Abstract
By employing magnetization and small angle neutron scattering measurements, we have investigated the behavior of the skyrmion lattice (SKL) and the helical order in MnSi0.992Ga0.008 Our results indicate that the order of the SKL is sensitive to the orientation of an applied magnetic field with respect to the crystal lattice and to variations in the sequence of small temperature and applied magnetic field changes. The disorder caused by the substitution of the heavier element Ga for Si is sufficient to reduce the pinning of the SKL to the underlying crystalline lattice, reducing the propensity for the SKL to be aligned with the crystal lattice. This tendency is most evident when the applied field is not well oriented with respect to the high symmetry axes of the crystal resulting in disorder in the long range SKL while maintaining sharp short range (radial) order. We have also investigated the effect of substituting heavier elements into MnSi on the reorientation process of the helical domains with field cycling in MnSi0.992Ga0.008 and Mn0.985Ir0.015Si A comparison of the reorientation process in these materials with field reduction indicates that the substitution of heavier elements on either Mn or Si sites creates a higher energy barrier for the reorientation of the helical order and for the formation of domains.
| Original language | English |
|---|---|
| Article number | 024428 |
| Journal | Physical Review B |
| Volume | 99 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jan 24 2019 |
Funding
The authors acknowledge R. Jin, W. Xie, D. A. Browne for helpful discussions. We also acknowledge H. Cao for discussions and help with the crystal quality check using HB3A beamline in HFIR ORNL. This material is based upon the work supported by the U.S. Department of Energy under EPSCoR Grant No. DE-SC0012432 with additional support from the Louisiana Board of Regents. The SANS data and alignment of the samples used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. C.D. acknowledges the Department of Physics, Kennesaw State University for the resources provided during preparation of this manuscript. We also acknowledge H. Cao for discussions and help with the crystal quality check using HB3A beamline in HFIR ORNL. This material is based upon the work supported by the U.S. Department of Energy under EPSCoR Grant No. DE-SC0012432 with additional support from the Louisiana Board of Regents. The SANS data and alignment of the samples used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. C.D. acknowledges the Department of Physics, Kennesaw State University for the resources provided during preparation of this manuscript.