Growth and magnetism ofConanometer-scale dots squarely arranged on aCu(001)−c(2×2)

Abstract

We have studied the growth and magnetism of two-dimensionally coupled nanometer-scale Co dots which are squarely arranged on a Cu(001)-c(2ϫ2)N surface. The morphology was analyzed by scanning tunneling microscopy, and the magnetization was studied using the magneto-optical Kerr effect. Well-ordered arrays of two monolayer ͑ML͒ thick Co dots interconnected by narrow 1 ML thick Co films can be grown by adjusting the deposited amount of Co. Here we used selective growth of Co at the clean Cu area of the surface, which consists of 5ϫ5 nm 2 N-adsorbed c(2ϫ2) patches separated by clean Cu lines of a few nm in width. The observed ferromagnetism in these arrays is considered to be mediated by narrow monolayer thick Co films on clean Cu lines. When the average thickness of Co exceeds 1.5 ML, 2 ML thick Co dots are connected with each other, and 1 ML Co films grow on the c(2ϫ2)N patches. For Co films with an average thickness between 1.8 ML and 2.1 ML, the magnetization is almost constant between 150 K and 370 K, and increases with decreasing temperature from 150 K. This result suggests that polarization is induced in the 1 ML Co film on c(2ϫ2)N patches below 150 K.

Growth, structural and optical properties of Cu3N films

“…Such self-assembled templates were subsequently used for the growth of magnetic nanostructures [7][8][9].…”

Surfaces: Two-Dimensional Templates

“…N layer Ag 5 × 5 I s l a n d s L o w Cu(1 0 0) [177] Reconstr. N layer Fe 5 × 5 I s l a n d s L o w Cu(1 0 0) [178,180] …”

“…This example once more proves the importance of kinetic control of the growth process, which is a common feature of the examples cited so far. Furthermore, the N/Cu(100) system has also been successfully employed as a template for the growth of Ag [175,176], Fe [177], and Co [176,[178][179][180].…”

Molecular scale structure formation by folding

“…The scanning tunneling microscope which can draw atomic scale structure on surfaces satisfies only the first [4,5]. The usual self-assembly satisfies only the second [6][7][8][9][10][11].…”