Self-recovery function of Sc–O/W() system as Schottky emitter

Self‐recovery function of p(1×1)‐Sc‐O/W(100) system used as Schottky emitter

“…It has been confirmed already that the decrease of the Sc LMM and O KLL peak intensities at step (iv) is due to the diffusion of Sc-O complexes into bulk W(100). 11 These tendencies of the variation of the AES p-p intensities and the LEED patterns at steps (i)-(iv) are almost identical to those reported previously. 9 -11 By heating at ¾1600 K for ¾20 min after step (iv) (step (v)), marked increase of the Sc LMM and O KLL peak intensities and a decrease of the W NVV peak intensity were observed, as seen in Fig.…”

“…These results revealed that the Sc-O/W(100) surface prepared by heating at ¾1700 K has the self-recovery function against sputtering by residual gas ions at the operating temperature. Note that the surface properties damaged by ion irradiation at room temperature were confirmed to be recovered completely after heating at ¾1500 K. In addition, the Sc-O/W(100) surface prepared by heating at ¾1500 K shows the p 2 ð 1 -p 1 ð 2 structure (step (iv)) and has the self-recovery function at ¾1500 K. 11 These results revealed that the Sc-O/W(100) surfaces prepared by heating at both ¾1500 and ¾1700 K have the self-recovery function at ¾1500 K. These results indicate that the self-recovery function at high temperature is induced by the surface segregation of Sc-O complexes that diffused into the bulk during preparation of the Sc-O/W(100) surface at step (iv).…”

“…11,15,16 In order to investigate the effects of ion irradiation on the p 1 ð 1 -Sc-O/W(100) surface prepared by heating at ¾1700 K for 8 min (step v 0 ), irradiation of 0.5 keV Ar C ions at 2.0 ð 10 14 ions cm 2 was performed at room temperature and at ¾1500 K, the operating temperature of the Sc-O/W(100) emitter. The resultant LEED patterns observed before and after ion irradiation at room temperature and ¾1500 K are depicted in Fig.…”

Kinetics of surface atoms during phase transition of Sc–O/W(100) system at high temperature studied by Auger electron spectroscopy

“…Previous studies [4][5][6][7][8][9][10][11][12][13] have revealed that the Sc-O/W(1 0 0) surface has two phases with surface atomic arrangements of the (1 Â 1) and (2 Â 1)-(1 Â 2) structures at high temperature. The (2 Â 1)-(1 Â 2)-Sc-O/W(1 0 0) surface is formed by heating at 1500 K in oxygen atmosphere.…”

“…In this regard, the authors have been involved in the surface characterization of the Sc-O/W(1 0 0) system using Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), and work function measurement at high temperature [4][5][6][7][8][9][10][11][12][13]. Previous studies [4][5][6][7][8][9][10][11][12][13] have revealed that the Sc-O/W(1 0 0) surface has two phases with surface atomic arrangements of the (1 Â 1) and (2 Â 1)-(1 Â 2) structures at high temperature.…”