Ferromagnetism in novel compounds of the R3Pt23Si11 series with heavy rare earth: Gd, Tb, Dy, Ho and Er

• Published in: Journal of magnetism and magnetic materials 2014-05, Vol.357, p.13-17
• Main Authors: Opagiste, C., Galéra, R.M.
• Format: Article
• Language: English
• Subjects: Condensed Matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Domain effects, magnetization curves, and hysteresis; Entropy; Exact sciences and technology; Ferromagnetism; Heat-capacity; Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Magnetization curves, magnetization reversal, hysteresis, barkhausen and related effects; Magnetocaloric effect, magnetic cooling; Physics; Rare-earth intermetallics; Strongly Correlated Electrons
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2014.01.010

We have synthesized new compounds of the R3Pt23Si11 series with R=Gd, Tb, Dy, Ho and Er, and studied their magnetic and thermodynamic properties. X-ray powder diffraction characterization confirms that all these compounds crystallize in the same face-centered cubic structure, space group Fm3¯m, as Ce3Pt23Si11. They all present a ferromagnetic order at low temperatures. The Curie temperatures range between 42±1K and 3.39±0.05K for Gd3Pt23Si11 and Er3Pt23Si11 respectively. For all compounds the value of the spontaneous moment at 2K is far below the value expected for the saturated moment of the R3+ ions, except for the Gd compound. The estimations of the magnetic entropy at TC remain smaller than the full entropy of the fundamental multiplet, Rln(2J+1). Both reductions, of the moment and of the magnetic entropy, are ascribed to the crystal field effects. In the paramagnetic phase the thermal variation of the suceptibilities follows a Curie–Weiss law with Curie constants in good agreement with the theoretical values.