J. Phys. D: Appl. Phys. 50, 145301 (2017)
J. Barzola-Quiquia, T. Lühmann, R. Wunderlich, M. Stiller, M. Zoraghi, J. Meijer, P. Esquinazi, J. Böttner, and I. Estrela-Lopis
Abstract
Micrometer width and nanometer thick wires with different shapes were produced ~3 μm below the surface of a diamond crystal using a microbeam of He+ ions with 1.8 MeV energy. Initial samples are amorphous and after annealing at T ~ 1475 K, the wires crystallized into graphite-like structures, according to confocal Raman spectroscopy measurements. The electrical resistivity at room temperature is only one order of magnitude larger than the in-plane resistivity of highly oriented pyrolytic bulk graphite and shows a small resistivity ratio (ρ(2K)/ρ(315K) ~ 1.275). A small negative magnetoresistance below T = 200 K was measured and can be well understood taking spin-dependent scattering processes into account. The used method provides the means to design and produce millimeter to micrometer sized conducting circuits with arbitrary shape embedded in a diamond matrix.