Electronic and magnetic structures of EuB6: The effects of pressure and doping

Semimetallic Nature and Magnetic Polarons in EuB6 Studied by Angle-Resolved Photoemission Spectroscopy

“…The separation between two bands is about 0.35 eV, the origin of which should be the exchange interaction between the valence band and the local 4f moments that have an FM order, as observed in the ARPES spectra of Gd metal [34]. Since the B 2p band has an AFM Kondo coupling to the Eu 4f states [5], we can assign the upper/lower band as the majority/minority-spin band denoted by red/blue arrows in the lower panels, and their separation is comparable to theoretical estimations [5,6].…”

“…Figure 3(a) shows the FS map of EuB 6 in the PM phase at T = 40.7 K. As expected, we can observe a weak electron pocket around the X (1) point (Eu 5d signals vanish as approaching the X (1) point as seen in Fig. 2(c)), the volume of which is nearly a half of that by band calculations for an antiferromagnetic (AFM) phase to mimic the PM one [6]. Around the X (2) point, there is a more intense spot in contrast to Fig.…”

“…It has been proposed that the low carrier density is essential to stabilize the FM order in a Kondo lattice system [3]. According to the LDA or LDA+U band calculations [4][5][6], the Eu 5d and the B 2p bands overlap each other and form small electron and hole pockets, respectively, centered at the X point in the Brillouin zone (BZ), to produce low-density carriers. This picture is experimentally supported by Shubnikov-de Haas and de Haas-van Alphen (dHvA) measurements [7,8], optical conductivity [9,10], Andreev reflection spectroscopy [11], and resonant inelastic x-ray scattering [12].…”

Effect of pressure on the electric transport properties of carbon-doped

“…According to theoretical studies [9], both electron doping, as well as pressure enhance the FM interaction between Eu atoms. In agreement with this assump- * E-mail: batkova@saske.sk; Fax: +421 55 633 6292; Telephone: +421 55 792 2239 tion experiments [10,11,8] show that increasing pressure continuously reduces the resistivity of EuB 6 and enhances the temperature of FM ordering.…”

The magnetocaloric, magnetic, optical, and thermoelectric properties of EuB6 compound: DFT and Monte Carlo study

“…The ferromagnetic (FM) semimetallic ground state, with one Eu 5d electron pocket and one B 2p hole pocket for each spin, is obtained theoretically by studying the electrical characteristics of EuB 6 in prior research. [7][8][9] Two FM transitions at T c1 = 15.3 K and T c2 = 12.5 K are seen in all examined characteristics, according to temperature-dependent X-ray diffraction. 6 Further evidence for the FM ordering of EuB 6 with a transition temperature of 13.7 K can be found in Ref.…”