摘要:

Superconducting YBa2Cu3O7−&dgr;thin films withTc=89.5 K were deposited on MgLaAl11O19(11¯0) substrates by pulsed laser deposition. X‐ray diffraction patterns indicate that the YBa2Cu3O7−&dgr;films were epitaxial films, with thecaxis perpendicular to the substrate surfaces. Microstrip resonators of YBa2Cu3O7−&dgr;thin films deposited on MgLaAl11O19substrates were fabricated. The loaded quality factor of the resonator was 1007 at 77 K and 4.28 GHz. As a new substrate for highTcoxide superconducting films, MgLaAl11O19substrates are especially suitable for superconducting‐microwave applications.

ISSN:0021-8979    

DOI:10.1063/1.354611

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

A model is developed to study the temporal evolution of the sheath during a pulse of high negative voltage applied to a target immersed in a plasma, such as that present in plasma source ion implantation. This model covers the whole range from collision free to collision dominated sheaths. The sheath expansion velocity and the position of the sheath edge as a function of time in planar geometries for various pressures are obtained.

ISSN:0021-8979    

DOI:10.1063/1.354612

出版商:AIP    

年代:1993

数据来源: AIP

摘要:

The retracing behavior of the phase‐matching angle (RBPA) of many nonlinear optical crystals in optical parametric oscillators (OPO) is reported here. The wavelength range of the pump wave and the tuning angle range over which RBPA can occur are obtained. Furthermore, the generality of this novel and interesting phenomenon is successfully explained by theoretical analysis. We point out that RBPA exists generally in both type I and type II OPO’s by using either uniaxial or biaxial crystals.

ISSN:0021-8979    

DOI:10.1063/1.354613

出版商:AIP    

年代:1993

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.354614

出版商:AIP    

年代:1993

数据来源: AIP