Transport properties, borides

Materials based on boron compounds have been explored for many decades because of their exceptional properties in respect to chemical bonding, crystal structure, and phonon and electron conduction. Especially in the field of energy conversion, electron emission, and neutron absorption, borides occupy many niches of application for which no other material can be employed. Until approximately 1980, the main interest in borides always came, however, from basic research aimed at the understanding of their electronic structure, being either responsible for the unique transport properties or the peculiarities in chemical bonding. It is, therefore, no wonder that the most information about borides was at that time created from the viewpoint of physicists and chemists. 

Transition metal borides are mainly explored for their mechanical properties. Since they exhibit metallic transport properties such as high electric and thermal conductivity with a negative temperature coefficient they are also of interest as electrode materials, for heating elements and sensors. 

In conclusion, boride ceramics are materials of high potential for use in mechanical and electric fields. Due to the stagnating materials markets, however, most research on borides is focused on the basic questions of atomic bonding and physical transport properties rather than on application-related problems. Only a few highly specialized research groups are active worldwide and promote the science rather than the technology of borides. Depending upon the economic situation and the... 

We end this review by giving references in Tables 3 and 4 to experiments on transport properties in some carbides, nitrides, and borides formed by group IV and V transition metals. The list is... 

Table 4 Some References to Transport Properties of Transition Metal Nitrides and Borides Electrical Resistivity (p) and Thermal Conductivity (k)...

H Werheit. On the electronic transport properties of boron carbide. In R Freer, ed. The Physics and Chemistry of Carbides, Nitrides and Borides. Dordrecht Kluwer, 1990, p 677. 

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