摘要:

Dissipation anisotropy of a highlyc-axis-oriented (Bi,Pb)2Sr2Ca2Cu3Oxsilver-sheathed tape in the vicinity ofTc(T/Tc>0.9)has been investigated by measuring the dependence of the magnetoresistance on the applied field, the temperature and the angle(&thgr;)between the magnetic field direction and the tape surface. The results show that the dissipation anisotropy increases with the increase of the field and the temperature. It is found that the dissipation is only related to the magnetic field component perpendicular to the tape surface(c-axis component), i.e.,R(H,&thgr;)=R(Hsin&thgr;). The experimental results can be accounted for in terms of the easy motion of two-dimensional (2D) pancake vortices along the CuO2planes. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118201

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Metal rings with inner diameters of 1 and 5 &mgr;m, fabricated using electron-beam lithography, were used to calibrate magnetic force microscopy (MFM). A MFM tip’s effective magnetic charge,q, and effective magnetic moment along the tip’s long axis,mz,can be determined from the MFM signal of the ring at a different scan height and a different electric current in the ring. The magnetic moments in the directions transverse to the tip’s long axis were estimated by a straight current wire. It was found that for a Si tip coated with 65 nm cobalt on one side,qis2.8×10−6emu/cm,mzis3.8×10−9emu, andmxandmyare in the order of10−13emu, which are negligible compared withmz.Furthermore, the MFMs sensitivity to the second derivative of the magnetic field was determined from the minimum ring current for a measurable MFM signal to be 0.1Oe/nm2. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118808

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We have succeeded in growing monocrystalline ferrimagneticMn2Sbthin films on (001) GaAs by molecular-beam epitaxy. From the reflection high-energy electron and x-ray diffraction patterns, the orientation ofMn2Sbfilms grown on (001) GaAs substrates was found to be with thecaxis normal to the surface. This direction is also the easy magnetization direction as determined by superconducting quantum interference device measurements at room temperature. Magneto-optical spectra of these films showed a much larger magneto-optical Kerr effect than bulk data from the infrared to the blue wavelength region. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118809

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We have investigated the potential use of AlF3thin films (50 nm thick) as negative inorganic resist layers for focused ion beam nanolithography. We demonstrate that 10 nm-wide lines can be fabricated using a Ga+beam of 30 keV incident energy. The resist sensitivity of 1010Ga+/cm is two orders of magnitude lower than for polymethylmethacrylate organic resist. We emphasize that this low sensitivity associated with the exposure mechanism of the resist minimize the influence of the tails of the current distribution within the ion spot. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118810

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Time-resolved measurements of the passage of holes through thin layers of tris-(8-hydroxyquinolinato) aluminum (Alq) sandwiched between two hole-transporting layers give an effective mobility of order10−6–10−5 cm2/V s,hole range of 10–30 Å, and effective activation energy of 0.12 eV. Phenomenological mobilities, hole ranges, and overall transmission probabilities through the Alq depend strongly on electric field strength and temperature. These hole injection and transport characteristics of Alq affect the behavior of electroluminescent devices based on these materials and, in particular, the location of the recombination zone. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118811

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

ISSN:0003-6951    

DOI:10.1063/1.119080

出版商:AIP    

年代:1997

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.118813

出版商:AIP    

年代:1997

数据来源: AIP