In February 1999, the second Scanned Probe Microscopy conference (SPM II) of the Australian Scanned Probe Microscope Society was held in Sydney, Australia, in conjunction with the fifth biennial symposium of the Australian Microbeam Analysis Society (AMAS V). This issue of Microscopy and Microanalysis presents selected full-length papers arising from that meeting.

The technique of atomic force microscopy (AFM) soft-imaging is outlined with respect to characterizingthe adsorption of surfactants and polymers at the solid/liquid interface. This method utilizes theelectrostatic and steric repulsion forces between the scanning probe and the sample to allow sensitive placementof the imaging probe near to the delicate surface layer. Specifically, the mixed adsorption of sodium dodecylsulfate(SDS) and poly(vinyl pyrrolidone) (PVP) on graphite is examined. Unlike the adsorbed layer in asolution of either component, the adsorbed layer in the mixture does not cover the substrate uniformly untilequilibrium is reached (often hours later). The interesting kinetic and coverage effects observed are significantto the many applications reliant on adsorption from polymer-surfactant mixtures, especially to the flocculationof dispersions.

The preparation of ultra flat gold surfaces for use in chemical force microscopy (CFM) has beenstudied. The surfaces were studied in terms of substrate effects by comparing mica, Si (110) wafer and glassslides. The effect of different annealing regimes was also investigated. Measurements on these surfaces weremade by both atomic force microscopy (AFM) (in contact and tapping mode) and by scanning tunnelingmicroscopy (STM). The films contain different morphologies with respect to grain size and topography.Calculations of surface roughness present values less than 2.5 nm for all surfaces studied, making the choice ofthe flattest surface difficult if based on criteria of surface roughness alone. Additionally, it is shown thatdifferent acquisition parameters can produce dissimilar images that have stability and reproducibility.

The atomic force microscope (AFM) has previously been applied to the measurement of surfaceforces (including adhesion and friction) and to the investigation of material properties, such as hardness. Herewe describe the modification of a commercial AFM that enables the stiffness of interaction between surfacesto be measured concurrently with the surface forces. The stiffness is described by the rheological phasedifference between the response of the AFM tip to a driving oscillation of the substrate. We present theinteraction between silica surfaces bearing adsorbed polymer, however, the principles could be applied to a widevariety of materials including biological samples.

Technologies such as compact disc (CD) manufacturing, hologram embossing, and security printingrely on the reproduction of micro-patterns generated on surfaces by optical or electron-beam lithographicwriting onto electron-beam or photoresists. The periodicity of such patterns varies from sub-micron to severalmicrons, with depths up to 0.5 μm. The scanning probe microscope (SPM) is becoming a routine tool foranalysis of these micro-patterns, to check on depths and lateral dimensions of features. Direct scanning ofresist-covered plates is now possible, without damage, using resonant low-contact force SPM with etched siliconcantilevers. Metal shims produced from the master resist plates can also be scanned and checked for defectsprior to production of embossed foils. The present article discusses examples of the use of a Digital Instruments3100 microscope in analysis of production electron-beam lithography plates with a 0.5 μm resist thickness. Wealso examine features of nickel replicas (father and mother shims) produced by electroforming from theoriginal plate. With SPM measurements of the development profile of a particular plate, corrections can bemade to exposures and development times during production to correct errors. An example is given of sucha feedback process.

Atomic force microscope images of aluminium sheet are used to calculate the mean roughness Ra andthe root mean square roughness Rq for different directions ([theta]) across the samples. The angle determined valuesof Ra([theta] and Rq([theta]) are significantly lower in the rolling direction than in any other direction. The resultsprovide a clear demonstration of the vector nature of surface roughness. Local features in an angle determinedRq([theta]) profile are also compared with the positions of peaks and valleys in the matching topographical crosssectionof the surface running at right angles to [theta]. It is further found that the distribution of z heights for animaged sample is usually not Gaussian in shape unless the z heights are measured about mean lines constructedacross the surface parallel with the rolling direction. The results are relevant for controlling lubricationperformance in the aluminium rolling process.

In truly standardless electron microprobe analysis, generated X-ray intensities calculated from firstprinciples are combined with a detector efficiency model. Though already used for energy dispersive (ED)analysis, the application of this concept to wavelength dispersive (WD) analysis is problematic, mainly becausethe reflectivity of spectrometer crystals is not well known. However, the need to carry out standard measurementswith every batch of WD analyses can be avoided by using stored intensity data, and interpolation maybe used when no standard is available. An empirical adjustment factor allowing for changes in spectrometerefficiency with time can be applied as necessitated by the variability of the spectrometer characteristics and theaccuracy required. A similar approach to background corrections, based on measured continuum intensities,can be used. While the convenience of standardless WD analysis is attainable only at the expense of reducedaccuracy, it can have a useful role where high accuracy is not needed or as a preliminary to applying a morerigorous routine using standards.

The effect of multiple scattering in a turbid medium on single-photon and two-photon fluorescencemicroscopy is experimentally investigated for different scattering characteristics including scattering anisotrophyand optical thickness of a turbid medium. It is demonstrated that two-photon excitation can providesignificant improvement in penetration depth through turbid media, due to reduced scattering experienced bythe excitation beam. It is also shown that the limiting factor in obtaining high-quality images under singlephotonexcitation is the fast degradation of image resolution caused by multiple scattering, while for twophotonexcitation it is limited by the degradation of image contrast due to the reduction in fluorescencestrength.

Energy-filtered transmission electron microscopy (EFTEM) can be used to acquire elemental distributionimages at high lateral resolution within short acquisition times. In this article, we present an overviewof typical problems from materials science which can be preferentially solved by means of EFTEM. In the firstexample, we show how secondary phases in a steel specimen can be easily detected by recording jump ratioimages of the matrix element under rocking beam illumination. Secondly, we describe how elemental maps canbe converted into concentration maps. A Ba-Nd-titanate ceramics serves as a typical materials science exampleexhibiting three different compounds with varying composition.