Diamond is the most suitable material for many experimental methods in nanoprobe microscopy and materials testing. The extreme hardness, the high Young’s modulus, the inert nature of the surface, and the electrical conductivity obtained through doping make this material particularly attractive. We have coated silicon atomic force microscope (AFM) levers with thin (100 nm) doped diamond layers by chemical vapor deposition (CVD). A continuous diamond coating was obtained, resulting in tips with 100–200 nm radii. Owing to their electrical conductivity, these tips were found to be adequate for conducting AFM and scanning tunneling microscope applications, some of which are briefly discussed and reviewed in this article. We have also demonstrated CVD diamond tips, microfabricated in a controlled fashion, that have a 20 nm apex radius. These tips are particularly promising for nanomechanics and general AFM use.

P-PdH(D)063 specimens had been quenched across the 50-K anomaly and/or bombarded with electrons of 0.35 -0.8 MeV energy at 20 K. They exhibited after each treatment a residualresistivity decrease,hp, which annealed upon heating in the anomaly region. A kinetic analysis of the recovery process yielded an activation energy for H-defect migration of E (H, D) =50%15 meV for a first-order reaction. An investigation of the isotope-dependent radiation-inducedbp;"asa function of the electron energy led, by fitting theoretical collision cross sections, to a displacement threshold assimilated with a binding energy of hydrogen in its sublattice, Eb -0.01 eV, and to a defect resistivity, pdd = -6 pQ cm/unit concentration. The proposed defect configuration is occupational disorder in the hydrogen-vacancy sublattice, created by site interchange of H atoms with vacant octahedral sites of the Pd lattice, This leads to an effective redistribution of the Ni"Mo ( n = 1 -4) type rnicrodomains (Ni equivalent to H, Mo equivalent to H vacancy) as observed by neutron scattering in the anomaly region, by locally forming Ni"+lMo-type cells of different symmetry.

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The isotherms of very thin PdHx films (60 Å<d<600 Å) have been determined below room temperature by equilibrium potential measurements. One finds that the critical temperature Tc is lowered when the film thickness decreases: for the 60-Å film Tc would be near 173 K. This marked drop of Tc is attributed to clamping effects of the sample on the substrate, which decreases the effective H–H interaction and favors short-range coherency effects.