TY  - JOUR
AU  - Loewenhaupt, M.
AU  - Geselbracht, P.
AU  - Faulhaber, E.
AU  - Rotter, M.
AU  - Doerr, M.
AU  - Schmalzl, K.
AU  - Schneidewind, A.
TI  - Field Dependence of the Magnetic Propagation Vector of the Heavy Fermion Compound CeCu2Ge2 Studied by Neutron Diffraction
JO  - Physics procedia
VL  - 75
SN  - 1875-3892
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - FZJ-2016-00393
SP  - 230 - 237
PY  - 2015
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000381129300032
DO  - DOI:10.1016/j.phpro.2015.12.028
UR  - https://juser.fz-juelich.de/record/280626
ER  -