P4/nmm [17]. In analogy with this and related compounds, only the 2a site and not the 2c site is assumed to accommodate the disorder of Si and As atoms.…”

“…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].…”

Crystal Chemistry and Physical Properties of the Nonmagnetic Kondo Compound HfAs1.7Se0.2

“…Based on chemical considerations, this crystallographic position can be assumed to show a preferred tendency to be occupied by any silicon impurity, as already reported for the related compound Hf(Si 0.5 As 0.5 )As. [15] Although As and Se are basically indistinguishable with standard X-ray diffraction techniques, we have already obtained clear evidence from analogous systems that there is no significant amount of Se occupying the 2a site. [10] This assumption is confirmed by neutron diffraction data of the isotypic compound ZrAs 1.6Àd Se 0.4 [d = 0.02 (1)].…”

ARXPS study of the ion mobility through (HfO2)x(SiO2)1−x formed on air‐exposed HfSi0.5As1.5

“…From analysis based on laboratory XPS and photoemission spectroscopy using synchrotron radiation, a charge formulation of Hf 2+ (Si 0.5 As 1.5 ) 2− was proposed. [5] We report here a kinetic study of the oxidation of HfSi 0.5 As 1.5 in air at room temperature, which results in (HfO 2 ) x (SiO 2 ) 1−x as the predominant product. By use of angle-resolved X-ray photoelectron spectroscopy (ARXPS), the mobility of constituent atoms has been examined as they diffuse through this silicate layer.…”

“…[2] We have recently identified the new ternary compound HfSi 0.5 As 1.5 , which is metallic and represents one end-member of the phase Hf(Si x As 1−x )As, with a homogeneity range of 0.5 ≤ x ≤ 0.7. [5] It adopts the prevalent ZrSiS-type structure, which is built up from a stacking of square nets, with those nets containing the disordered Si/As1 atoms being twice as dense as those containing the Hf or As2 atoms (Fig. 1).…”