Study of the Kondo effect and intrinsic electrical conduction in titanium diboride

• Published in: Journal of applied physics 1984-10, Vol.56 (8), p.2295-2302
• Main Authors: WILLIAMS, R. K, BECHER, P. F, FINCH, C. B
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity phenomena in semiconductors and insulators; Electronic transport in condensed matter; Exact sciences and technology; High-field and nonlinear effects; Physics
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.334263

Electrical resistivity data for seven dense polycrystalline TiB2 samples are reported. The data, which extend from 4.2 to 300 K, all show resistivity minima in the 34 – 47 K range and this is attributed to the Kondo effect. Although the residual resistivity values varied by only a factor of about 2, the strength of the Kondo effect changed by a factor of 15. These differences are related to the effects of processing variables. The ideal resistivity of TiB2 was calculated from the measurements and was found to vary about as T5 at low temperatures. These values can be adequately described by the Bloch–Grüneisen equation, and the characteristic temperature obtained from resistivity, 720 K, is in reasonably good agreement with the Debye temperature from specific heat measurements. A comparison of the electronic scattering part of the Bloch–Grüneisen constant shows that TiB2 is a somewhat better conductor than Ti and the electronic band structures of ZrB2 and Zr help to explain this difference.