Transport and magnetic properties of carbon doped EuB₆

Abstract

We report resistivity, magnetoresistance, Hall effect, specific heat, and magnetic measurements on small single crystals having the nominal compositions EuB5.97C0.03(ao = 4.183 Å) and EuB 5.95C0.05(ao = 4.182 Å). We find that these materials are degenerate semiconductors in which both the carrier concentration and antiferromagnetic interactions increase with increasing carbon content. These results agree qualitatively with earlier work and confirm that pressure and chemical doping have opposite effects on the magnetic behavior of EuB6.