The effect of O2 preadsorption on the rate of H2 absorption on the surface of rare earths (La, Ce, Tb, Dy) at 298 K

Hydrogen absorption kinetics and mechanisms of rare earths (La, Ce, Pr, Nd, Tb, Dy) in the H2O surface reaction at room temperature

“…This systematic tendency in the measured reactivities of H 2 O adsorption is quite different from those of the O 2 adsorption where the Ce surface exhibits much higher r O 2 than the surface of Tb or Nd [16]. The systematic change in the O 2 reactivity seems to be interpreted with respect to the readiness of the ionization potential of the metals [23].…”

“…Careful approach using a clean surface technique should be made in the investigation of the surface property. We have applied the Wagener method [7,8] using ultra high vacuum condition to evaluate the quantitative reactivity of a gas (H 2 , O 2 , N 2 , H 2 O) on the surface of a metal as a function of the amount of reacted gas for many metals such as transition metals (Ti, Ta, W, Fe [9,10], Co, Ni [11]), RE metals (La, Ce, Tb, Dy [12][13][14][15][16][17]), and RE-based alloys (LaNi 5 [11,[18][19][20], Sm 2 Fe 17 [21]). …”

Variable‐range hopping dc conduction in dysprosium oxide films grown on Si substrates

“…The reduction of relative permittivity of S500 relative to S300 can be explained by the structural variations due to the annealing and the formation of complex amorphous interlayer consisting of Si oxide and silicate (or mixture of Si oxide and dysprosium oxide) [15] of thickness, which can be estimated by using the in-series-capacitors model [16] to be at least 21.8 nm (or about 13% of the total film thickness). The strong increase of the relative permittivity of S500v can be explained by a large removing of chemisorbed hydroxyl (OH) groups, which contained in the film due to REO-hygroscopic nature of dysprosium oxide [17][18][19][20]. ) for S300, S500 and S500v samples.…”

Annealing effect on the dc transport mechanism in dysprosium oxide films grown on Si substrates

“…Thus, Dy oxide (as one of the REOs) has a high adsorption reactivity with hydrogen 26,27 in addition to its hygroscopic nature, which is realized by chemisorbed hydroxyl (OH) groups. Therefore, it can be concluded that the RP of the film is strongly reduced due to the existence of chemisorbed hydroxyl (OH) groups, which can be removed by annealing in a vacuum causing a large increase in the RP.…”