%0 Journal Article
%A Altynbaev, E.
%A Siegfried, S.-A.
%A Moskvin, E.
%A Menzel, D.
%A Dewhurst, C.
%A Heinemann, A.
%A Feoktystov, A.
%A Fomicheva, L.
%A Tsvyashchenko, A.
%A Grigoriev, S.
%T Hidden quantum phase transition in Mn$_{1−x}$ Fe$_{x}$ Ge evidenced by small-angle neutron scattering
%J Physical review / B
%V 94
%N 17
%@ 2469-9950
%C Woodbury, NY
%I Inst.
%M FZJ-2016-06884
%P 174403
%D 2016
%X 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.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000386656100003
%R 10.1103/PhysRevB.94.174403
%U https://juser.fz-juelich.de/record/824265