摘要:

The microstructure of a silicon nitride/aluminium interface has been identified by analytical transmission electron microscopy. HIPed silicon nitride without any additive was bonded by pure aluminium at 800°C for 15 min. A thin (∼ 5000 Å) reaction layer was recognized at the interface. It consisted of two regions. One an amorphous layer facing the aluminium; it contained aluminium, silicon and oxygen. The other was on the silicon nitride side and consisted of fine particles which were less than 100 Å in diameter. These particles were considered to have β'-sialon type structure.

ISSN:0950-0839    

DOI:10.1080/09500838708228738

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

We propose a novel and rapid method of measuring the total area of a rough surface using a scanning electron microscope. We show, under certain circumstances, that this area is almost exactly proportional to the secondary electron yield from the surface. The relationship of this measurement to fractal characterization is discussed.

ISSN:0950-0839    

DOI:10.1080/09500838708228739

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Two unexpected features have been revealed by transmission electron microscopy investigations of deformed silicon bicrystals:(a)slip ofa/2 ⟨110⟩ dislocations on {001} planes and(b)non-dissociation of Lomer–Cottrell dislocations formed by intersecting slip dislocations.

ISSN:0950-0839    

DOI:10.1080/09500838708228740

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A porous copper residue has been produced by the selective dissolution of aluminium from CuAl2into aqueous alkali solution at 1°C and 93°C. The residue was examined by replica and thin-foil microscopy and found to consist of cylindrical single-crystal copper rods or fibres of very uniform diameter. The fibres were curved but aligned with their average direction approximately parallel to the direction of the de-alloying reaction. The fibres produced by leaching at 93°C were spaced at approximately 110nm intervals, whereas those produced at 1°C were spaced at about 40 nm. All observations are shown to be in accord with a cellular phase transformation model for the de-alloying reaction.

ISSN:0950-0839    

DOI:10.1080/09500838708228741

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The power of parallel recording is demonstrated by the quality of the data obtained when applied to the study of the difference in fine structure for crystalline Al6Mn and quasicrystalline i-AlMn.

ISSN:0950-0839    

DOI:10.1080/09500838708228742

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

We present calculated electron state densities for A1T (T is a transition metal) compounds and icosahedral Al86T14alloys which suggest that the relative stability of different short-range atomic arrangements varies inversely with the electron state density at the Fermi level. Using this argument, we show that the absence ofstable highly coordinated configurations is a necessary, but not sufficient, condition for the existence of icosahedral Al86T14alloys.

ISSN:0950-0839    

DOI:10.1080/09500838708228743

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

It has recently been proposed that the electron microscopic mobility in hydrogenated amorphous silicon is of the order of 100cm2V−1s−1, and that the observed lower mobility values result from scattering by potential fluctuations arising from defect centres which have a negative effective correlation energy. We show that such potential fluctuations cannot lower the mobility to its observed value of 10cm2V−1s−1. Moreover, we find that the experimental evidence used to support the claim of a higher mobility can be adequately explained by the lower of the accepted values.

ISSN:0950-0839    

DOI:10.1080/09500838708228744

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The energy level spectrum of gap states in P-doped a-Si: H has been determined using photo-isothermal capacitance transient spectroscopy (ICTS) with sub-bandgap excitation. Photocapadtance transients were observed in the range from the bandgap energy down to 0·5 eV. It has been deduced that two gap-state features exist in the mobility gap; one is 0·5−0·6 eV below the mobility edge (Ec) of the conduction band, and the other 1·0−1·2 eV belowEc. These results are consistent with our previously reported results on ICTS as well as with defect PL, which were explainedin terms of ‘isolated’ and ‘charge-coupled’ doubly occupied dangling bonds (D−,*D−).

ISSN:0950-0839    

DOI:10.1080/09500838708228745

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In Si and Ge, the optical dispersion parameters (single-oscillator energyEo, dispersion energyEdand bond energy gapEgdeveloped by Wemple and DiDomenico, and Phillips) have been analysed in the temperature range 100-300 K using data obtained by Icenogleet al. EoandEgexhibit a very small temperature dependence in both materials. The thermal coefficients of the dispersion energy, dEd/dT, have opposite signs (Si, –41·9 × 10−4eVK−1; Ge, +37·7 × 10−4eVK−1).

ISSN:0950-0839    

DOI:10.1080/09500838708228746

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The infrared absorption spectra for a sample of Hg1−xCdxTe withx= 0·19 reported previously have been recalculated including both the absorption due to individual carrier transition and that due to collective excitation of carriers (plasmons), taking into account the dispersion of refractive index and the non-parabolicity of the energy band in the absence of Landau damping. The agreement between theory and experiment is good and suggests that free-carrier absorption due to collective excitation can play a noticeable role in the frequency range from ωpup to 2ωpand above. The value of the concentration of ionized impurities thus obtained is believed to be more accurate than that obtained previously.

ISSN:0950-0839    

DOI:10.1080/09500838708228747

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor