12008-05-8Relevant articles and documents
NMR studies of EuB6 at low temperatures
Ambrosini,Gavilano,Vonlanthen,Ott,Young,Fisk
, p. 3361 - 3369 (1999)
We report results of 153Eu and 11B nuclear magnetic resonance (NMR) measurements on EuB6 at temperatures between 0.1 and 150 K and in external magnetic fields between H=0 and 7 T. The evolution of the 153Eu NMR spectra at low temperatures and low fields provides evidence for an unexpected and complex electronic ground state of EuB6, involving the coexistence of two magnetically very similar phases. The temperature and magnetic-field dependences of the 11B spin-lattice relaxation rate T1-1(T,H) are very well accounted for by magnon-driven relaxation. A spin-wave theoretical interpretation of the 153Eu-NMR spectra and the 11B T1-1 measurements indicate that a gap of the order of 1 K exists in the magnon excitation spectrum. 1999 The American Physical Society.
The peculiarities of the structure formation in directionally crystallized eutectics EuB6-MeB2
Paderno,Paderno,Shitsevalova,Filippov
, p. 367 - 371 (2001)
The possibility of producing fiber-strengthened eutectic composites in situ in the quasibinary EuB6-MeB2 (Me-Zr, Hf, Sc) alloys is shown. By directional crystallization of the eutectic composition perfect real structures on the base
Densification, characterization and oxidation studies of novel TiB2+EuB6compounds
Murthy, T.S.R.Ch.,Sonber,Vishwanadh,Nagaraj,Sairam,Bedse,Chakravartty
, p. 85 - 95 (2016)
TiB2+EuB6ceramic samples with different EuB6contents were fabricated using hot -pressing technique. The introduction of EuB6promoted the sinterability, fracture toughness and oxidation resistance of TiB2. 98.7% TD achieved by adding 2.5% EuB6to TiB2by hot pressing at a relatively low temperature of 1750?°C, 35?MPa, 1h. Formation of complete solid solution of TiB2+EuB6observed for all the samples by XRD, EDS and EBSD. Hardness of all samples is measured in the range of 24–27?GPa ～50% higher fracture toughness value of 5.2?MPa?m1/2was obtained in the 2.5% EuB6contained sample compared to monolithic TiB2. Enhancement of oxidation resistance of TiB2was observed by EuB6addition due to the formation of EuBO3and Eu2O3. Oxidized cross section of TiB2+EuB6sample was measured as 340?μm, which is ～35% less than that of monolithic TiB2(520?μm), after oxidation at 1400?°C for 8h.
Electrical transport properties and small polarons in Eu1-xCaxB6
Rhyee, Jong-Soo,Cho, B. K.,Ri, H.-C.
, p. 1 - 8 (2008/10/08)
Temperature- and field-dependent resistivity ρ(T,H) and Hall effect measurements have been carried out for the Eu1-xCaxB6 (x=0.2, 0.4, 0.6, and 0.9) compounds. The replacement of Eu with Ca invoked drastic changes in the ρ(T) although Ca and Eu are isoelectronic. While Eu0.8Ca0.2B6 showed a phase transition similar to that of pure EuB6, the ρ(T) of Eu1-xCaxB6 with x = 0.4 and 0.6 showed a rapid increase at low temperatures (T ≤ 10 K). The upturn of the ρ(T) was suppressed as the magnetic field increased, resulting in negative magnetoresistance (MR). For Eu0.1Ca0.9B6, the MR changed from positive at 10 K ≤ T ≤ 50 K to negative at T~2 K. It was found that the observed exotic ρ(T) is due to the change of the effective carrier density neff and Hall mobility μH determined from the Hall measurements. Analysis of the Hall mobility based on a small polaronic model showed that the carrier transport is dominated by hopping between the polaron sites in a nonadiabatic regime with four-site hopping for the Eu-rich side and three-site hopping for the Eu-poor side of the compounds. This polaronic scenario of the transport is consistent with the observed ρ(T,H), MR(T), neff(T,H), and μH(T) variation.
