Influence of the Crystal Field on Dy3+ Ions in DyM2Si2 Compounds as Revealed by Investigations of Their Magnetic Properties and Nuclear Hyperfine Interactions
The crystal field interaction exhibits a pronounced effect on the nuclear hyperfine coupling in the tetragonal dysprosium compounds DyM2Si2 (M=Mn, Re, Co, Ni, Cu)1. The arrangement of atoms surrounding the dysprosium ion is shown in Fig. 1. The crystalline electric field influence is also visible in the results of the bulk magnetic measurements. Fig. 2 shows the magnetization and the inverse susceptibility for DyFe2Si2 and DyCo2Si2. The latter compound undergoes an antiferromagnetic transition at TN = 19 K while the former remains paramagnetic down to helium temperatures. The influence of the crystal field is clearly reflected in the temperature dependence of the inverse molar susceptibility of DyNi2Si2 (Fig. 3), since this compound stays paramagnetic at least down to 4.2 K. The susceptibility of DyCu2Si2 obeys a Curie-Weiss law with an effective moment of 10.3 μB (Fig. 3) and the compound orders antiferromagnetically at TN = 11 K. In Fig. 4 we see the dependence of the magnetization of DyCu2Si2 at 4.2 K upon the application of a magnetic field. This indicates a spin reorientation process being forced by the external field. The effect vanishes close to the Néel temperature (see the 11 K curve in Fig. 4). The less smeared spin reorientation behavior for another polycrystalline sample of DyCo2Si2 can also be seen.
KeywordsCrystal Field Neel Temperature Spin Reorientation Antiferromagnetic Transition Nuclear Hyperfine
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- 1.E.A. Görlich, A.Z. Hrynkiewicz, R. Kmiec, K. Tomaia (tobe published).Google Scholar