Multiple ferromagnetic structures in an off-center rattling system Eu8Ga16Ge30
نویسندگان
چکیده
منابع مشابه
Off-center phonon scattering sites in Eu8Ga16Ge30 and Sr8Ga16Ge30
We present a detailed extended x-ray absorption fine structure sEXAFSd analysis of the thermoelectric clathrates Eu8Ga16Ge30 and Sr8Ga16Ge30, both of which have an unusually low thermal conductivity attributed to a “rattler” motion of the filler atoms Eu and Sr. The EXAFS results show that the Ga/Ge lattice is quite stiff with a high correlated Debye temperature ,400 K. Eu is on-center in the s...
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We present optical conductivity studies of the type-I clathrate Ba8Ga16Sn30, using a terahertz time-domain spectrometer (0.3-3.0 THz). The lowest-lying spectral peak at 0.72 THz due to the Ba(2) ion's off-center vibration in the oversized cage shows a drastic and anomalous temperature dependence. Below about 100 K, the single broad peak splits into two subpeaks, and with further lowering of the...
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Dynamical motions of the guest ions in type-I clathrates Sr8Ga16Si(30-x)Gex and Ba8Ga16Si(30-x)Gex have been studied by Raman scattering spectroscopy, to clarify the role of guest vibration modes in these systems with unusual thermal transport behaviors. An anomalous decrease of the guest energies with decreasing temperature is observed for both systems. The Ge-doping expands the cage surroundi...
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The Hall resistivity xy , resistivity xx , and magnetization of three metallic ferromagnets are investigated as a function of magnetic field and temperature. The three ferromagnets, EuFe4Sb12 Tc 84 K , Yb14MnSb11 Tc 53 K , and Eu8Ga16Ge30 Tc 36 K are Zintl compounds with carrier concentrations between 1 1021 and 3.5 1021 cm−3. The relative decrease in xx below Tc xx Tc / xx 2 K is 28, 6.5, and ...
متن کاملAn Off-Center “Coaxial” Cable
A “coaxial” transmission line has inner conductor of radius a and outer conductor of radius b, but the axes of these two cylinders are offset by a small distance δ ¿ b. Deduce the capacitance and inductance per unit length, and the impedance Z, accurate to order δ/b. The (relative) dielectric constant and permeability of the medium between the two conductors both unity. The relevant frequencies...
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ژورنال
عنوان ژورنال: Journal of Physics: Conference Series
سال: 2010
ISSN: 1742-6596
DOI: 10.1088/1742-6596/200/2/022044