Temperature Dependence of Galvanomagnetic Properties of Graphite between 4.2 K and 298 K

Abstract

By means of a phase-sensitive detection technique, the basal-plane galvanomagneticp roperties of highly crystalline graphite have precisely been investigated as functions of temperature ( T ) down to 4.2 K and of magnetic field intensity ( H ) up to 6.1 kOe. The average mobility of majority carriers has been found to vary in proportion to T -1.6 in the range 40 K to 80 K and to T -1.2 above it, while a saturating trend due to the defect scattering comes about below it. The Hall coefficient is highly dependent on H at T <200 K, the field dependence being nearly in agreement with Soule's observation at 77 K and 4.2 K. The zero-field Hall coefficient behaves in a fashion consistent with Ono-Sugihara's theory over the most part of temperature range examined, but deviates remarkably at T <30 K. The magnetoconductivity tensors are determined as functions of T and H ; both diagonal and off-diagonal components depend considerably on the sample quality especially at T <100 K. Discussions are given with reference to the transport mechanisms.