摘要:

Quasiperiodic (Fibonacci) Ta/Al multilayer films with Ta(110) and Al(111) textures were fabricated by magnetron sputtering. The structure of the multilayers was characterized in detail by x‐ray diffraction. The diffraction peaks at low and high angles can be indexed by the projection method from the high‐dimension periodic structure. The experimental results were in good agreement with the numerical calculation using the model for the compositionally modulated multilayers. The diffraction spectrum of the quasiperiodic Ta/Al multilayers is totally different from that of periodic structure, and the possible application of Fibonacci films as optical elements in a soft x‐ray region is discussed.

ISSN:0003-6951    

DOI:10.1063/1.105937

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

A type IIa natural diamond was irradiated with 300 kV electrons at 16 and 87 K. Transmission electron microscopy and electron energy‐loss spectroscopy were employed to investigate the phase stability of diamond under electron irradiation. At both temperatures, the diamond structure was found to be stable, and the formation of defect clusters was observed. The present results in comparison to previous work on ion implantation indicate that displacement cascade damage is a prerequisite for irradiation‐induced phase transformation from diamond to amorphous carbon or graphite. The temperature dependence of the cluster size suggests that interstitials are thermally mobile above 50 K.

ISSN:0003-6951    

DOI:10.1063/1.105938

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

A new method for obtaining thin silicon film on glass substrates (SOG) has been introduced. This technique uses solid phase epitaxy (SPE) and laser crystallization to fabricate an orientation‐controlled SOG structure. Heat treatment of amorphous SOG substrate in contact with mesa striped (100)‐oriented Si seed crystal was performed at 543 °C for 16 h to form the SPE layer. The most important feature of the present external seeding technique is the separation of the seed from the substrate after SPE. Successful demonstration of seeded laser crystallization shows the usefulness of the external seed SPE.

ISSN:0003-6951    

DOI:10.1063/1.105939

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The sticking probability and molecular size of the growth species were determined as a function of deposition temperature ranging from 700 to 950 °C, in the AlN films prepared from AlCl3and NH3. A novel method was developed, that includes the measurement of the film thickness profile on micron‐sized trenches and the molecular diffusivity of the growth species. The molecular size was about 1 nm at 700–850 °C and decreased gradually with increasing temperature. The sticking probability increased from 0.02 to 0.5 in the temperature range 700–950 °C and, surprisingly, obeyed the Arrhenius law in spite of this large probability of sticking. The activation energy amounted to 136 kJ/mol.

ISSN:0003-6951    

DOI:10.1063/1.106406

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

A 50 °C shift in Curie temperature has been observed forc‐axis oriented PbTiO3thin films using x‐ray diffraction. An analysis of the electrostrictive strain based on the Devonshire thermodynamic formalism showed that the shift in the Curie point for these films can be plausibly explained by an effective two‐dimensional compressive stress of ≊400 MPa. The single‐domain, single‐crystal dielectric susceptibility (&eegr;33) and piezoelectric coefficient (d33) were calculated and found to be relatively unaffected, at room temperature, by a compressive stress of this magnitude.

ISSN:0003-6951    

DOI:10.1063/1.105940

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The thermoelastic transformation of the CuZnAl shape memory alloy has been studiedinsituand in real time by the synchrotron white beam x‐ray topography technique. The evolution of the first martensite lath has been followed during the temperature cycling and its interaction with the crystal structure has been shown.  

ISSN:0003-6951    

DOI:10.1063/1.105941

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Polycrystalline diamond films were deposited on (100) oriented silicon substrates using a microwave plasma disk reactor. Circular delaminations between the diamond thin film and the silicon substrate were produced by Vickers microindentation. While an overall relationship between mean delamination diameter and film thickness was not observed, an unexpectedly strong correlation was observed between delamination diameter and the square root of the coating grain size. A disadvantage of the Vickers microindentation technique is the damage sustained by the Vickers indenter tip after repeated loadings.

ISSN:0003-6951    

DOI:10.1063/1.105942

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Hard diamond‐like carbon films were deposited on Si(100) substrates using a CH4plasma created through electron cyclotron resonance (ECR) heating. The ECR plasma was excited by a Lisitano coil. These films could be deposited with a negative dc bias (−200 V) or a rf‐induced negative self‐bias (−100 V) on the substrates. The deposition rate of the film was about 2.3 A˚/s. The deposited films were characterized by Raman spectroscopy and near‐edge x‐ray absorption fine structure analysis.

ISSN:0003-6951    

DOI:10.1063/1.105943

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We report observations of two distinct types of phase‐separated microstructures in co‐deposited Al‐Ge films. In the initial stages of growth, lateral phase separation is observed, with a temperature dependence consistent with surface diffusion. As the film grows thicker, the Ge‐rich phase becomes increasingly buried, and a transverse phase‐separated microstructure results, consisting of an Al‐rich layer covering a Ge‐rich layer. This observation is explained in terms of the competition between surface and interfacial free energies. We discuss the kinetic aspects of the phase separation process, and the resulting behavior in the thick‐film limit.

ISSN:0003-6951    

DOI:10.1063/1.105944

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Mass spectrometry was applied to study the thermal decomposition of triethylgallium (TEG) on a GaAs (111)B surface. Gallium‐containing species desorbed or reflected from three kinds of differently reconstructed surfaces were measured at 420 °C. The signal intensities of the Ga containing species changed largely with the surface reconstruction in the following order: 2×2 As stabilized ≳&sqrt;19 ×&sqrt;19 Ga stabilized ≳1×1 Ga saturated. This result indicates that larger As coverage suppresses the thermal decomposition of TEG on a GaAs (111)B surface.

ISSN:0003-6951    

DOI:10.1063/1.105945

出版商:AIP    

年代:1991

数据来源: AIP