ABSTRACT
Optical spectroscopy was used to study the electrodynamics and hidden transport properties of a BaFe1.91Ni0.09As2thin superconducting (SC) film. We analyzed the normal state data using a Drude-Lorentz model with two Drude components: one narrow (D1) and another broad one (D2). In the SC state, two gaps with2Δ0(2)/kBTc=1.9-2.0 and2Δ0(1)/kBTc=4.0-4.3 are formed from the narrow component D1while the broad component D2remains ungapped. The calculated total DC resistivity of the film and the low-temperature scattering rate for the narrow Drude component show a hidden Fermi-liquid behavior. The change of total electron-boson coupling (λtot) and representative energy (Ω0) in the normal state with respect to the SC state is typical of other iron-based materials as well as high-temperature superconducting (HTSC) cuprates.
ABSTRACT
Accurate low temperature charge transport measurements in combination with high-precision x-ray diffraction experiments have allowed detection of the symmetry lowering in the single domain Tm0.19Yb0.81B12 crystals that belong to the family of dodecaborides with metal-insulator transition. Based on the fine structure analysis we discover the formation of dynamic charge stripes within the semiconducting matrix of Tm0.19Yb0.81B12. The charge dynamics in these conducting nano-size channels is characterized by broad-band optical spectroscopy that allowed estimating the frequency (~2.4 × 1011 Hz) of quantum motion of the charge carriers. It is suggested that cooperative Jahn-Teller effect in the boron sublattice is a cause of the large-amplitude rattling modes of the Tm and Yb ions responsible for the 'modulation' of the conduction band along one of the [Formula: see text] directions through the variation of 5d-2p hybridization of electron states.
ABSTRACT
The setting up of a vitreoretinal surgery department "Eye Diabetes" and the introduction of the basic rates of medical officers into the structure of an anesthesiological department have increased the flow of patients referred for surgical treatment at the expense of patients with diabetes mellitus (DM). The charges for purchase of diagnostic equipment and medicines, those for additional rates of medical officers are compensated for by the increased activity. The active treatment-and-prevention tactics allows detection of DM, preoperative correction without hospitalization to a speciailized hospital, by reducing the time of preoperative preparation. By taking into account the experience in working with patients with DM and their great need for eye surgical aid, the authors consider it necessary to develop an endocrinological service in future and to set up new medical surgical centers of this specialty.
