ACTA

Anomalous Transport Properties of Carbon-Doped EuB₆

M. Batkova^a, I. Batko^a, V. Filipov^b, K. Flachbart^a, V. Sechovský^c, N. Shitsevalova^b, E. Šantavá^d and J. Šebek^d
^aInstitute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice, Slovak Republic
^bInstitute for Problems of Material Science, NASU, 252680 Kiev, Ukraine
^cCharles University in Prague, Faculty of Mathematics and Physics, Ke Karlovu 5, 121 16 Prague, Czech Republic
^dInstitute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague, Czech Republic

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In the presented work we report electrical, magnetic and thermal properties of EuB_{6 - x}C_x single crystals with an estimated value of x ≈ 0.07. Our studies reveal an antiferromagnetic phase transition at T_N ≈ 6.7 K. Electrical resistivity at zero magnetic field shows a pronounced resistivity maximum at T_M ≈ 7 K, just above the antiferromagnetic phase transition temperature. With increasing applied magnetic field the maximum moves to lower temperature and becomes totally suppressed at the field of 9 T. Observed magnetoresistance is negative in the whole studied temperature range 2-20 K, yielding a ratio of ρ(0 T, 7 K)/ρ(9 T, 7 K) ≈ 2.5. The origin of such magnetoresistance is associated with formation of mixed magnetic structure in the system due to fluctuation of carbon concentration.

DOI: 10.12693/APhysPolA.118.893
PACS numbers: 75.30.Kz, 72.15.Gd, 75.47.Gk