Ellipsometric study of nematic alignment on silicon oxides for display

Vertical Alignment Nematics (VANs) displays are a form of LCDs in which the liquid crystals naturally align vertically to the glass substrates. In spite of their name, the liquid crystal (LC) director is never exactly vertical, rather it always show a small angle with the normal to the sample plane called tilt that may vary throughout the cell bulk. Its values are ultimately determined by the pretilt, defined as the tilt angle on the surfaces in the absence of voltage

Pretilt effect on a vertically aligned liquid crystal cell for optical displays

Vertical aligned (VA) mode liquid crystal (LC) cells are very popular in transmissive directview and reflective projection displays because of high contrast ratio and wide viewing angle. A nonzero pretilt angle is generally used to avoid domain formation during molecular reorientation by electric field, as well as to reduce both driving voltage and response time. On the other hand, increasing the pretilt the quality of the dark state will be reduced, and thus an optimal value of pretilt has to be sought. To this aim, even different pretilt values on the two surfaces, yielding an asymmetric tilt distribution, could be considered. The pretilt effect on electro-optical properties of a VA LC cell has been investigated. Pretilt was controlled changing the angle of SiOx deposition on the substrate surfaces [1]. We employed Variable Angle Spectroscopic Ellipsometry [2] to obtain the tilt angle distribution versus the applied voltage. Finally, we compared experimental findings with simulated data at different anchoring energies. The results will be discussed

Reorientation of single walled carbon nanotubes in negative nematic liquid

Changes induced in liquid crystal (LC) properties by nanoparticle (NP) doping have attracted interest in the last decade. The anisotropic properties of carbon nanotubes (CNTs) make it interesting to study their reorientation in LC to verify the modifications induced in the electrooptic LC properties and the mutual influence in reorientation between LC and CNTs

Britain’s nuclear secrets: inside Sellafield

Lying on the remote north west coast of England, Sellafield is one of the most secret places in UK, and even one of the most controversial nuclear fuel reprocessing and nuclear decommissioning sites in Britain. The film director Tim Usborne let us enter into the world's first nuclear power station, revealing Britain's attempts to harness the almost limitless power of the atom. It is precisely the simplicity and the scientific rigor used in the film to speak of nuclear, which led this documentary to win the Physics Prize supported by the European Physical Society at the European Science TV and New Media Festival and Awards 2016

Physics, lasers and the nobel prize

Like every year, we have been waiting for the announcement of the most important award for natural sciences, the Nobel Prize in Physics. Perhaps it is since 2013, the year in which the award was given for the discovery of the Higgs boson, that the Nobel Prize has great media visibility. The public, scientific or otherwise, is waiting to know who will be awarded