Electron effective mass in n-type electron-induced ferromagnetic semiconductor (In,Fe)As: Evidence of conduction band transport

The electron effective mass (m*) in n-type carrier-induced ferromagnetic semiconductor (In,Fe)As was estimated by using the thermoelectric Seebeck effect. It was found that m* is 0.03 similar to 0.17m(0) depending on the electron concentration, where m(0) is the free electron mass. These values are similar to those of electrons in the conduction band of n(+) InAs. The Fermi level E-F in (In,Fe)As is located at least 0.15 eV above the conduction band bottom. Our results indicate that electron carriers in (In,Fe)As reside in the conduction band, rather than in a hypothetical Fe-related itinerant impurity band. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4772630]