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This paper describes the synthesis of copper/copper oxide nanoparticles via a solution plasma, in which the effect of the electrolyte and electrolysis time on the morphology of the products was mainly examined. In the experiments, a copper wire as a cathode was immersed in an electrolysis solution of a K 2 CO 3 with the concentration from 0.001 to 0.50 M or a citrate buffer (pH ¼ 4.8), and was melted by the local-concentration of current. The results demonstrated that by using the K 2 CO 3 solution, we obtained CuO nanoflowers with many sharp nanorods, the size of which decreased with decreasing the concentration of the solution. Spherical particles of copper with/ without pores formed when the citrate buffer was used. The pores in the copper nanoparticles appeared when the applied voltage changed from 105 V to 130 V, due to the dissolution of Cu 2 O.

The Aharonov-Bohm (AB) effect has been accepted and has promoted interdisciplinary scientific activities in modern physics. To observe the AB effect in condensed matter physics, the whole system needs to maintain phase coherence, in a tiny ring of the diameter 1 µm and at low temperatures below 1 K. We report that AB oscillations have been measured at high temperature 79 K by use of charge-density wave (CDW) loops in TaS 3 ring crystals. CDW condensate maintained macroscopic quantum coherence, which extended over the ring circumference 85 µm. The periodicity of the oscillations is h/2e in accuracy within a 10 % range. The observation of the CDW AB effect implies Frohlich superconductivity in terms of macroscopic coherence and will provide a novel quantum interference device running at room temperature.

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We report a synchrotron X-ray study of charge density waves (CDWs) in an o-TaS 3 crystal. We found that two independent CDWs coexist in the temperature range of 130-50 K. These waves are incommensurate and commensurate CDWs with longitudinal wave vectors q c ¼ 0:252c à and 0:250c à , respectively. The temperature and electric current dependences of the intensity of the two CDW satellites were measured. We found that the commensurate CDW was converted to the incommensurate CDW at 80 K by inducing current flow. Our observation was interpreted in terms of the dynamics of topological defects. We determined the edge dislocation configuration from the electric current dependence of the intensity of the two CDWs. The result implies for the first time that discommensurations are induced in the commensurate CDW by applying an electric field.