Magnetic and thermoelectric properties of BayFe4−xCoxSb12

✍ Scribed by E. Matsuoka; S. Morimoto; K. Tanaka; T. Sasakawa; T. Takabatake

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 109 KB
• Volume: 383
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2006.03.078

✦ Synopsis

We report the measurements of magnetic and thermoelectric properties of Ba y Fe 4Àx Co x Sb 12 (x ¼ 0, 1, 2, 2.5, 3). The host compound BaFe 4 Sb 12 is a nearly ferromagnetic metal. With increasing x to 2.5, the resistivity increases by one order of magnitude and both the magnetic susceptibility and electronic specific heat coefficient decrease. A diamagnetic behavior for x ¼ 2.5 indicates that the Co substitution leads to a strong decrease of the electronic density of states near the Fermi level. The thermopower for x ¼ 0 exhibits local maximum at 50 K, which disappears for xX1. A positive thermopower of 135 mV/K at 500 K for x ¼ 2.5 changes to a negative one, À120 mV/K for x ¼ 3.0. This reversal of the sign indicates that the electron carries doped with the Co substitution overcompensates for the hole carriers in this system.