摘要:

We have observed a large peak in microwave losses, as a function of temperature, in a superconducting Y1Ba2Cu3O7bicrystal containing a large‐area, low‐angle grain boundary. The maximum observed loss was approximately twice the normal state loss. We attribute the peak to enhanced losses occurring within the grain boundary due to the concentration of microwave field lines in the boundary as they are expelled from the superconducting regions. At high microwave powers, bistability in the absorption was observed, resulting in hysteretic absorption curves as a function of bothTand magnetic fieldH.

ISSN:0003-6951    

DOI:10.1063/1.104127

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

In order to investigate the growth mechanism of diamond thin films, theinsituoptical emission spectra of direct current (dc) arc discharge plasma, including the spatial distributions and different CH4/H2ratios, have been measured during the growth processes of diamond thin films prepared by the dc arc discharge plasma chemical vapor deposition method. The results show that there are a great number of atomic hydrogens in the arc discharge plasma. This is the key factor for the growth of diamond films with a high rate and high quality. In addition, the effects of the CH4/H2ratio on the quality of diamond films are discussed in detail in this letter.

ISSN:0003-6951    

DOI:10.1063/1.103368

出版商:AIP    

年代:1990

数据来源: AIP