Anomalous electronic transport and magnetic instability in Eu1−xLaxB6 (x=0.0, 0.1, 0.2, and 0.3)

Abstract

We investigated the anomalous magnetic and transport properties for Eu1−xLaxB6 (x=0.0, 0.1, 0.2, and 0.3) series compounds. From the magnetization measurements, it was found that the ferromagnetic state with Tc≈15K for EuB6 evolves to an antiferromagnetic-like state with Néel temperature TN≈8.5K for Eu1−xLaxB6 (x=0.3). Frustrated unstable magnetic state is induced by a small doping of La in Eu1−xLaxB6 (x=0.1 and 0.2). Interestingly, the gap-like increase of resistivity ρ(T) appears at low temperatures for Eu1−xLaxB6 (x=0.1 and 0.2), while a sudden drop of ρ(T) was observed at TN for Eu1−xLaxB6 (x=0.3), which is likely due to a loss of magnetic scattering. Here, we discuss the role of unstable magnetization on the anomalous transport properties in the intermediate doped region of Eu1−xLaxB6 (x=0.1, and 0.2).