Abstract:

In this talk I will describe results of Hall effect measurements on several systems exhibiting magnetically driven percolative phase transitions. The talk will focus primarily on the semimetallic ferromagnet EuB6, in which we observed a distinctive switch in the Hall resistivity slope in the paramagnetic state. The switching fields in a broad temperature range were found to correspond to a single magnetization, which we interpret as the point of percolation for the phase-separated, magnetically-ordered, and electrically-conducting patches in the paramagnetic background [1]. We argue that this may be a general signature of electronic phase separation in materials with strong magneto-electronic correlations. We demonstrate its efficacy in anisotropically strained La2/3Ca1/3MnO3 by correlating the nonlinear features in the Hall effect with the emergence of antiferromagnetic insulating state in the materials.
[1] X. Zhang et al., PRL 103, 106602 (2009).
 
 
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