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The various phases in Sm 1-xEu xB 6 are investigated based on magnetic susceptibility, resistivity, and Hall effect measurements. The end compounds are a Kondo insulator (SmB 6) and a polaronic ferromagnet (EuB 6). For x≈ 0.2, the ground state undergoes a transition from a Kondo insulator to an antiferromagnetic (AF) insulator phase. Further doping induces a transition to an AF metal at x≈ 0.4. The spin gap is reduced rapidly with the Eu substitution, while there is a charge gap up to x≈ 0.4. The Hall effect indicates a dramatic decrease in the carrier density at low temperatures (T) for the Kondo insulator regime, whereas, the carrier density is almost independent of T in the AF metallic phase. © 2012 American Physical Society.

We investigate the effect of disorder on the superconducting mechanism of MgB2 thin films using low-energy ion irradiation. The c -axis lattice constant and T c of MgB2 thin films change systematically as the magnitude of disorder, which corresponds to the value of average displacements per atom (dpa avg), increases. Here, dpa avg is controlled by the amount of irradiated ions. The dpa avg dependence of the electronâ€"phonon coupling constants (λ) is estimated using the McMillan equation. For dpa avg â©˝ 0.049, λ is linearly proportional to dpa avg. On the other hand, for dpa avg > 0.049, the T c of the disordered MgB2 deviates from the linear fitting curve, and insulating behavior is observed in the normal state resistivity. These results indicate that the superconducting mechanism of MgB2 can be changed by the electronic system caused by disorder strength affecting the electronâ€"phonon coupling constant λ. [ABSTRACT FROM AUTHOR]

Abstract: A polyphenylene sulfide (PPS) substrate is coated with Fe2O3 by ion beam mixing, and the properties of the Fe2O3 coating are investigated. The adhesion of the Fe2O3 coating to the polymer substrate is sufficiently strong, and therefore, the coating is not delaminated even at a high frequency of 20,000Hz. The adhesion strength is evaluated by vibrating the polymer substrate at high frequencies. X-ray diffraction experiments reveal that the Fe2O3 coating is amorphous. In addition, a cross-sectional scanning electron microscope image shows that the Fe2O3 coating has a columnar structure. [Copyright &y& Elsevier]

We investigate the effect of disorder on the superconducting mechanism of MgB2 thin films using low-energy ion irradiation. The c -axis lattice constant and T c of MgB2 thin films change systematically as the magnitude of disorder, which corresponds to the value of average displacements per atom (dpa avg), increases. Here, dpa avg is controlled by the amount of irradiated ions. The dpa avg dependence of the electronâ€"phonon coupling constants (λ) is estimated using the McMillan equation. For dpa avg â©˝ 0.049, λ is linearly proportional to dpa avg. On the other hand, for dpa avg > 0.049, the T c of the disordered MgB2 deviates from the linear fitting curve, and insulating behavior is observed in the normal state resistivity. These results indicate that the superconducting mechanism of MgB2 can be changed by the electronic system caused by disorder strength affecting the electronâ€"phonon coupling constant λ. [ABSTRACT FROM AUTHOR]

Abstract: We employ the point-contact Andreev reflection spectroscopy technique in LuNi2B2C single crystals along three different crystallographic orientations as a function of magnetic field and temperature. Our data taken on the [001] and [110] faces show gap values at of , and , respectively, as analyzed by the one-gap Blonder–Tinkham–Klapwijk model. Both the energy gap and the Dynes broadening parameter exhibit similar dependences on magnetic field along the two directions. Data taken as a function of temperature follow the BCS-like temperature dependence yielding and , respectively. The measured gap values in [100] direction vary from 1.6 to 2.5meV at low temperatures and disappear at the same bulk . [Copyright &y& Elsevier]

H + irradiation increases the surface hardness of polycarbonate. Nano indentation measurement shows that the hardness increases up to 3.7 GPa at the dose of 5 × 10 16 # cm -2 and at the irradiation energy of 150 keV. In addition, the hardness increases with the dose and the energy of H + irradiation. In accordance with the nano indentation measurement, the Fourier-transform infrared spectroscopy (FTIR) depends on the dose and energy of H + irradiation. The peak at ∼1500 cm -1 for the aromatic ring and the peak at ∼1770 cm -1 for the C[double bond, length as m-dash]O stretch decrease with increasing dose and energy, while the increase of the dose and energy develops a new C[double bond, length as m-dash]O stretch vibration at ∼1700 cm -1 and forms aromatic hydrocarbons at ∼1600 cm -1 . X-ray diffraction experiments are also consistent with the nano indentation measurement and FTIR spectra. Based on the experiments, we discuss a possible mechanism of the surface hardness enhancements by ion beam irradiation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)