Some experimental data about the two contributions to magnetoresistance for n-type silicon crystal at 125 K

Abstract

The transverse magnetoresistance (MR) was measured versus magnetic field strengthB at different rotational anglesθ between the directions of bothB and currentI for n-type silicon crystal with charge carrier concentration of 1·8×10¹⁵cm⁻³. The direction of the current through the two samples was chosen so that the anglesϕ between the current vector and [100] crystallographic axis were 50° and 70°, respectively. These measurements were done under weak electric and magnetic fields atT=125 K. It was found that the MR exhibits two types of anomalous effects, one of them at two opposite directions ofB at differentθ, and the other at the same anglesθ, whenϕ=50° andϕ=70°. This shows that the anomalous behaviour of MR is not onlyB andθ dependent, but depends also on the current direction. Also the values ofB which are separated between the negative and positive parts of MR curves at the sameθ depend on the magnitude ofϕ. These results may be attributed to the anomalous motion of charge carriers ink-space as a result of deviation of current direction from the symmetry axis.