Electrical properties of biomorphic SiC ceramics and SiC/Si composites fabricated from medium density fiberboard
|Author||Orlova, T. S.
Popov, V. V.
Quispe Cancapa, José Javier
Hernández Maldonado, David
Enrique Magariño, María Esther
Varela Feria, Francisco Manuel
Ramírez de Arellano López, Antonio
Martínez Fernández, Julián
|Department||Universidad de Sevilla. Departamento de Física de la Materia Condensada|
|Abstract||A study has been made of the dependences of the electrical resistivity and the Hall coefficient on the temperature in the range 1.8–1300 K and on magnetic fields of up to 28 kOe for the biomorphic SiC/Si (MDF-SiC/Si) ...
A study has been made of the dependences of the electrical resistivity and the Hall coefficient on the temperature in the range 1.8–1300 K and on magnetic fields of up to 28 kOe for the biomorphic SiC/Si (MDF-SiC/Si) composite and biomorphic porous SiC (MDF-SiC) based upon artificial cellulosic precursor (MDF – medium density fiberboards). It has been shown that electric transport in MDF-SiC is effected by carriers of n-type with a high concentration of ∼1020 cm−3 and a low mobility of ∼0.4 cm2 V−1 s−1. The specific features in the conductivity of MDF-SiC are explained by quantum effects arising in disordered systems and requiring quantum corrections to conductivity. The TEM studies confirmed the presence of disordering structural features (nanocrystalline regions) in MDF-SiC. The conductivity of MDF-SiC/Si composite originates primarily from Si component in the temperature range 1.8–500 K and since ∼500 to 600 K the contribution of MDF-SiC matrix becomes dominant.