Anomalous Hall- and magneto- resistances on Cr-doped Ge in high magnetic fields observed up to room temperature

Ge1-xCrx films grown by MBE show quite large magneto-transport effects in the temperature range up to the room temperature. Especially, Hall resistance in DC- fields up to 10 Tesla and magneto-resistances in pulsed fields up to 60 Tesla show significant nonlinear field dependence. The magnetic field effects on the transport properties are usually quite small in conducting materials and phonon plays main role above liq. N2 temperature. ESR measurements suggest that antiferromagnetism up to TNaround 70 K exists and the critical spin fluctuation might affects to the nonlinear field dependence in magneto-transport phenomena in high temperatures