We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study on the measurement of composition in organic depth profiling. Layered samples with known binary compositions of Irganox 1010 and either Irganox 1098 or Fmoc-pentafluoro-l-phenylalanine in each layer were manufactured in a single batch and distributed to more than 20 participating laboratories. The samples were analyzed using argon cluster ion sputtering and either X-ray photoelectron spectroscopy (XPS) or time-of-flight secondary ion mass spectrometry (ToF-SIMS) to generate depth profiles. Participants were asked to estimate the volume fractions in two of the layers and were provided with the compositions of all other layers. Participants using XPS provided volume fractions within 0.03 of the nominal values. Participants using ToF-SIMS either made no attempt, or used various methods that gave results ranging in error from 0.02 to over 0.10 in volume fraction, the latter representing a 50% relative error for a nominal volume fraction of 0.2. Error was predominantly caused by inadequacy in the ability to compensate for primary ion intensity variations and the matrix effect in SIMS. Matrix effects in these materials appear to be more pronounced as the number of atoms in both the primary analytical ion and the secondary ion increase. Using the participants' data we show that organic SIMS matrix effects can be measured and are remarkably consistent between instruments. We provide recommendations for identifying and compensating for matrix effects. Finally, we demonstrate, using a simple normalization method, that virtually all ToF-SIMS participants could have obtained estimates of volume fraction that were at least as accurate and consistent as XPS.

Multiferroics are promising for sensor and memory applications, but despite all efforts invested in their research no single-phase material displaying both ferroelectricity and large magnetization at room-temperature has hitherto been reported. This situation has substantially been improved in the novel relaxor ferroelectric single-phase (BiFe 0.9 Co 0.1 O 3 ) 0.4 -(Bi 1/2 K 1/2 TiO 3 ) 0.6 , where polar nanoregions (PNR) transform into static-PNR (SPNR) as evidenced by piezoresponse force microscopy (PFM) and simultaneously enable congruent multiferroic clusters (MFC) to emerge from inherent ferrimagnetic Bi(Fe,Co)O 3 regions as verified by magnetic force microscopy (MFM) and secondary ion mass spectrometry (SIMS).On these MFC, exceptionally large direct and converse magnetoelectric coupling coefficients, α ≈ 1.0 x 10 -5 s/m at room-temperature, were measured by PFM and MFM respectively. We expect the non-ergodic relaxor properties which are governed by the Bi 1/2 K 1/2 TiO 3 component to play a vital role in the strong ME coupling, by providing an electrically and mechanically flexible environment to MFC. This new class of non-ergodic relaxor multiferroics bears great 3 potential for applications. Especially the prospect of a ME nanodot storage device seems appealing.

The kinetic excitation of hot electrons and conduction-band vacancies following the impact of an energetic particle onto a solid surface was studied using metal-insulator-metal tunnel junctions. The top metal layer ͑polycrystalline silver͒ was bombarded by charged and neutral Ar projectiles of kinetic energies between 1 and 15 keV. Hot charge carriers generated within the collision cascade initiated by the projectile impact were detected as a tunneling current across the oxide barrier into the underlying substrate metal electrode. The tunneling yield is shown to depend monotonously on the kinetic impact energy with no notable contribution of potential emission. The dependence, however, is different for singly charged and neutral projectiles. Applying a bias voltage between the two metal electrodes, information about the energy spectrum of the excited carriers is obtained. The experimental data are interpreted in terms of a simple two-temperature tunneling model, yielding a kinetically induced transient electron "temperature" on the order of 10 4 K.

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