National Institute of Technology, Meghalaya

About: National Institute of Technology, Meghalaya is a education organization based out in Shillong, India. It is known for research contribution in the topics: Control theory & Computer science. The organization has 503 authors who have published 1062 publications receiving 6818 citations. The organization is also known as: NIT Meghalaya & NITM.

Crystalline Acylhydrazone Photoswitches with Multiple Mechanical Responses

Abstract: The advancement of our understanding of stimuli-responsive molecular crystals has led to the realization that they hold great yet unexplored potential as adaptive materials. Although molecular crystals that exhibit a single mechanical response to a single input stimulus are now abundant, crystals that are capable of response to multiple stimuli are rather scarce. Here we report two photoswitchable acylhydrazone derivatives, Ac-1 and Ac-2, which respond to light as well as to mechanical force. Upon application of localized mechanical stress, the anhydrous (Ac-1a) and monohydrate (Ac-1h) crystals of Ac-1 undergo plastic shearing deformation and bending, whereas monohydrate crystals of Ac-2 undergo elastic deformation. When they are exposed to UV light, crystals of Ac-1h and Ac-2 undergo photoinduced bending; on the other hand, crystals of Ac-1a and thicker crystals of Ac-2 exhibit photosalient effect (light-induced leaping). It is demonstrated that the synergistic action of multiple stimuli (UV light and fo...

Spectral Anomaly in Raman Scattering from p-Type Silicon Nanowires

Abstract: An anomalous nature of Raman spectral asymmetry has been reported here from silicon nanowires (SiNWs) prepared from a heavily doped p-type Si wafer using a metal induced etching technique. Raman spectra of SiNWs prepared from two p-type Si wafers with different doping levels show different behaviors in terms of asymmetry as characterized by the asymmetry ratio. The SiNWs prepared from high doped p-type wafer show an anomaly in asymmetry in addition to the red shift and broadening of the Raman line shape due to the presence of the “FAno-quaNTUM” (FANTUM) effect. The heavy doping in the wafer provides a continuum of energy states to be available to interact with confined optic phonons which results in electron–phonon interaction. SiNWs prepared from low doped p-type wafer show a red shift and asymmetric broadening due to the quantum confinement effect alone. Careful analysis has been provided to clearly understand the role of Fano and quantum effects in p-type SiNWs with high doping and their relative contr...