Fig. 1. Layered LiCoO2 structure. Li Co O from the anode, migrated across the electrolyte, and intercalated again to the empty octahedral site between layers in the cathode (deficit of Li is decreased and cathode transforms to LiCoO2 again), the compensating electrons go to the external electrical circuit. Such a completely reversible lithium intercalation process is the key to the rechargeable Li battery. It is the ordinary process for any non-defective lithium battery.

Atomic force microscopy (AFM) is routinely applied for compositional mapping of heterogeneous polymer materials. Recognition of the individual components in these materials is usually based on their specific morphology and differences of local mechanical and electric properties. Nowadays a deficit of local chemical or spectral information in AFM can be overcome by combining it with confocal Raman scattering microscopy [1, 2]. Such applications to polymer blends are fast developing and can be substantially enhanced with the use of multi frequency AFM techniques, which allow the simultaneous recording of surface morphology, local mechanical, dielectric and chemical (Raman spectra) responses from the same sample area. Initial efforts in this direction are presented in our work, which was focused on studies of films of immiscible blend of polystyrene (PS) and polyvinyl acetate (PVAC). Interplay between Raman Scattering and Atomic Force Microscopy in Characterization of Polymer Blends

We present cantilever-probe based scanning near-field microscopy (SNOM) studies of GaInP microdisks resonators (radii R=2 um and quality factors Q∼1000) with embedded InP quantum dots (QDs) emitting at ∼750 nm. Near-field photoluminescence spectroscopy in collection regime, using side excitation from micro-objective, was used for imaging of whispering-gallery modes (WGMs) with a spatial resolution below the light diffraction limit. Using collection-illumination regime we imaged the position of single InP/GaInP QDs in microdisk.

Proposed a method of measurements for both electrical field enhancement and size of near-field localization area for plasmonic antenna-probe. The method is based on optical modification of photosensitive sample. Shown the results of the proposed method and subdiffraction resolution of test image is demonstrated.

A technique of cantilever based scanning near-field optical microscopy is applied. Using InP/GaInP quantum dots structures, 100nm (lambda/7) spatial resolution of the technique in illumination-collection regime is tested. The possibility to obtain optical data with a subdiffraction resolution is exploited for clarifying the transversal electric field mode configuration of the radiating semiconductor laser.

Scanning near-field optical microscopy was applied to study, with sub-wavelength spatial resolution, the near- and the far-field distributions of propagating modes from a high-power laser diode. Simple modeling was also performed and compared with experimental results. The simulated distributions were consistent with the experiment and permitted clarification of the configuration of the transverse modes of the laser.

pharmaceutical industry . It allows identifying and rapidly characterizing chemical compounds functional groups, molecular conformers, authenticating various drugs revealing presence of impurities and structural disorder in materials, studying stress distributions, temperature effects. Integration of Raman spectroscopy with Atomic Force Microscopy opens a wide range of new capabilities in imaging and characterizing pharmaceutical products. For example, AFM topograph provides information on size of grains, their shape, orientation and distribution. advanced AFM techniques also allow high resolution imaging of various physical properties of objects: local hardness, friction coefficient, electrical conductivity, surface potential and many others. In this application note integrated AFM aman instrument is used for comprehensive study of a pharmaceutical tablet to demonstrate capabilities of the technique. [1] , and . It is also useful in the and

We investigate optical properties of a new complex plasmonic nanostructure, which consists of a spherical metallic nanoshell and a small metallic nanoparticle ("nanoknob") situated on its surface. The plasmon resonance wavelength of the entire structure is guided by the geometrical and material properties of the nanoshell whereas the electromagnetic field of the incident light is localized and enhanced near the "nanoknob". The idea is supported with electromagnetic modeling and near-field optical microscopy imaging. In addition, we proposed and demonstrated a new method of nanoparticle precise manipulation under electron beam, which could be used in fabrication of such plasmonic structures and other nanosized elements.

Nanotubular structures in the B-C-N ceramic system represent an intriguing alternative to conventional carbon nanotubes. Because of the ability to widely vary the chemical composition of nanotubes within the B-C-N ternary phase diagram and to change the stacking of C-rich or BN-rich tubular shells in multiwalled structures, a wide horizon opens up for tuning nanostructure electrical properties. Pure carbon nanotubes are metals or narrow-bandgap semiconductors, depending on the helicity and diameter, whereas those of BN are insulators with a ~5.0 eV gap independent of these parameters. Thus, the relative B/C/N ratios and/or BN-rich and C-rich domain spatial arrangements, rather than tube helicity and diameter, are assumed to primarily determine the B-C-N nanotube electrical response. This characteristic is highly valuable for nanotechnology: while tube diameter and helicity are currently difficult to control, continuous doping of C with BN, or vice versa, proceeds relatively easily due to the isostructural nature of layered C and BN materials. In this article, recent progress in the synthesis, microscopic analysis, and electrical property measurements of a variety of compound nanotubes in the ceramic B-C-N system is documented and discussed.

The spatial resolution and high sensitivity of tip-enhanced Raman spectroscopy allows the characterization of surface features on a nano-scale. This technique is used to visualize silicon-based structures, which are similar in width to the transistor channels in present leading-edge CMOS devices. The reduction of the intensive far-field background signal is crucial for detecting the weak near-field contributions and requires beside a careful alignment of laser polarization and tip axis also the consideration of the crystalline sample orientation. Despite the chemical identity of the investigated sample surface, the structures can be visualized by the shift of the Raman peak positions due to the patterning induced change of the stress distribution within lines and substrate layer. From the measured peak positions the intrinsic stress within the lines is calculated and compared with results obtained by finite element modeling. The results demonstrate the capability of the tip-enhanced Raman technique for strain analysis on a sub-50nm scale.

Atomic Force Microscopy (AFM) has developed into a very powerful tool for characterization of surfaces and nanoscale objects. Many physical properties of an object can be studied by AFM with nanometer-scale resolution. Local stiffness, elasticity, conductivity, capacitance, magnetization, surface potential and work function, friction, piezo response—these and many other physical properties can be studied with over 30 AFM modes. What is typically lacking in information provided by AFM studies is the chemical composition of the sample and information about its crystal structure. To obtain this information other characterization techniques are required, such as Raman and fluorescence microscopy. The Raman effect (inelastic light scattering) provides extensive information about sample chemical composition, quality of crystal structure, crystal orientation, presence of impurities and defects, and so on. Information provided by Raman and fluorescence spectroscopy is complementary to the information obtained by AFM. So it is a natural requirement in many research fields to integrate these techniques in one piece of equipment—to provide comprehensive physical, chemical, and structural characterization of the same object. Of course, for routine studies of various samples, it is important to be able to obtain AFM and Raman/fluorescence images of exactly the same sample area, preferably with the same sample scan.

The resolution capabilities of near-field Raman spectroscopy based on a giant enhancement of the electric field near a nanosized metal probe are studied. As a test sample, bundles of single-walled carbon nanotubes deposited on glass substrates are used. It is shown that this method ensures a subwavelength spatial resolution of about 50 nm and demonstrates a Raman scattering enhancement of the order of 104.

A possibility to not only visualize but to locally probe a chemical structure, composition, conformational state and stresses on the nanoscale has stimulated the development of apertureless near-field vibrational spectroscopy and imaging with ultrahigh spatial resolution laying beyond the diffraction limit [1–3]. It has become possible due to the delocalization of evanescent waves (near-field) existing in the proximity of nano-sized objects with a sharp metal probe.

Low-temperature (T = 1.6 K) photoluminescence (PL) of individual CdSe/ZnSe/ZnMnSe quantum dots (QDs) with different magnitudes of the sp-d exchange interaction between the magnetic impurity ions and charge carriers has been studied in a magnetic field up to 12 T applied in the Faraday and Voigt geometry. The magnitude of the interaction was controlled by changing the fraction (ηe, h) of the squared wave function of charge carriers in the semimagnetic barrier by means of variation of the nonmagnetic (ZnSe) layer thickness. It is established that the sp-d exchange interaction leads to a change in the sign of the effective hole g factor even for ηe, h ∼ 5%, while further increase in the interaction magnitude is accompanied by a rapid growth in the magnitude of spin splitting for both electrons and holes. The quantum yield of PL exhibits a significant decrease due to nonradiative Auger recombination with the excitation of Mn ions only for ηe, h ∼ 12%, while the rate of the holes spin relaxation starts growing only for still higher ηe, h values. In a strong magnetic field perpendicular to the sample plane, the alignment of Mn spins leads to suppression of the Auger recombination only in the excited spin state. For a small rate of the hole spin relaxation, this leads to a rather unusual result: the emission from an excited trion state predominates in strong magnetic fields.

Detailed investigations of steady‐state photoluminescence (PL) in Cd(Mg,Mn)Te‐based asymmetric double quantum wells (ADQW) have been performed in magnetic fields up to B=10 T. PL spectra are determined by mutual exciton band alignment of adjacent wells in spin‐dependent ADQW potential. It is found that the populations of thermalized excitons in the wells are governed by intrawell spin relaxation, which allows to control spectral and polarization characteristics of semimagnetic ADQWs by varying of excitation conditions and structure parameters.

Exciton recombination in asymmetric CdMgTe / CdTe / CdMgTe / CdTe / CdMnTe double quantum wells (ADQW) with different barrier widths is studied in magnetic field up to 10 T. As grown structures were subjected to temperature annealing to introduce Mn and Mg atoms from the barriers into the CdTe quantum wells (QW). At low fields exciton transition in QW with magnetic impurity ( Mn ) is higher in energy than that in QW with nonmagnetic impurity ( Mg ), and interwell exciton relaxation is fast independently on the spin state. In contrast, at high fields, when the energy order reverses, an unexpectedly low relaxation rate of σ- polarized excitons from nonmagnetic QW to the ground σ+ polarized state in magnetic QW has been observed. Effect strongly correlates with hh–lh splitting value Δhh – lh and discussed in terms of valence band mixing. Such a slowing down of relaxation allows separation of oppositely polarized excitons in different QWs.

Underlying near-field optical effects on the nanoscale have stimulated the development of apertureless vibrational spectroscopy and imaging with ultrahigh spatial resolution. We demonstrate tip-enhanced Raman spectra of single-walled carbon nanotubes (SWCNTs), recorded with a scanning near-field optical spectrometer using both atomic force (AF) and shear force (SF) feedback lock-in regulation, and critically discuss the advantages and drawbacks of both operation modes. For accurate calculation of the enhancement factor obtained, we have analysed the tip shape and diameter by means of scanning electron and transmission electron microscopy (SEM and TEM). In our experiments we reproducibly attain diameter-corrected and area-corrected enhancement factors of up to ∼104 and ∼105, respectively, estimated as the linear ratio of near- and far-field intensities, and we are able to demonstrate near-field Raman imaging of SWCNTs with spatial resolution better than 50 nm.