• Physics 15, s113
By epitaxially rising movies from colloids, researchers present that they will monitor interactions and behaviors of the particles which might be tough—and generally not possible—to seize for comparable movies grown from atoms.
Many elements in right this moment’s applied sciences are constructed by controlling the meeting of elementary constructing blocks. For instance, in “epitaxy,” elements are normally made by depositing atoms layer-by-layer onto a substrate. Epitaxy strategies additionally exist for bigger methods, reminiscent of micrometer-diameter colloids. Now Manodeep Mondal and Rajesh Ganapathy of Jawaharlal Nehru Centre for Advanced Scientific Research, India, present that interactions amongst epitaxially deposited colloids observe predictions made for atomic methods [1]. They say that the discovering may assist to enhance nanofabrication strategies.
In their experiments, Mondal and Ganapathy deposited colloids onto substrates patterned with sq. arrays of holes. The gap spacing various between substrates and differed barely from the popular colloid spacing. The duo mapped the impact of the ensuing “misfit” pressure on the expansion of the colloidal constructions utilizing microscopy measurements.
For low misfit strains, they discovered that the speed of colloid diffusion throughout the substrate remained fixed with growing construction top. They additionally discovered little distortion of underlying layers as new ones fashioned on prime. For excessive misfit strains, they discovered that the diffusion charge various considerably with construction top and that distortion results influenced how the constructions developed. For instance, for misfit strains of 4.5%, they discovered that interactions amongst colloids warped the underlying substrate, resulting in extra patchy constructions. The outcomes match predictions for atomic methods, which, being 10,000 occasions smaller than the colloids utilized in these experiments, are almost not possible to trace on this method.
“It is always a delight to directly observe and quantify an effect anticipated by theory and simulations,” Ganapathy says. “We are particularly excited about the wide range of length scales over which similar physics seems to work.”
–Katherine Wright
Katherine Wright is the Deputy Editor of Physics Magazine.
References
- M. Mondal and R. Ganapathy, “Direct measurements of surface strain-mediated lateral interactions between adsorbates in colloidal heteroepitaxy,” Phys. Rev. Lett. 129, 088003 (2022).
