Physical Properties And Sensing Performance Of ZnO Based Nanoparticles Processed Through Tva Technique

Abstract

newlinevii newlineand#61623; A gas sensing setup was fabricated in-house and correlation among particle size, newlinemagnetic and sensing properties was studied using ZnO-based DMS materials. newlineAfter synthesis, all the prepared samples were characterized to investigate the newlineinfluence of the TVA technique on various physical properties at RT. First, from the newlineXRD results, a single-phase hexagonal wurtzite structure was observed in all pellet newlinesamples. The average crystallite size was found to vary inversely with the frequency of newlinevibrational energy, as expected. The closest approximation to the particle size from newlineHRTEM analysis agrees quite well with XRD. The SEM micrographs show uniform newlinedistribution of a large numbers of smaller grains of the pellet processed through TVA newlinetechnique. The grain size of NZO and CZO was found to be almost the same and larger newlinecompared to undoped ZnO. When analyzing UV-Visible spectra, it was observed that the newlinevalue of the optical bandgap varies inversely with the particle size in all the samples. newlineFTIR and RAMAN spectroscopy also supported XRD result showing single phase newlinehexagonal wurtzite structure for all samples. Due to vibrational annealing, decrease of newlinelattice defects such as oxygen vacancies was observed from RAMAN analysis. The newlinesemiconducting nature of all samples with n-type charge carriers was confirmed by Hall newlineeffect measurements at RT. Enhancement of magnetic property of both doped ZnO newlinesamples due to vibrational mechanical energy by novel TVA technique, were observed newlineby analysing SQUID at RT. The NZO sample showed better room temperature newlineferromagnetic behavior with prominent hysteresis loop area, whereas a mixed feature of newlineferromagnetism and paramagnetism behavior was observed for CZO samples. The value newlineof TC of NZO annealed with vibration was found to be at 382 K, indicating a positive newlinesign to be used as a promising candidate in spintronics devices at RT. newlineThe final part of this work addressed the impact of TVA on gas sensing applications. newlineFor this purpose, an in-house gas sensing chamber was fabricated and ac