Magnetic susceptibility of doped Si nanowhiskers.

The present paper deals with studies of magnetic properties of Si(B) whiskers with large boron impurity concentration of up to 1-5% in the range of magnetic fields (0.3-4.0) kOe and temperatures of 4.2-300 K. In particular, magnetic susceptibility of whiskers has been investigated. The results obtained in the temperature range of 77-300 K have shown that magnetic susceptibility of whiskers substantially differs from that of bulk Si, which is revealed in the two significant peculiarities: (1) a substantial paramagnetic contribution into whisker magnetization and magnetic susceptibility; (2) a non-linear dependency of magnetization on magnetic field intensity. These facts indicate an existence of magnetic ordering in whiskers. The observed magnetization hysteresis at 4.2 K confirms the above supposition. Possible reasons of the observed effects have been discussed.