Structural and electrical properties of granular metal films

Abstract Granular metal films (50–200,000 A thick) were prepared by co-sputtering metals (Ni, Pt, Au) and insulators (SiO2, Al2O3), where the volume fraction of metal, x, was varied from x = 1 to x = 0.05. The materials were characterized by electron micrography, electron and X-ray diffraction, and measurements of composition, density and electrical resistivity at electric fields e up to 106 V/cm and temperatures T in the range of 1.3 to 291 K. In the metallic regime (isolated insulator particles in a metal continuum) and in the transition regime (metal and insulator particles in a metal continuum) and in the transition regime (metal and insulator labyrinth structure) the conduction is due to percolation with a percolation threshold at x⋍0.5. Tunnelling measurements on superconductor-insulator-granular metal junctions reveals that the transition from the metallic regime to the dielectric regime (10–50 A size isolated metal particles in an insulator continuum) is associated with the breaking up of a metal ...

[1]  R. Wehner,et al.  Calculation of Deposition Profiles and Compositional Analysis of Cosputtered Films , 1972 .

[2]  E. H. Snow,et al.  Fowler-Nordheim tunneling in SiO2 films , 1967 .

[3]  J. Hanak,et al.  Calculation of composition of dilute cosputtered multicomponent films , 1973 .

[4]  J. W. Robinson.  Atomic Absorption Spectroscopy , 1966 .

[5]  M. S. Abrahams,et al.  Effect of lattice expansion on the Curie temperature of granular nickel films , 1971 .

[6]  G. W. Cullen,et al.  Enhancement of superconductivity in metal films , 1966 .

[7]  D. Scalapino,et al.  Thermodynamic Properties of Electrons in Small Metal Particles , 1973 .

[8]  I. Giaever,et al.  TUNNELING INTO SUPERCONDUCTORS AT TEMPERATURES BELOW 1 K , 1962 .

[9]  R. Kubo.  Electronic Properties of Metallic Fine Particles. I. , 1962 .

[10]  S. Kirkpatrick.  Percolation and Conduction , 1973 .

[11]  C. Neugebauer.  Resistivity of cermet films containing oxides of silicon , 1970 .

[12]  R. Hill,et al.  HOPPING CONDUCTION THROUGH LOCALIZED STATES IN Nb/Al$sub 2$O$sub 3$ FILMS. , 1972 .

[13]  N. Fuschillo,et al.  Electrical Conduction and Substructure in Semicrystalline Silicon‐Monoxide‐Gold Films , 1971 .

[14]  J. Klein,et al.  Tunneling measurement of phonon spectrum in granular A1 , 1968 .

[15]  James W. Garland,et al.  EFFECT OF LATTICE DISORDER ON THE SUPERCONDUCTING TRANSITION TEMPERATURE. , 1968 .

[16]  J. Bardeen.  Tunnelling from a Many-Particle Point of View , 1961 .

[17]  R. Hill.  Electrical conduction in ultra thin metal films I. Theoretical , 1969, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[18]  J. Gittleman,et al.  Superparamagnetism and relaxation effects in granular Ni-Si O 2 and Ni- Al 2 O 3 films , 1974 .

[19]  R. W. Cohen,et al.  Superconductivity in Granular Aluminum Films , 1968 .

[20]  C. A. Neugebauer,et al.  Electrical Conduction Mechanism in Ultrathin, Evaporated Metal Films , 1962 .

[21]  N. Mott,et al.  Electronic Processes In Non-Crystalline Materials , 1940 .

[22]  I. Campbell.  Hall Effect and Resistivity Anisotropy in Ni Alloys , 1970 .

[23]  M. S. Abrahams,et al.  Transmission Electron Microscopy of Granular Nickel/SiO2 Cermet Films , 1972 .

[24]  L. Feinstein,et al.  Annealing and phase stability of tantalum films sputtered in Ar-O2 , 1974 .

[25]  Benjamin Abeles,et al.  Percolation Conductivity in W-Al 2 O 3 Granular Metal Films , 1975 .

[26]  J. Perkins.  Conduction properties and microstructure of metal/SiO cermet thin films produced by recoil atom implantation , 1972 .

[27]  A. Goodman,et al.  Photoemission of Electrons from Silicon and Gold into Silicon Dioxide , 1966 .

[28]  Rolf Landauer,et al.  The Electrical Resistance of Binary Metallic Mixtures , 1952 .

[29]  Ivar Giaever,et al.  Tunneling, Zero-Bias Anomalies, and Small Superconductors , 1969 .

[30]  H. Fritzsche.  Electronic Processes in Non-Crystalline Materials. N. F. Mott and E. A. Davis. Oxford University Press, New York, 1971. xiv, 438 pp., illus. $24. International Series of Monographs on Physics , 1972 .

[31]  J. Gittleman,et al.  Magnetic Properties of Granular Nickel Films , 1972 .

[32]  J. Lambe,et al.  Tunneling in Solids , 1973 .

[33]  A. Messiah.  Quantum Mechanics , 1961 .

[34]  P. Sheng,et al.  Voltage-Induced Tunneling Conduction in Granular Metals at Low Temperatures , 1972 .

[35]  S. Pakswer,et al.  Electrical Properties of Sputtered Au/Ta2O5 Cermet Thin Films , 1972 .

[36]  V. Weisskopf,et al.  Theoretical Nuclear Physics , 1953 .

[37]  P. Sheng,et al.  Hopping Conductivity in Granular Metals , 1973 .

[38]  M. De.  Handbuch der Physik , 1957 .

[39]  G. Shirn,et al.  CO‐SPUTTERED Au‐SiO2 CERMET FILMS , 1967 .

[40]  B. P. Watson,et al.  Conductivity in the two-dimensional-site percolation problem , 1974 .

[41]  D. Thouless.  Percolation Theory and Electrical Conductivity , 1971 .

[42]  D. Scalapino,et al.  Thermodynamic Properties of Small Superconducting Particles , 1972 .

[43]  R. W. Cohen,et al.  Critical magnetic fields of granular superconductors , 1967 .

[44]  David Adler,et al.  Electrical conductivity in disordered systems , 1973 .

[45]  Vinay Ambegaokar,et al.  Hopping Conductivity in Disordered Systems , 1971 .

[46]  B. Abeles,et al.  SUPERCONDUCTING AND SEMICONDUCTING PHASES OF GRANULAR FILMS. , 1971 .

[47]  H. Zeller.  Electrical Conductivity of One-Dimensional Conductors , 1972 .

[48]  B. Hardiman,et al.  Transport Properties, Microstructure, and Conduction Model of Cosputtered Au–SiO2 Cermet Films , 1970 .

[49]  R. Parmenter.  Characteristic parameters of a granular superconductor , 1968 .