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Novel IV-VI diluted magnetic semiconductors doped with transition metalsтезисы доклада
- Авторы: Skipetrov E.P., Golovanov A.N., Kovalev B.B., Skipetrova L.A., Knotko A.V., Slynko E.I., Slynko V.E.
- Сборник: Abstracts 15th International Conference on Narrow Gap Systems
- Тезисы
- Год издания: 2011
- Место издания: Blacksburg, Virginia, USA
- Аннотация: In the present work we have studied crystal structure, composition and electrical properties of novel PbTe-based DMS, doped with transition elements (V, Ti, Sc). It was shown that lightly doped with vanadium samples remains p-type up to y≈0.005. Introducing of vanadium leads to the monotonous increase of resistivity ρ and Hall coefficient RH at T=4.2 K, indicating the decrease in the free hole concentration. Then p-n-conversion of the conductivity type and metal-insulator transition takes place. In the insulating phase the ρ(1/T) and RH(1/T) dependencies have an activation character due to the pinning of the Fermi level by the deep vanadium level EV, situated under the bottom of conduction band. As the tin content in the samples increases it slowly shifts from the conduction band to the middle of the gap. The diagram of vanadium level movement under the increase of the tin content x in Pb1-x-ySnxVyTe is proposed. All titanium and scandium doped alloys are n-type. Hall measurements at helium temperatures revealed that initially doping leads to the monotonous increase in the free electron concentration. Then electron concentration saturates at the level n≈6*1019 cm-3 and n≈1*1020 cm-3, respectively. These experimental results, indicating the pinning of the Fermi level by the resonant impurity levels, were used for the estimation of the titanium and scandium deep level energies in the frame of the Kane dispersion relation for IV-VI semiconductors.
- Добавил в систему: Скипетров Евгений Павлович