Onset of a skyrmion phase by chemical substitution in MnGe-based chiral magnets

E. Altynbaev (1) , N. Martin (2) , A. Heinemann (3) , L. Fomicheva (4) , A. Tsvyashchenko (4) , I. Mirebeau (2) , S. Grigoriev (1)

1 NRC KI - National Research Center "Kurchatov Institute"
2 LLB - UMR 12 - Laboratoire Léon Brillouin
3 GKSS - Helmholtz-Zentrum Geesthacht
4 HPPI - Institute for High Pressure Physics of the RAS

We study the evolution of the magnetic phase diagram of Mn 1−x Fe x Ge alloys with concentration x (0 x 0.3) by small-angle neutron scattering. We unambiguously observe the absence of a skyrmion (Sk) lattice (or A phase) in bulk MnGe and its onset under a small Mn/Fe substitution. The A phase is there endowed with extremely small Sks, potentially resulting in a high density, and is stabilized within a very large temperature region and a field range which scales with the Fe concentration. Our findings highlight the possibility to fine tune the properties of skyrmion lattices by means of chemical doping.

Domaines: Physique [physics]; Matière Condensée [cond-mat]

E. Altynbaev, N. Martin, A. Heinemann, L. Fomicheva, A. Tsvyashchenko, et al.. Onset of a skyrmion phase by chemical substitution in MnGe-based chiral magnets. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2020, 101 (10), ⟨10.1103/PhysRevB.101.100404⟩. ⟨hal-02508114⟩