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theoretical.study.for.several.years,.in.addition.to.the.focus.on.other.interfaces.incor-
porating. a. liquid. metal. component.. A. major. reason. for. this. is. that. these. surfaces.
display. properties. that. are. more. complex. than. those. of. the. surfaces. of. ionic. and.
dielectric. liquids.. The. atomic. structure. of. the. surface. of. a. simple. dielectric. liquid.
is. generally. believed. to. be. relatively. straightforward,. exempliied. by. a. monotonic.
decrease.in.the.transverse.density.proile.from.the.bulk.liquid.density.to.the.vapor.
density..The.situation.is.more.complex.across.the.transition.zone.of.a.liquid.metal;.
this. is. particularly. apparent. in. the. density. proile,. which. displays. oscillations. on.
the. liquid. side. of. the. interface. (see. Figure. 5.1).. A. density. proile. containing. such.
oscillations.is.indicative.of.the.formation.of.atomic.layers..In.the.liquid,.where.the.
atoms. undergo. diffusive. motion,. the. layers. will. exist. as. preferential. regions. with.
higher.or.lower.densities.(corresponding.respectively.to.maxima.and.minima.in.the.
density.proile)..At.a.fundamental.level,.the.differences.seen.between.the.structures.
of. the. surfaces. of. liquid. dielectrics. and. liquid. metals. relect. the. behaviors. of. the.
microscopic.interactions.across.the.different.interfaces..In.the.case.of.a.dielectric,.
the.nature.of.the.interatomic.interactions.may.not.need.to.change.a.great.deal.across.
the.interface,.for.instance,.being.van.der.Waals.bonding.in.both.the.liquid.and.vapor.
phases. of. the. material. [3].. In. the. liquid. metal. case,. there. has. to. be. a. substantial.
Localized electrons
van der Waals bonding
Vapor
Vapor
Liquid
Liquid
Delocalized electrons
metallic bonding
Dielectric
Metal
FIGURE 5.1
Comparison.between.the.free.surfaces.of.a.liquid.dielectric.(left).and.a.liq-
uid.metal.(right),.with.the.types.of.interatomic.interactions.in.effect.in.the.different.regions.
indicated.
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