11B nuclear quadrupole interaction in metal hexaborides (MB6)
作者:M. Aono、S. Kawai
DOI:10.1016/0022-3697(79)90033-7
日期:1979.1
and trivalent-metal hexaborides (MB 6 ) as well as in mixed-valent SmB 6 has been measured by the nuclear magnetic resonance method. In each group of divalent- and trivalent-metal hexaborides, ¦ eq ¦ decreases remarkably with increasing lattice parameter. At a given lattice parameter, ¦ eq ¦ for the trivalent-metal hexaborides is smaller than that for the divalent-metal hexaborides. The value of ¦ eq
Abstract TiB 2 +EuB 6 ceramic samples with different EuB 6 contents were fabricated using hot -pressing technique. The introduction of EuB 6 promoted the sinterability, fracture toughness and oxidation resistance of TiB 2 . 98.7% TD achieved by adding 2.5% EuB 6 to TiB 2 by hot pressing at a relatively low temperature of 1750 °C, 35 MPa, 1h. Formation of complete solid solution of TiB 2 +EuB 6 observed
Submicron crystalline rare-earth hexaborides (RB6 ; R = Sm, Eu, Gd, and Tb) have been successfully prepared by a facile one-step solid-state reaction of RCl 3 ·6H 2 O, B 2 O 3 , and Mg powder in an autoclave at the relatively low temperature of 500 °C. By controlling the reaction conditions, submicron-sized cubes (RB6 ) and rod- and needlelike SmB6 are obtained. The possible growth mechanism of
Abstract Magnetic structures of pure and carbon-doped europium hexaboride EuB 6−x C x , were determined by neutrondiffraction on powders prepared from 11 B and 153 Eu. EuB 6 is a simple ferromagnet, whereas the x = 0.20 compound has an incommensurate spiral structure with propagation vector τ = (0.28, 0, 0). Data for a magnetically inhomogeneous intermediate composition, x = 0.05, indicate a mixture
摘要 纯的和碳掺杂的六硼化铕 EuB 6-x C x 的磁结构是通过对由 11 B 和 153 Eu 制备的粉末进行中子衍射确定的。EuB 6 是简单的铁磁体,而 x = 0.20 化合物具有不公度的螺旋结构,传播矢量 τ = (0.28, 0, 0)。磁性非均匀中间成分的数据 x = 0.05,表示铁磁域和螺旋磁域的混合,τ = (0, 0, 0.104)。EuB 6-x C x 中的螺旋磁性源于铁磁近邻交换和传导电子引起的反铁磁相互作用之间的竞争。
Electronic transport in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Eu</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn><mml:mi>−</mml:mi><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Ca</mml:mi></mml:mrow><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">B</mml:mi></mml:mrow><mml:mrow><mml:mn>6</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>
作者:S. Paschen、D. Pushin、M. Schlatter、P. Vonlanthen、H. R. Ott、D. P. Young、Z. Fisk
DOI:10.1103/physrevb.61.4174
日期:——
We have measured the electrical resistivity, the magnetoresistance, the Hall effect, and the magnetization in varying temperature ranges between 0.3 and 300 K on single crystals of EuB6, CaB6, and Eu0.8Ca0.2B6. The ferromagnetic phase transition of EuB6, marked by a sharp peak in the temperature dependence of the electrical resistivity p(T) just below 16 K, is shown to be accompanied by a considerable increase of the effective charge carrier concentration n(eff). The overall features of the transport properties of Eu0.8Ca0.2B6 are similar to those of EuB6. A phase transition at 5.3 K has been established. However, the increase of n(eff) across this phase transition by two orders of magnitude is much more pronounced than in pure EuB6.