TY  - JOUR
AU  - Altynbaev, E.
AU  - Siegfried, S.-A.
AU  - Moskvin, E.
AU  - Menzel, D.
AU  - Dewhurst, C.
AU  - Heinemann, A.
AU  - Feoktystov, A.
AU  - Fomicheva, L.
AU  - Tsvyashchenko, A.
AU  - Grigoriev, S.
TI  - Hidden quantum phase transition in Mn$_{1−x}$ Fe$_{x}$ Ge evidenced by small-angle neutron scattering
JO  - Physical review / B
VL  - 94
IS  - 17
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2016-06884
SP  - 174403
PY  - 2016
AB  - The magnetic system of the Mn1−xFexGe solid solution is ordered in a spiral spin structure in the whole concentration range of x∈[0÷1]. The close inspection of the small-angle neutron-scattering data reveals the quantum phase transition from the long-range ordered to short-range ordered helical structure upon increase of Fe concentration at x∈[0.25÷0.4]. The short-range order (SRO) of the helical structure is identified as a Lorentzian contribution, while long-range order is associated with the Gaussian contribution into the scattering profile function. The scenario of the quantum phase transition with x as a driving parameter is similar to the thermal phase transition in pure MnGe. The quantum nature of the SRO is proved by the temperature-independent correlation length of the helical structure at low- and intermediate-temperature ranges with remarkable decrease above certain temperature TQ. We suggest the x-dependent modification of the effective Ruderman-Kittel-Kasuya-Yosida exchange interaction within the Heisenberg model of magnetism to explain the quantum critical regime in Mn1−xFexGe.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000386656100003
DO  - DOI:10.1103/PhysRevB.94.174403
UR  - https://juser.fz-juelich.de/record/824265
ER  -