The Wiedemann-Franz law in a normal metal-superconductor junction

In this paper the influence of superconducting correlations on the thermal and charge conductances in a normal metal-superconductor （NS） junction in the clean limit is studied theoretically. First we solve the quasiclassical Eilenberger equations, and using the obtained density of states we can acquire the thermal and electrical conductances for the NS junction. Then we compare the conductance in a normal region of an NS junction with that in a single layer of normal metal （N）. Moreover, we study the Wiedemann-Franz （WF） law for these two cases （iN and NS）. From our calculations we conclude that the behaviour of the NS junction does not conform to the WF law for all temperatures. The effect of the thickness of normal metal on the thermal conductivity is also theoretically investigated in the paper.

DETERMINATION OF DEGREE OF CHARGE TRANSFER IN CONDUCTING LANGMUIR-BLODGETT FILM OF BEDT-TTF-TCNQ

A mixed Langmuir-Blodgett film was built up by mixture 1:1 of bis (ethyldithio)tetrathiafulvalene-tetracyanoquinodimethane/stearie acid(BEDT-TTF- TCNQ/SA).A degree of charge transfer(CT)in complex of BEDT-TTF with TCNQ was estimated at 0.477～0,486 by Raman frequencies of central Vc=c and Vc-s,The existence of charge transfer in BEDT-TTF-TCNQ has been confirmed by FTIR and XPS spectroscopy.

Study on rare earth electrolyte of SDC

The grain boundaries of polycrystalline oxygen ion conductors presented a blocking effect on the oxygen ionic transport across them. It was found that the apparent specific grain boundary conductivity was 2-3 orders of magnitude lower than the bulk conductivity in the temperature range of 200-500 °C for normal purity Ce0.85Sm0.15O1.925 (SDC) with an average grain size of 320-580 nm. The apparent specific grain boundary conductivity increased with decreasing average grain size. It was found that the space charge potential was nearly independent of grain size, and the reason was analyzed. The increase of the conduction path width was responsible for the increase in the apparent specific grain boundary conductivity.

Current mechanism and band alignment of Al(Pt)/HfGdO/Ge capacitors

HfGdO high-k gate dielectric thin films were deposited on Ge substrates by radio-frequency magnetron sputtering. The current transport properties of Al（Pt）/HfGdO/Ge MOS structures were investigated at room temperature. The results show that the leakage currents are mainly induced by Frenkel-Poole emissions at a low electric field. At a high electric field, Fowler Nordheim tunneling dominates the current. The energy barriers were obtained by analyzing the Fowler Nordheim tunneling characteristics, which are 1.62 eV and 2.77 eV for Al/HfGdO and Pt/HfGdO, respectively. The energy band alignments for metal/HfGdO/Ge capacitors are summarized together with the results of current-voltage and the x-ray photoelectron spectroscopy.