Abstract
A measurement of the hole density in the ferromagnetic semiconductor Ga1-xMnxAs is notoriously difficult using standard transport techniques due to the dominance of the anomalous Hall effect. Here we report a spectroscopic measurement of the hole density in four Ga1-xMnxAs samples (x = 0, 0.038, 0.061, and 0.083) at room temperature using a Raman-scattering intensity analysis of the coupled plasmon-LO-phonon mode and the unscreened LO phonon. The unscreened LO-phonon frequency linearly decreases as the Mn concentration increases up to 8.3%. The hole density determined from the Raman scattering shows a monotonic increase with increasing x for x≤0.083, exhibiting a direct correlation to the observed Tc. The optical technique reported here provides an unambiguous means of determining the hole density in this important class of "spintronic" semiconductor materials.
Original language | English (US) |
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Article number | 033202 |
Pages (from-to) | 332021-332024 |
Number of pages | 4 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 66 |
Issue number | 3 |
DOIs | |
State | Published - Jul 15 2002 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics