摘要:

Measurement of linear nanometric distances between perfectly smooth plane parallel surfaces by scattering evanescent waves of internally reflected light is shown to be possible if one of the two surfaces is optically disseminative, that is, it either possesses a heterogeneous index of refraction or it is capable of absorbing and re‐emitting radiation. Good agreement was obtained between the nominal 100 nm fly height of a magnetic recording slider and the 92 nm fly height measured by scattered total internal reflection. This method is simpler and more informative than interferometry or methods that employ the internally reflected beam. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116900

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Color‐variable emission has been observed from a multilayer polymer electroluminescent device composed of three polymer layers: perfluoropropylated poly(p‐phenylene) (F‐PPP) sandwiched between two emissive polymers, poly (3‐dodecylthiophene) (PDT) and poly (p‐phenylenevinylene) (PPV). Green and red emissions were observed when a negative bias was applied to the PPV and PDT side electrodes, respectively. F‐PPP was supposed to act as an electron‐blocking layer due to its small electron affinity (2.2 eV) compared with those of PPV (2.7) and PDT (3.5), and to facilitate the confinement of the excitons in the negatively biased polymer layer, where the radiative recombination of the charge carriers takes place. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116901

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We present novel techniques to selectively excite the lowest order symmetric (So) and antisymmetric (Ao) Lamb wave modes in thin solid plates. Hertzian contacts are formed between the plates and the end of specially designed quartz rods which guide extensional waves generated by PZT‐5H transducers bonded at their other end. Mode selectivity is achieved by applying shear and/or longitudinal traction at the edge or the surface of the plates according to the results of a two‐dimensional normal mode theory. In aluminum plates, mode selectivity is measured as a function of frequency for different traction forces. With normal forces,Aomode selectivity of more than 46 dB is obtained forfd<0.4 MHz mm. With antisymmetric shear traction at the edge of the plate, a selectivity exceeding 55 dB is achieved for single modeSooperation. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116902

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The kinetic energy of a neutral stream within Ar electron cyclotron resonance plasma was evaluated by means of time‐of‐flight mass spectroscopy. The median energy in the distribution of the neutral stream ranged between 10 and 20 eV for pressure from 1.4 to 2.9×10−4Torr. This energy is almost equal to that of the ions. The energy of the neutral stream could be controlled by adjusting the gas pressure. A higher pressure broadened the energy distribution of the neutral stream. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116903

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

High quality diamondlikea‐C:H has been deposited, at low ion bombardment energies, from an expanding thermal argon/acetylene plasma at high growth rate. It is observed that quality improvement, in terms of hardness, is equivalent to maximization of the refractive index. The highest refractive indices are obtained when the admixed acetylene flow and the argon ion flux emanating from the plasma source are comparable in magnitude, which suggests critical loading. This also indicates that the acetylene has to be dissociated only once. Combination with the observed quality behavior at higher deposition rates suggests that there is one preferred hydrocarbon radical for deposition, probably C2H. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116904

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Heteroepitaxial growth of Fe on the asymmetrical Cu(311) surface leads to (211)‐oriented strained bcc films with a highly anisotropic morphology. In the initial stage the evolution of pseudomorphic Fe islands is observed: anisotropic lateral stress induces the formation of a regular array of Fe patches with a periodic separation. With proceeding growth, the overlayer transforms to bcc structure by means of dislocations introduced along the direction of dominant stress. The topography of the resulting bcc film corresponds to a regular faceted structure whose periodicity is determined by the arrangement of pseudomorphic islands formed in the initial stage of growth. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116905

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Unhydrogenated amorphous carbon films were deposited by rf magnetron sputtering at room temperature.Insituspectroscopic ellipsometry and real time ellipsometry were used to monitor and characterize the films during deposition as well as to define the region of the preparation conditions where carbon films rich insp3C–C bonds are deposited. Evidence that the amorphous films exhibit the diamond character as well as their metastability were also provided and discussed by Raman spectroscopy and other techniques. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116906

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Epitaxial metallic LaNiO3(LNO) films on SrTiO3(STO) were prepared by metalorganic decomposition. X‐ray &thgr;–2&thgr; scans, x‐ray &fgr; scans, and the Rutherford backscattering channeling technique were used to determine the degree of crystallinity of the films. The trend of resistance as a function of annealing temperature of LNO films on STO and Si substrates indicated that LNO films on STO have lower crystalline temperature and higher transition temperature from conductor to insulator than on Si. (001)‐oriented PbTiO3(PT) films were grown on LNO‐coated STO by the sol‐gel method. Scanning electron microscopy of a cross section of PT/LNO/STO showed sharp boundaries. The ferroelectric capacitor fabricated from these films displayed promisingP‐Ehysteresis characteristics. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117358

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We have determined the orientational distribution function (ODF) of side chains of rubbed polyimide (PI) films and liquid crystal (LC) monolayers on those films (PI & LC) by optical second‐harmonic generation (SHG). To separate the SHG signal of the LC monolayer from that of the (PI & LC) film, the phase difference between the SHG signals from PI and (PI & LC) was measured by an interference method. We found that the ODFs of PI and LC films are quite different. However, serious changes in these ODFs occur at the same rubbing strength, where the pretilt angle also shows a remarkable change. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117359

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Potassium niobate (KNbO3) thin films have been deposited on silicon (Si) and strontium titanate (SrTiO3) substrates by metalorganic chemical vapor deposition. Stoichiometric KNbO3films were obtained by adjusting the partial pressure of precursors. The crystallinity was examined by x‐ray diffraction and reflection high‐energy electron diffraction. Single‐crystal (010) KNbO3films with smooth surface were heteroepitaxially grown on (110)SrTiO3substrate at 850 °C. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117360

出版商:AIP    

年代:1996

数据来源: AIP