Charged nano-domes and bubbles in epitaxial graphene.

For the first time, new epitaxial graphene nano-structures resembling charged 'bubbles' and 'domes' are reported. A strong influence, arising from the change in morphology, on the graphene layer's electronic, mechanical and optical properties has been shown. The morphological properties of these structures have been studied with atomic force microscopy (AFM), ultrasonic force microscopy (UFM) and Raman spectroscopy.

Anomalous multi-order Raman scattering in LaMnO3: a signature of quantum lattice effects in a Jahn-Teller crystal.

The multi-order Raman scattering is studied up to fourth order for a detwinned LaMnO3 crystal. Based on a comprehensive data analysis of the polarization-dependent Raman spectra, we show that the anomalous features in the multi-order scattering could be the sidebands on the low-energy mode at about 25 cm(-1). We suggest that this low-energy mode stems from the tunneling transition between the potential energy minima arising near the Jahn-Teller Mn(3+) ion due to the lattice anharmonicity and that the multi-order scattering is activated by this low-energy electronic motion.

Evidence for particle-shape sensitivity in the correlation between polarization states of light scattering.

The cross correlation between polarization states of scattered laser speckle as a function of scattering angle is observed for a range of spherical and nonspherical particle suspensions. A variation in the degree of correlation between polarization states is observed, and this information is indicative of the particle shape. A comparison with a theoretical model for small particles is made, suggesting that variations in polarization correlation with angle originate from the nonisotropic polarizability of nonspheres.

In-line assessment of pulmonary drug delivery using light obscuration.

A candidate optical technology for characterisation of the value and quality of the drug dose delivered to a patient from an inhaler is examined. The theoretical reasoning behind the design of this technology is presented with reference to the optical scattering of the drug cloud. A technical implementation is presented; based upon the light obscuration signature, observed in the delivery path during drug delivery.