Physical properties of the R3Pt23Si11 compounds with volatile rare earth: Sm, Eu, Tm and Yb

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:378

Article

Opagiste, C.^1,2  Barbier, C.^1,2  Haettel, R.^1,2  Galera, R. M.^1,2 

[1] Univ Grenoble Alpes, Inst NEEL, F-38042 Grenoble, France

[2] CNRS, Inst NEEL, F-38042 Grenoble, France

关键词: Rare-earth intermetallics;    Ferromagnetism;    Van Vleck paramagnetism;    Diamagnetism;   

DOI  :  10.1016/j.jmmm.2014.11.070

来源: Elsevier

【 摘 要 】

The new R3Pt23Si11 series, where R is a rare earth, has been completed with the synthesis of three new compounds with volatile rare earth: R=Eu. Sm, and Tm. The studies of their physical properties have been performed along with those of the Yb3Pt23S11 compound. The X-ray powder diffraction patterns confirm that they all crystallize in the same face-centered cubic structure, space group Fm (3) over barm, as the rest of the series. The refinements of the diffraction patterns show an anomalously high lattice parameter in Eu3Pt23Si11 and Yb3Pt23Si11, indicating a divalent valence state for Eu and Yb. This 2+ valence state for Eu and Yb ions is confirmed by the magnetic measurements. A ferromagnetic order is observed at T-C=5.54 +/- 0.07 K and 10.12 +/- 0.07 K in Eu3Pt23Si11 and Sm3Pt23Si11 respectively. In Tm3Pt23Si11 no magnetic order is found down to 0.36 K while Yb3Pt23Si11 reveals a diamagnetic behavior. At low temperatures the spontaneous moment, M-s, in Eu3Pt23Si11 is in agreement with a L=0, S=7/2 state for the Eu2+ ion. On the contrary in Sm3Pt23Si11, M-s, is far below the 0.714 mu(B) expected for the saturated moment of the SM3+ in the J=7/2 ground state multiplet. (C) 2014 Elsevier B.V. All rights reserved.

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