Graphite fiber and preparation method thereof

The invention relates to a graphite fiber and a preparation method thereof. The graphite fiber serving as a monomer fiber directly grows by adopting a vapor deposition method under the condition of no catalyst; the purity of obtained products is greater than 99.99 percent; the obtained products are straight and filamentous in appearance, the diameter range is 0.1 to 50mu m and the length range is 3 to 100mm; the products are generally parallel to one another; a hemispherical sealing cover is arranged at the top of each product and the interior of the fiber is solid; Raman spectrum shows that the intensity of a G peak is greater than that of a D peak in the graphite fiber; the graphite fiber has a metallic luster under the irradiation of visible light, and the resistivity of the graphite fiber is equivalent to that of graphite. The graphite fiber uses a quartz plate as a substrate, adopts argon and hydrogen as carrier gases, selects methane as a carbon source, and is prepared by cleaning the substrate, chargin