Low temperature ferromagnetism in the new diluted magnetic semiconductor p-Bi2-xFexTe3

Single crystals of the new diluted magnetic semiconductor of p-Bi2-xFexTe3 (0≤x≤0.08) and n-Bi2-xFexSe3 (0≤x≤0.06) have been synthesized. The ferromagnetic phase was found at a temperature Tc which increases with Fe content x up to Tc=12 K for x=0.08 in p-Bi2-xFexTe3. The easy-axis for magnetization is parallel to the C3 crystallographic axis. In n-type samples Bi2-xFexSe3 ferromagnetic transition was not found down to 2 K. The de Haas-van Alphen effect was observed in p-Bi2-xFexTe3. The Shubnikov-de Haas (SdH) effect was investigated in both types of samples. Frequency of oscillation decreases with Fe doping in p-Bi2-xFexTe3 and increases in n-Bi2-xFexSe3. Thus Fe atoms exhibit donor properties