%0 Journal Article
%A Loewenhaupt, M.
%A Geselbracht, P.
%A Faulhaber, E.
%A Rotter, M.
%A Doerr, M.
%A Schmalzl, K.
%A Schneidewind, A.
%T Field Dependence of the Magnetic Propagation Vector of the Heavy Fermion Compound CeCu2Ge2 Studied by Neutron Diffraction
%J Physics procedia
%V 75
%@ 1875-3892
%C Amsterdam [u.a.]
%I Elsevier
%M FZJ-2016-00393
%P 230 - 237
%D 2015
%X CeCu2Ge2, the counterpart of the heavy-fermion superconductor CeCu2Si2, exhibits an in-commensurate antiferromagnetically long-range ordered ground state with τ = (0.28 0.28 0.54) below TN = 4.15K. The magnetism is strongly affected by a Kondo screening of the Ce 4f-moments by conduction electrons. The similar energy scale of both, Kondo and exchange interactions, results in a complex magnetic phase diagram and gives rise to potential quantum critical phenomena at very low temperatures. We present elastic neutron diffraction data obtained on a CeCu2Ge2 single crystal employing the cold triple axis spectrometer PANDA at MLZ and the diffractometer D23 at ILL.The field dependence of the magnetic propagation vector was measured at T ≤ 400 mK in the [110]/[001] plane with vertical magnetic fields applied along [1̄10]. We observe a low-field incommensurate magnetic phase AF1, a first order phase transition around 7.8 T with the coexistence of two phases AF1 and AF2 with slightly different propagation vectors, the disappearance of AF1 at 8 T and the existence of AF2 up to 12 T with a possible modification at 10 T. At 12.6 T, yet still well below the value of 26 T of the saturation for magnetic fields in [110] direction, the AF2-type magnetic order is lost and magnetic intensities are not to be found at incommensurate positions in the [110]/[001] plane any more. These new results contradict a previously suggested scenario with a QCP located at 8 T and contribute new information to the B − T phase diagram of CeCu2Ge2 in [110] direction.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000381129300032
%R 10.1016/j.phpro.2015.12.028
%U https://juser.fz-juelich.de/record/280626