STUDY OF THE FE-DOPED INTERMETALLIC URANIUM COMPOUNDS
V.V.Sikolenko1, A.M.Balagurov1, E.V.Raspopina1, V.Yu.Pomyakushin1, I.S.Lyubutin2, A.V.Gribanov3
1Joint
Institute for Nuclear Research, 141980 Dubna, Russia, sikolen@nf.jinr.ru
2Institute
of Crystallography, Moscow, Russia
3Moscow State University, Russia
Keywords: neutron diffraction, SR method,
magnetic structure, intermetallide, spin density wave, spin glass
Most of the uranium intermetallides with the ThCr2Si2 type crystal structure exhibit magnetic ordering driven by RKKY-type interaction in competition with a Kondo-type spin compensating mechanism. Some of them demonstrate spin glass like behavior of the magnetic susceptibility.
This report is devoted to review of the magnetic structures of these compounds and, in particular, to UPd2Ge2 doped with iron.
Magnetic susceptibility and magnetization studies of the solid solution U(Pd1-xFex)2Ge2 showed that magnetic properties are quite different from those of the end-member of the series UPd2Ge2 and UPd2Ge2. Even a small Fe-doping drastically changes the magnetic state of the compound. In the present systems, a small concentration of Fe impurity in UPd2Ge2 enhances the magnetic disorder, which becomes most pronounced at x = 0.02. A ferromagnetic (FM) component was found and a mixed AF-SG-FM phase was observed according to macroscopic data. According to neutron diffraction experiments the magnetic structure of UPd2Ge2 is antiferromagnetic (AF) and characterized by a longitudinal spin density wave (LSDW)
In the range of accuracy of the neutron diffraction experiment
we could only determine the shape of modulation of magnetic
structure (square or sinusoidal), but it was not possible to
follow the fluent changes on the form of modulation. Using of SR
has been proposed to clarify the details of the magnetic
structure of this compound. Another goal of present proposal was
to check presence of a mixed AF-SG-FM phase at T < TN followed from (T) and
neutron diffraction measurements. Owing to SR study of the UPd0.98Fe0.02Ge2 it was found that at
low temperatures there is AFM magnetic order. The polarization in
temperature range of incommensurate LSDW is well described by
Bessel function J0 at
the suggestion of presence the only magnetic phase which also
proved absence of FM and SG ordering in this compound.