Satyam Shinde

Spectral and DFT studies of anion bound organic receptors: Time dependent studies and logic gate applications

New colorimetric receptors R1 and R2 with varied positional substitution of a cyano and nitro signaling unit having a hydroxy functionality as the hydrogen bond donor site have been designed, synthesized and characterized by FTIR, 1H NMR spectroscopy and mass spectrometry. The receptors R1 and R2 exhibit prominent visual response for F− and AcO– ions allowing the real time analysis of these ions in aqueous media. The formation of the receptor–anion complexes has been supported by UV–vis titration studies and confirmed through binding constant calculations. The anion binding process follows a first order rate equation and the calculated rate constants reveal a higher order of reactivity for AcO− ions. The 1H NMR titration and TDDFT studies provide full support of the binding mechanism. The Hg2+ and F− ion sensing property of receptor R1 has been utilized to arrive at “AND” and “INHIBIT” molecular logic gate applications.

Electron - polar acoustical phonon interactions in nitride based diluted magnetic semiconductor quantum well via hot electron magnetotransport

In this paper the hot electron transport properties like carrier energy and momentum scattering rates and electron energy loss rates are calculated via interactions of electrons with polar acoustical phonons for Mn doped BN quantum well in BN nanosheets via piezoelectric scattering and deformation potential mechanisms at low temperatures with high electric field. Electron energy loss rate increases with the electric field. It is observed that at low temperatures and for low electric field the phonon absorption is taking place whereas, for sufficient large electric field, phonon emission takes place. Under the piezoelectric (polar acoustical phonon) scattering mechanism, the carrier scattering rate decreases with the reduction of electric field at low temperatures wherein, the scattering rate variation with electric field is limited by a specific temperature beyond which there is no any impact of electric field on such scattering.

Pressure dependent lattice specific heat and mode Grüneisen parameters for group III nitrides

The pressure dependent lattice specific heat and mode Gruneisen parameters for III–V nitrides have been calculated using a lattice dynamical model namely the rigid ion model which consists of a usual long range and short range potential. The Murnaghan’s equation of state is adopted for relating the volume dependence with pressure. The non linear least square fitting procedures to obtain the model parameters have been used. The results obtained using the present model calculation on mode Gruneisen parameters and specific are compared with existing experimental data and found in good agreement. There is a increase in in specific heat with pressure. The mode Gruneisen parameters show that the TA phonon mode is responsible for phase transition.