Self-assembled supported Co nanocrystals: The adhesion energy of face-centered-cubic Co on SrTiO3(001)-(2×2)

Abstract

We have investigated the structure and morphology of self-assembled cobalt nanocrystals supported on a SrTiO3(001)-(2×2) substrate using scanning tunneling microscopy. Nanocrystals with a truncated pyramid shape were imaged, allowing crystallographic identification of the cluster facets. These nanocrystals result from the epitaxial growth of fcc Co on SrTiO3(001). The dimension of the nanocrystal facets at equilibrium and an energy minimization calculation result in γadh=(3.96±0.37)J∕m2 for the adhesion energy of face-centered-cubic Co∕SrTiO3(001)-(2×2).

SrTiO3(001)−(5×5)−R26.6°reconstruction: A surface resulting from phase

“…7 The material is also noted for its photocatalytic 8 and optical properties. 9 Surface terminations of STO have been used as a substrate for the epitaxial growth of metal nanocrystals and thin films, [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] and for TiO x ͑Refs. 25-27͒ or SrO ͑Refs.…”

A review of wetting versus adsorption, complexions, and related phenomena: the rosetta stone of wetting

“…Initially, the Winterbottom analysis was used only in isolated studies [51][52][53][54]. The major limitation arises from the demand that the examined system consist of a single crystal particle thermodynamically equilibrated and having a flat interface which is co-planar with the substrate surface [55].…”

Growth and micromagnetism of self-assembled epitaxial fcc(111) cobalt dots

“…Prior reports of self-assembled Co dots exist however with a rather flat shape and with a much smaller size so that facets cannot be identified and/or vortices do not form [29][30][31]. Larger dots were reported, however with no thorough magnetic characterization [32].…”

“…There exists no prior quantitative discussion of fcc Co surface energies based on supported nanocrystals. Silly et al [31] simply report the existence of both {111} and {100} facets for Co nanocrystals on SrTiO 3 (001), and Benamara et al report {111}, {100} and {110} facets for fcc Co(001) dots self-assembled on MgO(001) [32]. It is often argued that surface energy increases for orientations with more open planes, so that we would expect γ 111 < γ 100 < γ 110 [43].…”

“…We consider as unknowns ∆γ = γ S − γ int , and the energy of the facets identified with RHEED and AFM: γ 111 , γ 110 and γ 100 . Notice that another choice instead of ∆γ would be to use the adhesion energy γ * = γ 111 + γ S − γ int [31]. Only ratios may be determined, which leaves three dimensionless unknowns.…”