No abstract

No abstract

No abstract

Field-emission current from chemical vapor deposited diamond film on molybdenum wafer has been investigated experimentally and theoretically. The Fowler–Nordheim plot exhibits three linear regimes, corresponding to low, middle, and high electric field, respectively. A potential barrier model, based on a fact that metal carbide, Mo2C, exists at the interface between diamond and substrate, is presented. In terms of this model, the expression of field-emission current from diamond on Mo has been derived. The theoretical results agree qualitatively with the experimental observation and indicate that the emission current is related to the thickness of Mo2C and diamond under low and middle electric field, however, no similar relationship is found under high field.

Magnetoresistive effects were studied in p-type heteroepitaxial diamond films with a strip or Corbino disk structure in a magnetic field ranging from 0 to 5 T. The films were grown by microwave plasma chemical vapor deposition and boron doped by cold ion implantation and rapid thermal annealing. The experimental results show that the magnetoresistance (MGR) of p-type heteroepitaxial diamond films strongly depends on the geometric form of the samples and the magnetic field. Diamond films are assumed to be an isotropic isothermal solid in which conduction is by holes from light, heavy and split-off bands. Based on the Fuchs and Sondheimer thin-film theory, considering spherical energy surfaces and mixed scattering by lattice vibrations and ionized impurities and surface, a theoretical description of the magnetoresistive effect in diamond films is presented by solving the Boltzmann transport equation in the relaxation time approximation. A relationship between the MGR and the thickness of films, magnetic field, and mobility is shown.