TY - JOUR
T1 - Evolution of helimagnetic correlations when approaching the quantum critical point of Mn1-xFexSi
AU - Pappas, C.
AU - Leonov, A.O.
AU - Bannenberg, L.J.
AU - Fouquet, P
AU - Wolf, T.
AU - Weber, F
PY - 2021/1/8
Y1 - 2021/1/8
N2 - We present a comprehensive investigation of the evolution of helimagnetic correlations in Mn1−xFexSi with increasing doping. By combining polarized neutron scattering and high resolution neutron spin echo spectroscopy we investigate three samples with x = 0.09, 0.11, and 0.14, i.e., with compositions on both sides of the concentration x∗∼0.11 where the helimagnetic Bragg peaks disappear and between x∗ and the quantum critical concentration xC∼0.17, where TC vanishes. We find that the abrupt disappearance of the long range helical periodicity at x∗ does not affect the precursor fluctuating correlations. These build up with decreasing temperature in a similar way as for the parent compound MnSi. Also the dynamics bears strong similarities to MnSi. The analysis of our results indicates that frustration, possibly due to achiral Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions, increases with increasing Fe doping. We argue that this effect explains both the expansion of the precursor phase with increasing x and the abrupt disappearance of long range helimagnetic periodicity at x∗.
AB - We present a comprehensive investigation of the evolution of helimagnetic correlations in Mn1−xFexSi with increasing doping. By combining polarized neutron scattering and high resolution neutron spin echo spectroscopy we investigate three samples with x = 0.09, 0.11, and 0.14, i.e., with compositions on both sides of the concentration x∗∼0.11 where the helimagnetic Bragg peaks disappear and between x∗ and the quantum critical concentration xC∼0.17, where TC vanishes. We find that the abrupt disappearance of the long range helical periodicity at x∗ does not affect the precursor fluctuating correlations. These build up with decreasing temperature in a similar way as for the parent compound MnSi. Also the dynamics bears strong similarities to MnSi. The analysis of our results indicates that frustration, possibly due to achiral Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions, increases with increasing Fe doping. We argue that this effect explains both the expansion of the precursor phase with increasing x and the abrupt disappearance of long range helimagnetic periodicity at x∗.
UR - http://www.scopus.com/inward/record.url?scp=85112107996&partnerID=8YFLogxK
U2 - 10.1103/PhysRevResearch.3.013019
DO - 10.1103/PhysRevResearch.3.013019
M3 - Article
SN - 2643-1564
VL - 3
SP - 1
EP - 7
JO - Physical Review Research
JF - Physical Review Research
IS - 1
M1 - 013019
ER -