Berlin 2012 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 32: Transport Properties I (mainly Spin Physics and Magnetic Fields)

HL 32.3: Vortrag

Dienstag, 27. März 2012, 10:30–10:45, EW 203

Magnetotransport of (Zn,Mn)Se:Cl under hydrostatic pressure — •Steve Petznick¹, Michael Hetterich², and Peter J. Klar¹ — ¹Institute of Experimental Physics I, Justus-Liebig University of Giessen, Germany — ²Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Germany

As material n-doped MBE-grown (Zn,Mn)Se:Cl on an undoped (100) GaAs substrate was used. The manganese concentration of the 1050 nm thick layer was about 2 % and the carrier concentration at room temperature was n = (4.3 ± 0.3) · 10¹⁷ cm⁻³. For the hydrostatic pressure experiments the sample was mounted in a clamp pressure cell. For different pressure values between 0 and 16.5 kbar transport measurements were obtained at different temperatures between 1.6 K and 280 K in Van der Pauw geometry and in applied magnetic fields up to 10 T.

The dependence of the magnetoresistance and the carrier concentration are shown and discussed. The splitting of the spin-up and spin-down states hinders the hopping conductivity between the donor states and results in a high magnetoresistance at low temperatures. Moreover, at high pressure a sudden decrease of the carrier concentration is observed. It is likely that this behavior is due to carrier trapping, which occurs when the band gap is in resonance with inner d-shell transitions of the Mn²⁺ ions.