2013/02/21 by A. K. Nayak, M. Nicklas, S. Chadov +4 · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevlett.110.127204
published as Phys. Rev. Lett. 110, 127204 (2013) · 5 pages, 4 figures, supplementary material included in a separate file; accepted for publication in PRL
arxiv created 2013/02/21 · arxiv updated 2013/03/21
We report a large exchange-bias (EB) effect after zero-field cooling the new tetragonal Heusler compound Mn2PtGa from the paramagnetic state. The first-principle calculation and the magnetic measurements reveal that Mn2PtGa orders ferrimagnetically with some ferromagnetic (FM) inclusions. We show that ferrimagnetic (FI) ordering is essential to isothermally induce the exchange anisotropy needed for the zero-field cooled (ZFC) EB during the virgin magnetization process. The complex magnetic behavior at low temperatures is characterized by the coexistence of a field induced irreversible magnetic behavior and a spin-glass-like phase. The field induced irreversibility originates from an unusual first-order FI to antiferromagnetic transition, whereas, the spin-glass like state forms due to the existence of anti-site disorder intrinsic to the material.