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Semiconductor Physics, Quantum Electronics & Optoelectronics. 2014. V. 17, N 4. P. 416-420.
Magnetic and magnetoresistive characteristics
of neutron-irradiated Si0.97Ge0.03 whiskers
1Institute of Nuclear Researches, NAS of Ukraine, 47, prospect Nauky, 03028 Kyiv, Ukraine Abstract. The effect of 8.6x1017 n/cm2 with fast neutron irradiation on the magnetic susceptibility of Si0.97Ge0.03 thread-like crystals (whiskers) with impurity concentration near metal-insulator junction has been studied. Significant differences have been observed in the change of magnetic susceptibility of irradiated whiskers and bulk Cz-Si. The low-temperature (4.2...40 K) changes of magnetoresistance in magnetic fields up to 14 T, caused by irradiation, have been studied. It has been established that at temperatures near 4.2 K, a significant contribution to the conductivity is made by light charge carriers of low concentration but with high mobility. The level supplying these charge carriers has the energy of ε = 2.1 meV, and with application of magnetic field it increases up to ε = 2.5 meV in approx. 10 T field. It demonstrates the fact that the reason of magnetoresistance, beside the magneto-field decrease of mobility, is the magneto-field decrease in the free carrier concentration. At temperatures approx. 40 K, conductivity is due to holes, the activation energy whereof is ε = 11.5 meV, which is practically independent of the magnetic field. Keywords:whiskers, silicon-germanium, neutron irradiation, magnetic susceptibility, magnetoresistance. Manuscript received 24.10.14; revised version received 05.09.14; accepted for publication 00.00.14; published online 00.00.14.
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