COOPERATIVE TRANSPORT PHENOMENA IN PHASE-SEPARATED DEGENERATE ANTIFERROMAGNETIC SEMICONDUCTORS

The response to a strong electric field of degenerate antiferromagneti c semiconductors EuTe, which are spontaneously separated into antiferr omagnetic and ferromagnetic phases, is investigated. While in weak fie lds their response is ohmic, in strong fields a sequence of very high peaks appears against the ohmic-type background, beginning at a certai n threshold field strength. Their spacing decreases with increasing fi eld strength. These peaks can be explained by the cooperative motion o f charged ferromagnetic microregions inside the antiferromagnetic host .