magnetisation and electron spin resonance studies of tetrahedral amorphous carbon

MAGNETISATION AND ELECTRON SPIN RESONANCE STUDIES OF TETRAHEDRAL AMORPHOUS CARBON

The magnetisation and electron spin resonance (ESR) spectrum of two specimens of tetrahedral amorphous carbon (ta-C), deposited from a filtered cathodic arc, were measured over a wide temperature range. The magnetisation was found to consist of superparamagnetic, paramagnetic and diamagnetic contributions. The superparamagnetic contribution resembled that recently found in carbon prepared from ...

Electron field emission properties of tetrahedral amorphous carbon films

The electron field emission of tetrahedral amorphous carbon ~ta-C! films deposited by filtered cathodic vacuum arc is reported. The ta-C films were found to have a threshold field ranging from 18 to 28 V mm, depending on the sp content. The nitrogenated ta-C ~ta-C:N! films show a lower threshold field of 12 V mm as compared to the ta-C films. The threshold field appears to be dependent on the f...

Photomodulated electron-spin resonance in amorphous silicon

Electron field emission from surface treated tetrahedral amorphous carbon films

The electron field emission properties of tetrahedral amorphous carbon thin films deposited using a filtered cathodic vacuum arc system have improved as a result of surface treatment with H, O, and Ar ions. The limiting factor of the emission process does not appear to be only the front surface of the films. The improvement in the emission after ion beam treatment appears to be independent of t...

uv Studies of Tetrahedral Bonding in Diamondlike Amorphous Carbon

We report ultraviolet (uv) Raman scattering studies of hydrogen-free, diamondlike amorphous carbon thin films with a wide range of tetrahedral bonding. The uv Raman spectra are shown to provide direct evidence for the presence of sp-bonded C atoms in these materials. The experimental results are found to be in excellent agreement with theoretical predictions and contribute to an improved unders...

Dynamic roughening of tetrahedral amorphous carbon.

The roughness of tetrahedral amorphous carbon (ta-C) films grown at room temperature is measured as a function of film thickness by atomic force microscopy, to extract roughness and growth exponents of alpha approximately 0.39 and beta approximately 0-0.1, respectively. This extremely small growth exponent shows that some form of surface diffusion and relaxation operates at a homologous tempera...