Giant magnetoresistive effects in antiferomagnetic semiconductors BaMn<sub>2</sub>Pn<sub>2</sub> (Pn = As, Sb, Bi)
ORAL
Abstract
In this talk, we report the intriguing giant negative magnetoresistive effects observed in BaMn2Pn2 compounds, in which Pn stands for the pnictogens As, Sb, and Bi. These materials adopts identical (122) crystallographic and G-type antiferromagnetic structures and can be very interesting from the view point of symmetry. Here the magnetic point group 4’/m’mm’ directly suggests the existence of a diagonal dissipative magnetoelectric effect confined in the ab plane of the crystals. Importantly, by changing the Pn elements, both spin-orbit coupling and pd hybridization can be tuned without disturbing the symmetry.
We will describe the first systematic observations on the magnetotransport properties of BaMn2Pn2 compounds under a wide range of magnetic fields (B) and temperatures (T). All three compounds show very large negative magnetoresistance (MR) with complex dependencies on B and T. When Pn elements were changed from As to Bi, the observed MR changed systematically in both its magnitude and B-dependence. In the extreme B regime, the MR of BaMn2Bi2 becomes the largest among the BaMn2Pn2’s in the smallest B-range.
We will describe the first systematic observations on the magnetotransport properties of BaMn2Pn2 compounds under a wide range of magnetic fields (B) and temperatures (T). All three compounds show very large negative magnetoresistance (MR) with complex dependencies on B and T. When Pn elements were changed from As to Bi, the observed MR changed systematically in both its magnitude and B-dependence. In the extreme B regime, the MR of BaMn2Bi2 becomes the largest among the BaMn2Pn2’s in the smallest B-range.
–
Presenters
-
Katsumi Tanigaki
- Advance Institute for Material Research & Department of Physics, Graduate School of Science, Tohoku University