摘要:

In this letter, we present results of experiments in which nuclear magnetic resonance (NMR) signals were detected using an untuned pickup coil coupled to a high temperature superconductor (HTS) based superconducting quantum interference device (SQUID). We were able to operate the HTS SQUID in the presence of static fields of up to 500 Gauss and radio frequency fields of up to 6 Gauss. The ability of a HTS SQUID to detect NMR signals opens up the possibility of using a sensitive detector for practical applications involving NMR that require a broad detection bandwidth. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118436

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We tried to design the magnet exhibiting magnetic pole (N and S) inversion by photostimuli. The magnetization ofFe1.5IICrIII(CN)6⋅7.5H2Owas changed in a photon mode by visible light. A ferro-ferrimagnet(Fe0.40IIMn0.60II)1.5CrIII(CN)6⋅7.5H2Omixed by ferromagnetic (Fe–Cr system showing the change of magnetization by optical stimuli) site and ferrimagnetic (Mn–Cr system showing no optical response) site showed negative magnetization at the temperature lower than compensation temperature(Tcomp=19 K). In this mixed metal cyanide magnet we have succeeded in demonstrating a novel magnetic behavior “photoinduced magnetic pole inversion.” Moreover, the magnetic pole inversion can be induced repeatedly by alternate optical and thermal stimulations. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118475

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Iron nanowire arrays have been grown by shadow deposition on a self-organized grating template produced by annealing the sodium chloride (110) surface. The typical wire size as measured using transmission electron microscopy is 45 nm×13 nm×10 &mgr;m. The typical wire array period is 90 nm. The magnetic properties were dominated by a strong in-plane shape anisotropy. The hysteresis loops examined by magneto-optical Kerr effect measurements indicated coherent switching, even though the individual wires were isolated from one another. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118437

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report the evolution of the magnetoresistance (MR) and magnetization behavior ofNi80Fe20wire arrays as the width (w) is reduced from 200 to 0.3 &mgr;m. At around 1.5 &mgr;m width, the hysteretic behavior seen in continuous films shows the near reversible behavior characteristic of spin rotation processes. At low field(H<Ms),the anisotropic magnetoresistance determines the response and is strikingly size dependent. At high field(H>Ms),the linear MR response to the in-plane perpendicular hard axis field suggests a bulklike transverse MR effect. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118438

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The ion current and sheath impedance were measured at the radio-frequency-powered electrode of an asymmetric, capacitively coupled plasma reactor, for discharges in argon at 1.33–133 Pa. The measurements were used to test the models of the radio frequency sheath derived by Lieberman [IEEE Trans. Plasma Sci.17, 338 (1989)] and Godyak and Sternberg [Phys. Rev. A42, 2299 (1990)], and establish the range of pressure and sheath voltage in which they are valid. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118464

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report on the measurement of methyl radical(CH3)densities in a low-density supersonic arcjet plasma used in the synthesis of diamond films. Single-pass, high-sensitivity ultraviolet (UV) absorption spectroscopy has been employed to study theX(2A2″)→B(2A1′)transition of the methyl radical near 216 nm. The minimum detectableCH3density is found to be∼4×1013 cm−3, which corresponds to a fractional absorption of2×10−3at a gas temperature of 1200 K. The dependence of the measured methyl column density on pressure andCH4/H2flow ratio has been studied. The results are used to revise our previous estimates of the reactive “sticking” coefficient forCH3, and we now find that it is of order10−2under conditions where we have previously documented the growth of high quality diamond films. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118439

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

ISSN:0003-6951    

DOI:10.1063/1.118440

出版商:AIP    

年代:1997

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.118472

出版商:AIP    

年代:1997

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.119268

出版商:AIP    

年代:1997

数据来源: AIP