We present a combination of elastic neutron scattering measurements in zero and 14.5 T and magnetization measurements in zero and 14 T on underdoped superconducting Ba1−xKxFe2As2 (x = 0.17), and the same measurements in zero field on a nonsuperconducting crystal with x = 0.09. The data suggest that the underdoped materials may not be electronic phase separated but rather have slightly inhomogeneous potassium doping. The temperature dependence of

The low temperature transport properties of Ce75-xAl25+x (x=0, 10, and 15 at. %) metallic glasses were investigated. Magnetic field and composition tuned magnetoresistances changing from negative to positive values were observed at low temperature. It was suggested that these peculiar phenomena were caused by the tunable competition between the Kondo effect and the Ruderman-Kittel-Kasuya-Yoshida interaction in Ce-Al metallic glass with the variation

We characterize the field-induced magnetic phases of SrCu2(BO3)2, a frustrated spin-1/2 Heisenberg antiferromagnet in the two-dimensional Shastry–Sutherland lattice, using specific heat in magnetic fields up to 33 T. We find that the spin gap persists above the expected critical field Hc=Delta/(g*mu_B) of 21 T despite the appearance of magnetic moment in the ground state. At the magnetization plateau at 1/8 of the saturation, the triplets that

High-resolution spin- and angle-resolved photoemission spectroscopy (spin-ARPES) was performed on the three-dimensional topological insulator Bi2Se3 using a recently developed high-efficiency spectrometer. The topological surface state’s helical spin structure is observed, in agreement with theoretical prediction. Spin textures of both chiralities, at energies above and below the Dirac point, are observed, and the spin structure is found to persist

The magnetic susceptibility of Ce1-xLaxOs4Sb12, with x~0.2, exhibits a pronounced maximum at Tm=80 K. This Tm coincides roughly with the temperature below which a small gap, believed to be a hybridization gap, is observed in spectroscopic measurements in undoped CeOs4Sb12. However, a similar anomaly, at a lower temperature of 50 K, is observed in LaOs4Sb12. Furthermore, there is a monotonic variation of Tm with x, for x > 0.2, suggesting the same

We present here high-resolution magnetization measurements on high-quality BaFe2(1−x)Co2xAs2, 0

Heat-capacity measurements on exceptionally high-quality samples of Ba1−xKxFe2As2 give the values of a number of parameters relevant to the electronic structure, the structural/magnetic transition in the undoped parent compound, and the superconducting transition in the near optimally doped, x = 0.41 sample. In BaFe2As2 the changes in the lattice and magnetic structure appear as a single, sharp first-order transition at 140 K; the Sommerfeld coefficient

Soft X-ray absorption and emission spectroscopy was used to determine the electronic density of states of oxygen vacated PrFeAsO. The measured oxygen and iron spectra are in good agreement with mean field theory and local density approximations. Iron-arsenic hybridized spectral features reveal that Fe-As bonding is involved in the process of electron addition near the Fermi-level. X-ray emission and absorption spectra shows an increase in the Fe

Heat capacity, x-ray diffraction, and resistivity measurements on a high-quality BaFe2As2 sample show an evolution of the magnetostructural transition with successive annealing periods. After a 30-day anneal the resistivity in the (ab) plane decreases by more than an order of magnitude, to 12 mu Ohm cm, with a residual resistance ratio ~36; the heat capacity anomaly at the transition sharpens, to an overall width of less than K, and shifts from 135.4

We present systematic studies of magnetic and transport properties of Zn1-xMnxGeAs2 semimagnetic semiconductor with the chemical composition varying between 0.053