Giant and robust topological Hall effect in Chiral Magnet Co7Zn8Mn5

Abstract: Recently, \b{eta}-Mn-type Co-Zn-Mn alloys have gained particular attentions as a new class of chiral magnets hosting skyrmion phase. In this work, a giant topological Hall effect(THE)is observed during the wide temperature range below 220 K in the chiral magnet Co7Zn8Mn5. The maximum topological Hall resistivity, -2.1 {\mu}{\Omega} cm, is obtained at 10 K. Moreover, the observed THE effect persists up to Tc, which is mainly derived from the noncoplanar spin structure with scalar spin chirality. In contrast, the formation of skyrmion phase is substantiated at the temperature interval slightly below Tc by adopting the magnetization and ac-susceptibility. Further, the possible signal of skyrmion-conical coexisting phase is found based on the out-of-phase component in magnetoelastic measurements. These results strongly suggest the chiral magnet Co7Zn8Mn5 compound should be an excellent candidate to study the topological magnetic properties and high temperature skyrmions.