摘要:

Nanorod/superconductor composites were formed by depositingTl2Ba2Ca2Cu3Oz(Tl-2223) thick films on high density MgO nanorod arrays that were grown on MgO single crystal substrates. Electron microscopy studies show that this approach creates a high density of columnar defects normal to theCuO2planes within crystal grains of the composites. The nanorod/superconductor composites exhibited enhanced critical current densities and an upward shift in the irreversibility line compared with reference samples. These results demonstrate that a nanorod-composite approach represents an effective strategy for introducing correlated defects into high-Tcsuperconductors, and thus may be useful for applications. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119119

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

High frequency magnetic properties of a new, soft magnetic Fe–Cr–Ta–N alloy film have been investigated. Thin films with a composition of Fe-4.6&percent; Cr-0.2&percent; Ta-7.4&percent; N (in atomic &percent;) were prepared by reactive sputtering in a nitrogen-containing atmosphere. The films, most likely nanocrystalline, exhibit excellent soft magnetic properties in the as-deposited condition without any post heat treatment, e.g.,Hcas low as 1.2 Oe (95.3 A/m) and4&pgr;Ms∼20kG. The easy-axisM–Hloop is square. The hard-axis loop is linear and closed, with the anisotropy fieldHa=20–100Oe (1.59–7.95 kA/m). By virtue of their high4&pgr;Msand relatively highHa,these soft magnetic films exhibit high permeability and low loss in the GHz frequency range with the undesirable ferromagnetic resonance interference suppressed to beyond 2 GHz. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119120

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We have studied the magnetization reversal and magnetoresistance behavior in lithographically defined structures based on a 400 ÅNi80Fe20film. The structures consist of square arrays of holes with sizedin the range from 0.5 to 15 &mgr;m fabricated using electron beam lithography and an optimized pattern transfer process. For the field applied along the intrinsic easy axis, a marked increase in the coercive field is observed as the hole size is decreased. This has been attributed to the pinning of the domain walls in the vicinity of the holes. However, for the field applied along the intrinsic hard axis direction, there is a marked increase in the remanence as the hole size is reduced due to the competition between the intrinsic uniaxial anisotropy field and the shape induced magnetic anisotropy field. Unusual magnetoresistance effects are observed as a function of orientation of applied field in submicron structures. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119121

出版商:AIP    

年代:1997

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.119122

出版商:AIP    

年代:1997

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.119123

出版商:AIP    

年代:1997

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.119270

出版商:AIP    

年代:1997

数据来源: AIP