Field emission properties of fullerenes

Summary form only given. The term "fullerenes" is applied to a wide class of polyatomic molecules of carbon C_n, where n ≥ 60, and solids based on them. Usually, however, fullerene molecule called C₆₀, that is, a molecule consisting of sixty carbon atoms arranged on a spherical surface. The carbon atoms are located on the surface of the sphere at the vertices of pentagons (the Pentagon) and hexagons (hexagon) [1, 2,]. These closed surface structures exhibit specific properties as physical objects, and in chemical systems. Electrical, optical and mechanical properties of fullerenes indicate both the rich content of physical phenomena involving fullerenes, and the significant prospects for the use of these materials in electronics, optoelectronics and other fields. One of the most unstudied processes for fullerenes is field emission. Field electron emission-emission of free electrons from the surface of cathode during the application of high electric field [3]. This is the only form of emission, which does not require the preliminary electron excitation [4]. Before the beginning of the experiment the surface of the sample was processed into several stages. After that, the original sample was placed in a vacuum chamber. When voltage is applied between 1 and 8kV field emission pattern was not observed, and the current is also absent. After that started to investigate emission from the fragment of the sample, which was obtained by mechanical impact. Sample was placed into the vacuum system and connected according to the diode circuit. Voltage was supplied to the anode, and current in the system was measured. The following graphs were built: the voltage-current characteristics before and after experiment; the dependence of current on the time; graph in Fowler-Nordheim coordinates; the dependence of the current on tension. After conducting of experiment and obtaining the graphs, the sample surface was re-examined in a scanning electron microsc- pe. On the obtained images can be judged not only on changing the surface of the material, but also to observe the active centers of field emission. According to the results of experiment it is possible to conclude that this material can be used for preparing the planar field emission cathodes. The emission of electrons begins with the smaller anode voltage, in comparison with the other carbonic structures.