title: X-ray diffraction method for the investigation of contacts between solid surfaces.
abstract: A coherent X-ray scattering method for investigating the formation of the contact region between two solid surfaces is presented. Diffraction of X-rays from two crossed cylindrical quartz surfaces, coated with Cr and TiO(2), revealed a total contact area of 90 +/- 10 microm. In the so-called Hertz model for two surfaces in non-adhesive contact, this value is directly related to the displacement of the surfaces and the applied external force. Values of 40 +/- 3 nm for the displacement and 24 +/- 3 mN for the force are found. The method is also useful for studying liquids in confinement.
authors.affiliation: Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland. heilke.keymeulen@psi.ch
authors.forename: H R
authors.initials: HR
authors.lastname: Keymeulen
authors.forename: T
authors.initials: T
authors.lastname: Lackner
authors.forename: A
authors.initials: A
authors.lastname: Diaz
authors.forename: B D
authors.initials: BD
authors.lastname: Patterson
authors.forename: J F
authors.initials: JF
authors.lastname: van der Veen
mesh_terms: D000465:Algorithms; D002857:Chromium / Q000032:analysis / Q000737:chemistry*; D003198:Computer Simulation; D008422:Materials Testing / Q000379:methods*; D008956:Models, Chemical; D011791:Quartz / Q000032:analysis / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission / Q000379:methods*; D013499:Surface Properties; D014025:Titanium / Q000032:analysis / Q000737:chemistry*; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D002857:Chromium; D011791:Quartz; C009495:titanium dioxide; D014025:Titanium