Formation of metallic magnetic clusters in a Kondo-lattice metal: Evidence from an optical study

• Published in: Scientific reports Vol. 2; no. 1; p. 890
• Main Authors: Kovaleva, N. N., Kugel, K. I., Bazhenov, A. V., Fursova, T. N., Löser, W., Xu, Y., Behr, G., Kusmartsev, F. V.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 27-11-2012; Nature Publishing Group
• Subjects: 639/301; 639/301/119; 639/766/25; 639/766/483; Conduction; Conductivity; Humanities and Social Sciences; Low temperature; Magnetism; Metals; multidisciplinary; Science
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep00890

Magnetic materials are usually divided into two classes: those with localised magnetic moments and those with itinerant charge carriers. We present a comprehensive experimental (spectroscopic ellipsomerty) and theoretical study to demonstrate that these two types of magnetism do not only coexist but complement each other in the Kondo-lattice metal, Tb
2
PdSi
3
. In this material the itinerant charge carriers interact with large localised magnetic moments of Tb(4f) states, forming complex magnetic lattices at low temperatures, which we associate with self-organisation of magnetic clusters. The formation of magnetic clusters results in low-energy optical spectral weight shifts, which correspond to opening of the pseudogap in the conduction band of the itinerant charge carriers and development of the low- and high-spin intersite electronic transitions. This phenomenon, driven by self-trapping of electrons by magnetic fluctuations, could be common in correlated metals, including besides Kondo-lattice metals, Fe-based and cuprate superconductors.