Autor: |
M. Ohkuma, M. Mito, M. Pardo, Y. Kousaka, S. Iwasaki, K. Ohishi, J. Akimitsu, K. Inoue, V. Laliena, J. Campo |
Jazyk: |
angličtina |
Rok vydání: |
2022 |
Předmět: |
|
Zdroj: |
APL Materials, Vol 10, Iss 4, Pp 041104-041104-6 (2022) |
Druh dokumentu: |
article |
ISSN: |
2166-532X |
DOI: |
10.1063/5.0084342 |
Popis: |
It is well known that the archetype chiral magnet MnSi stabilizes a skyrmion lattice, termed “A-phase,” in a narrow temperature range in the vicinity of the paramagnetic boundary around Tc ∼ 29 K and Hc ∼ 2 kOe. Recently, it has been predicted that at much lower temperatures below Tc, the conical helicoid and the forced ferromagnetic (FFM) states could be separated by a new “unknown state.” In order to detect this “unknown state,” we explored the phase diagram of MnSi oriented single crystals as a function of the d.c. magnetic field (H⃗dc) and the temperature (T) by using a.c. magnetization measurements. For H⃗dc∥ 〈111〉, we observed a new region, termed “B-phase,” in the magnetic phase diagram, characterized by a flat-valley-like anomaly on the in-phase component of the a.c. magnetization (m′), over 3.5 ≤ Hdc ≤ 6.2 kOe just below the low temperature (T < 6 K) FFM boundary. The observed frequency independence over 0.3–1000 Hz and the absence of any measurable absorption in the a.c. magnetization (m″) in the “B-phase” suggest a static nature. The “B-phase” was not observed for either H⃗dc∥ 〈100〉 or 〈110〉, revealing that the magnetic anisotropy could play a role in the stabilization of the phase. The “B-phase” could be compatible with the theoretical predictions if the new magnetic state is supposedly related with a relative reorientation of the four helices in MnSi. |
Databáze: |
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