摘要:

The mosaic structure of single domain YBa2Cu3O6+x/Y2BaCuO5(123/211) directionally solidified composites is investigated by x‐ray diffraction and transmission electron microscopy. This mosaic structure results from a polygonization process before the oxygenation step. A topological model is given based on the observed distribution of preferred subgrain boundary planes. This polygonization, characteristic of melt textured 123, is proposed to be an intrinsic critical current density limitation for these materials. ©1996 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.362476

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The effective magnetic anisotropy (Keff) of nanocrystalline Fe89Zr7B4soft magnetic alloys with different bcc Fe grain sizes (D) has been investigated by using the law of approach to saturation. The effective magnetic anisotropy of the alloys is found to be considerably depressed. The values ofKefffor the alloys (from 879 to 1038 J/m3) are very close to those of the nanocrystalline Fe73.5Cu1Nb3Si13.5B9soft magnetic alloys, suggesting that the relatively lower permeability of the alloys is independent of the factor ofKeff. With an increase of grain size,Keffis slightly increased. However, the grain size dependence ofKeffis obviously deviated from theKeff∝D6law, which might be mainly attributed to the residual amorphous phase in the alloys. ©1996 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.362471

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A Raman study of InSb etched by reactive ion beam etching using a CH4/H2/N2plasma generated by electron cyclotron resonance is presented. The evolution of the LO, 2LO phonon and phonon–plasmon coupled modes has been studied using resonant Raman spectra in different configurations. Results indicate an increase of the carrier density by a factor of about 60 and a decrease of the built‐in potential due to the plasma process. The combination of both evolutions results in a prevalence of the electric field induced scattering upon the defect induced scattering mechanism. ©1996 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.362472

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Fluorinated and hydrogenated amorphous silicon‐carbon alloys (a‐SiC:H,F) are produced by glow discharge decomposition of SiF4‐CH4‐H2mixture. Small amount of CH4in SiF4‐H2mixture are enough to produce silicon carbon alloys having optical gap ranging between 1.8 and 2.6 eV. Materials, having 1.95 eV band gap and exhibiting optoelectronic properties typical of state of arta‐SiC:H, are deposited under plasma modulation conditions. ©1996 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.362473

出版商:AIP    

年代:1996

数据来源: AIP