• Anushree Roy

Articles written in Pramana – Journal of Physics

• Phonons and fractons in sol-gel alumina: Raman study

We report Raman scattering from the boehmite,γ-, δ- andα-phases of the alumina gel. Samples are characterized by transmission and scanning electron microscopy, X-ray diffraction and density measurements. The main Raman line in the boehmite phase is red-shifted as well as asymmetrically broadened with respect to that in the crystalline boehmite, signifying the nanocrystalline nature of the gel. Raman signatures are absent in theγ- andδ-phases due to the disorder in cation vacancies. We also show that low frequency Raman scattering from the boehmite phase resembles that from a fractal network, characterized in terms of fraction dimension$$\tilde d$$. Taking Hausdorff dimension D of the boehmite gel to be 2.5 (or 3.0), the value of$$\tilde d$$ is 1.33±0.02 (or 1.44±0.02), which is close to the theoretically predicted value of 4/3.

• A verification of quantum field theory — measurement of Casimir force

Here we review our work on measurement of the Casimir force between a large aluminum coated a sphere and flat plate using an atomic force microscope. The average statistical precision is 1% of the force measured at the closest separation. We have also shown nontrival boundary dependence of the Casimir force.

• # Pramana – Journal of Physics

Current Issue
Volume 93 | Issue 6
December 2019

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019